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High-sensitive and Colorimetric Detection of Glucose with Glucose Oxidase-mimicking Gold Nanoparticles and Cerium Oxide Nanoparticles
������������ ������ ��� ������������ ��� 4��� 2500��� ������ ��������� ������ ������ ������������ ������������. ��������� ������, ������ ��������� ������������ ������������ ������ ������������ ������ ��������� ������������. ��������� ������������ ������ ������������ ��������� ��������� ��������������� ��������� ��������������������� ������������ ������������. ��� ��������� ��������������� ������������ ������������ ������ ��������� ��������� pH ��������� ������������, ��������� ������������ ��������� ������. ������ ��������� ��������� ������������ ��������������� ��������������� ��������� ��������� ������ ��������������� ������������ ��������� ��������� ��� ������ ������ ��������� ��������������� ������.
������, ��������� ������������ ��������� ��������������� ��������� ��������� ������������ ��������� ��������� ������. ������ ������������ ������ ������������������ ��������� ��� ������ ��������� ��������� ���������, ������������������ ������ ��� ��������� ��������� ��������� ��������� ���������. ������ ��� ��������� ��������� ������ ��������� ������ ��������� ������������ ��������� ��������� ������. ��������� ��� ��� ������ ��� ��������� ��������� ��������� ������ ������������ ��������� ������ ������ ������ ��������� ������������ ������. ������ ������������ ��������� ��������� ������ ��� ������������ ��������� ��� ������ ������ ��������� ������������ ���������������. ������ ��������������������� ��������� ������������ ��� ������ ��������� ���������������. ��������� (citrate)������ ��������� ��������� ��� ������ ��������� ��������� ������������ ��������� ������������ ������ ��������� ������������������, ��������� ��� ������ ��������� ��������� ������������ ������������ ��������� ��� ������ ������������ ������������ ���������. ������������������������ ������������ ��������� ������������ ������, ������������ ��������� ��������� ��� ������ ������������ ��������� ������������ ���������������. ������������ ��������� ������������������ ������������ ��� ������ ���������, ��������� ������������������ ��������� 3��� ������ 4��� ��������� ��������� ��������������� ������������ ������ ������ ������ ��������� ������������ ��������� ��������� ��������� ������ ��������� ���������, ������ ������������ ������ ��������� ��� ������ ��������� ������.
������ ��� ������ ��������� ������������������, TEM��� UV -vis spectrum��� ������ ������ ������������. ������������ ��������� ������ ��������� ��������� ��� ������ ��������� ��������� ������ ��������� ��������� ������������ ��������� ������������ ������ ��������������� ������ ��������� ���������������. ������ CCK, LDH ������ ������ ������ ������������ ��������� ���������������.
��� ��������� ������ ������������ ������, ������ ��������� ������������ ������ ������ ��������� ������ ������������ ������������ ��������� ��������� ������������ ������ ��������� ������ ��������� ��� ������ ��������� ���������������. ��� ��������� ��������� ������������ ��� ������ ������������ ��������� ��������� ������ ������ ��������� ���������������. ������������������ ������ ��� ��������� ���������(0.1-0.6 mM) ������ ��������� ��������� ��� ������ ������ ������ ��������� ������ ������������ ������������. ��������� ��������������� ������ ������, ������ ������������ ������������ ������ ������������ ��� ��������� ��������������� ��������� ������ ��� ������ ������ ������ ������ ������ ��� ������ ��������� ��������� ��� ������ ���������.Diabetes Mellitus (DM) is a popular disease nowadays. Patients with diabetes or pre-diabetes need periodic blood glucose measurements to maintain normal condition. Currently, the most popular blood glucose meter is a method of measuring blood glucose electrochemically by pricking a finger with a needle. This conventional blood glucose meter contains glucose oxidase which is sensitive to changes in temperature and pH, easily denatured and expensive. To make up for this, I was thinking about replacing the enzyme role with nanoparticles. On the other hand, the sensor for measuring blood glucose is invasive, so it causes pain and there is a risk of infection. Since it is already known that glucose concentration in the tear forms a proportional relationship with blood sugar, I planned to detect tear glucose which can be measured noninvasively. However, the glucose change in tears is very slight and much lower than in blood. To detect these slight changes, nanomaterial capable of detecting minute tear glucose is needed. Thus, gold nanoparticle was selected as a substitute of glucose oxidase in this research. Previous studies have shown that citrate-capped AuNP has glucose oxidase-mimicking activity. Also, according to research results, these nanoparticles are more sensitive to glucose than glucose oxidase. Therefore, it is possible to detect glucose at a low concentration.
In this study, I made a system which can detect tear glucose by some colorimetric change so that it can be measured with human eyes. Citrate-capped gold nanoparticles which mimic glucose oxidase activity were first synthesized. The aspects that affect glucose-oxidase mimicking activity of gold nanoparticles such as capping agents and the size were analyzed and optimized for better sensitivity to glucose. With an assay for H2O2, it was confirmed that citrate is the most suitable capping agent for glucose detection. Also, it was confirmed that the smaller the particle sizes of AuNP, the greater the reactivity of glucose. The smallest size of citrate-capped AuNP with 3.5 nm in diameter was selected and proved that it has no cytotoxicity through cytotoxicity tests such as CCK and LDH assays. To detect tear glucose concentration by checking the color change with naked eyes, cerium oxide particles were used because they exhibit color change by reacting with H2O2 which was produced when gold nanoparticles react with glucose. This allows patients to identify glucose levels with naked eyes by simply observing color changes.
Overall, this platform is sensitive, nontoxic so it can be further used as non-invasive biosensors for detecting tear glucose.Maste
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������ ������������ ��������� ������ ��������� ������ ������ ��������������� ������ ��������������� ��������������� ��������� ��������� ������ ��������� ������������ ��� ������ ������������ ��� ��������� ������ ������������ ������. ��������� ��������������� ������ ������ ������������ ��������� ������ ������ ������, ������ ������, ������ ������ ��� ��������� ������ ������ ������ ��� ������ ���������. ��������� ��������� ������ ��������� ������ ������������������ ��������������� ��������� ��������� ���������. ������ ������ ������ ������������ ��������� ������ ������ ������ ��������� ������ ��������� ��������� ������ ��������� ��� ������ ��������� ������������ ������ ������������ ������. ������ ������ ���������(Fluorescence lifetime imaging microscopy)��� ������ ��� ������ ������������ ��������� ��������� ��������� ��� ��� ������ ��������� ������������ ������ ������������. ��������� ������ ��������� ������������ ������ ������ ��������� ��������������� ������ ������������, ������������ ������ ��������� (Analog mean-delay)��� ������������ ��������� ������������ ��������� ������������ ������ ��������������� ��������� ������ ��� ���������. 2������ ��������� (Two-photon excitation microscopy)��� ������ ������ ��������� ������������ ������������ ������ ������ ������������ ������������ ������ ������ ������ ������ ��������� ������ ��� ������. ������ 2��� ��������� ��������� ��������� (Second harmonic imaging microscopy)��� ������ ��������� ������������ ������������ ������ ������ ��� ���������, ��������� ��� ������ ��������� ������ ������ ������������. ��� ��������������� ��������� ���������, 2��� ��������� ��������� ���������, ������������ ������ ������ ������ ������ ������������ ������������ ������������ ������ ������ ��������� ��������� ������������ ��������� ������������������ ��������������� ������.
������ ��������� ��������� ������ ������ ������ ������ ������������ ������������ ������ ������������ ���������������, ��������������� ��������� ������ ������������ ���������������. ������������������ ������ ������ ��������� ������������ ������ ��������� ������������ ������ ��������� ������������������ ������ ������������ ��������� ��������� ���������������. ������ ������ ������������ ��������� ������������ ���������, ��������� ������ ������ ������������ ���������, 2��� ���������, ������ ������ ��������� ������������ ��������� ������������ ���������������. ��������� ������ ������������ ���������, 2��� ���������, ������ ������ ��������� ��������� ������������.
������ ������, ��� ������������ ������ 2��� ��������� ��������� ��������������� ��������� ��������� ��������� ��� ��������������� ��������� ��� ���������. ������ ������ ������ ��������� ������ ��� ��������� ������������ ������������ ��� ��������� ���������������. ��������������� ��������������� ������������ ��������� ������������������ ��������� ������ ��������� ��������� ���������������, ��������� ��������� ��������������� ������ ��������� ��������� ������������ ������������������, ��������������� ������ ��������� ��������� ������������ (microvilli)������ ��������� ��������� ������������. ������ ��������������� 2��� ��������� ��������� ������ ������ ������ (Instrumental response function)��� ������������ ��� ������ ��������� ��������� ��������������� ���������������. ������ ��������������� 2��� ��������� ��������� ������������ ������������������, ������ 2������ ������ ��������� ��������������� ��������� ��� ���������, ������������������ ������������ ������ ������ ��������� ������������.
��� ��������������� 2������ ���������, 2��� ��������� ��������� ���������, ������ ������ ������������ ��������� ��������� ������������ ���������������, ������ ������ ������, ������ ��������� ��������������� ��������� ��������� ��� ���������. ��� ������������ ��������� ��������� ������������ ��������������� ��������� ��������� ��� ��������� ���������.Optical microscopy has been considered as a powerful tool in biological and medical field due to its imaging performance in terms of resolution. Optical microscopy can detect chemical information such as molecular binding, distribution, ion concentration as well as structural information recently. However, with one information of structure or molecule, it is hard to understand the state of a biological tissue. Therefore, multimodal optical microscopy incorporating various microscopes has become a hot topic in the field of optical microscopy. A fluorescence lifetime imaging microscopy (FLIM) have been used popular in multimodal microscopy because it can visualize the distribution of molecules in various biological tissues. The imaging speed of FLIM was usually too slow for real-time imaging. Using analog mean-delay (AMD), high-speed FLIM technique, some studies achieved faster FLIM imaging, but the FLIM information was restricted to tissue surface. These issues can be solved by combining AMD-FLIM with a two-photon excitation microscopy (TPEM) which can acquire fluorescence signals from deep tissues. Furthermore, a second harmonic imaging microscopy (SHIM) is also capable of deep tissue imaging. It can target specific biological molecules such as collagen, myosin, etc. By integrating those three different modalities introduced above, deep tissue structural and biochemical imaging can be achieved. In this study, a high-speed multimodal microscopy utilizing two-photon excitation microscopy (TPEM), second harmonic imaging microscopy (SHIM), and fluorescence lifetime imaging microscopy (FLIM) was proposed.
A femtosecond pulsed laser was used for light source and analog mean-delay (AMD) was adopted for fast FLIM. Imaging error occurred due to the discrepancy between the laser sync and digitizer sampling. These errors could be measured and reduced by imaging acquisition software including sampling point skipping algorithm. Then, the remaining errors were corrected numerically using standard sample target. After the compensation, post-processing was applied to enhance image quality. The whole image acquisition time was recorded including the error correction processes. The FLIM performance was tested with Coumarin 6, and rhodamine B. At last, the developed system was validated with mouse lung, kidney, and rabbit artery.
With mouse lung, SHIM and TPEM images were acquired and reconstructed in 3D. Strong second harmonic signal was detected from the surface, and TPEM image showed inner tissue structures. And two regions with different lifetime were detected probably denoting pneumocytes type I and II. With mouse kidney, TPEM images showed some tubular structures which regarded as proximal and distal tubules. Distinct lifetime differences between tubular structures and inner wall were observed. Probably, the lifetime signal of inner wall originated from actin filaments of brush border. With rabbit artery, SHIM was used as instrumental response function (IRF). As the result, SHIM, TPEM and FLIM images could be acquired simultaneously. Abundant second harmonic signal was observed in tunica adventitia. And strong two-photon fluorescence was found from tunica media, and a FLIM image was acquired which regarded as elastin fluorescence.
In this study, a high-speed multimodal microscopy was developed which integrated TPEM, SHIM and FLIM. It was demonstrated with mouse lung, kidney, and rabbit artery and their structural, and chemical information were observed. We expected that developed system gives contributes to various biomedical studies.Maste
Factors influencing resubstantiation of child neglect in South Korea: A comparison with other maltreatment cases
While a high prevalence of child neglect cases has been reported by Child Protective Services (CPS) in Western countries, child neglect cases reported to South Korea's Child Protection Agency (CPA) present different trends than those in Western countries. Nevertheless, child neglect is an understudied area within child welfare. Thus, a need exists to investigate the unique characteristics of child neglect cases substantiated by the CPA in Korea. This study investigates the unique characteristics of child neglect cases and examines how factors associated with the resubstantiation of these cases differ from those of other maltreatment cases. Using CPA administrative data, we employed a multilevel discrete���time hazard analysis to analyze the risk and protective factors associated with the resubstantiation of child neglect cases and compared the results with other maltreatment cases. In both cases, younger children, perpetrators with alcohol problems, families receiving welfare, and months of agency operation were associated with resubstantiation. For child neglect cases, the provision of child and parent services, and CPAs located in metropolitan area were protective factors that reduced the risk of resubstantiation. The finding in this study highlights the need to expand the provision of services to child neglect cases to prevent resubstantiation.This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI16C1419) and by the “Overseas Training Expenses for Humanities & Social Sciences” through Seoul National University (SNU)
Factors associated with non-initiation of latent tuberculosis treatment among healthcare workers with a positive interferon-gamma releasing assay
Despite widespread use of the interferon-gamma release assay for the diagnosis of latent tuberculosis infection (LTBI), the initiation rate of and factors associated with LTBI treatment among healthcare workers (HCWs) have not been studied in depth. The aim of this study was to evaluate the initiation rate of LTBI treatment and also to identify any factors associated with non-initiation of LTBI treatment among HCWs. A retrospective cohort study of 293 HCWs with LTBI was performed at a teaching hospital in Korea. LTBI was diagnosed using QuantiFERON-TB Gold In-Tube tests (Cellestis Ltd., Carnegie, VIC, Australia). Of the 293 HCWs with LTBI, 189 HCWs (64.5%) visited an outpatient clinic for a medical consultation regarding LTBI treatment. Of these, 128 (67.7%) consented to LTBI treatment for a 43.7% LTBI treatment initiation rate. Upon multivariable analysis, having a liver disease or currently taking hepatotoxic drugs (adjusted odds ratio [OR] = 12.03, 95% confidence interval [CI] = 3.12-46.35), being a physician (adjusted OR = 14.01, 95%Cl = 2.82-69.74) and other patient-related HCWs (adjusted OR = 3.58, 95%Cl = 1.46-8.78), and years of employment ��= 20 years (adjusted OR = 4.77, 95% CI = 1.74-13.12) were independent factors associated with the non-initiation of LTBI treatment. Upon bivariate multivariable analysis, while having a liver disease or currently taking hepatotoxic drugs (adjusted OR = 12.85, 95% CI = 3.06-55.92), being a physician (adjusted OR = 28.43, 95% CI = 4.78-169.28) and other patient-related HCWs (adjusted OR = 4.80, 95%Cl = 1.56-14.74), and years of employment ��= 20 years (adjusted OR = 4.55, 95%Cl = 1.37-15.15) were factors associated with no outpatient clinic visit for a consultation of LTBI treatment, having a liver disease or currently taking hepatotoxic drugs (adjusted OR = 11.76, 95% CI = 2.68-51.73) and years of employment ��= 20 years (adjusted OR = 5.29, 95%Cl = 1.38-20.19) were factors associated with refusal of LTBI treatment after a consultation. The overall initiation rate of LTBI treatment was suboptimal in HCWs with LTBI diagnosed using an interferon-gamma releasing assay. Having a liver disease or currently taking hepatotoxic drugs, being a physician and other patient-related HCWs, and years of employment ��= 20 years were associated with non-initiation of LTBI treatment.This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI15C1234)
Fund Recommendations and Fund Performance
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Given the wide variety of equity funds in the public offering market, fund investors find it difficult to select funds that match their investment preferences. Therefore, equity fund investors pay greater attention to funds that are recommended by sales professionals from banks or securities companies. They rely on brokers’ recommendations when selecting equity funds instead of conducting rigorous analysis. Therefore, brokers’ fund recommendations carry great importance from the perspective of investor protection. However, due to the limitations of data collection, research on this topic has not yet been conducted in Korea. Analysis of fund recommendations would have valuable implications for investor protection. Studies of equity funds have paid much attention to overall fund performance, fee structures, or the role of fund distributors (e.g., Won, 2009; Kim, 2011; Kho and Baek, 2013). However, although performance analysis of fund recommendations is important, research has paid little attention to the topic. To the best of our knowledge, no study has considered the real performance of recommended funds in Korea, as fund brokers do not voluntarily disclose data related to fund sales or the return performance of recommended funds. As each broker sells tens of funds, it is difficult to estimate the return performance of the funds of each broker. However, fund evaluation companies have recently begun to build data on funds recommended by each vendor, so analysis of the performance of recommended funds is possible. We empirically analyze the determinants of brokers’ fund recommendations and the performance of recommended funds in two ways. First, we analyze the factors that determine brokers’ fund recommendation decisions. Second, we analyze the future performance of the recommended funds. To confirm our findings, we use propensity score matching to compare the performances by matching recommended and non-recommended funds with similar characteristics. To investigate possible conflicts of interest in the fund recommendations, we focus on the levels of fees and commissions and the relationships between brokers and fund managers. We pay attention to the possibility that the seller, in recommending a fund to a customer, acts on behalf of the seller or affiliated fund manager rather than prioritizing the customer’s benefit. The results of this study are as follows. Funds with front-end loads and/or funds of asset management firms with no affiliated brokerage companies are more likely to receive recommendations from brokers. Furthermore, funds of large asset management companies receive more recommendations than those of medium or small management companies. In addition, new funds with short operating periods are selected as recommended funds, and new funds from affiliate management firms are more likely to be recommended. The performance of those recommended funds turns out to be inferior. Based on the results of analysis of the profitability of broker-recommended funds, we find that recommended funds do not perform better than funds that are not recommended by brokers. This result does not support the general perception that brokers have fund-selection ability. However, no evidence supports the view that the inferior performance of broker-recommended funds is caused by the self-interest of the broker who pursues the profit of a subsidiary asset management company. Recommended funds of affiliated asset management companies record better performance than those of non-affiliated companies. In particular, when the seller recommends a newly launched fund of the affiliated management company, its return performance is better. Thus, we conjecture that the inferior performance of a recommended fund is not due to the broker’s intention to subsidize an affiliated asset management company. This result suggests that a broker, through an information transfer from affiliated fund managers, plays a role in mitigating the information asymmetry of newly launched funds. It also supports the view that the affiliate broker analyzes the newly launched fund more accurately. Our study shows that broker-recommended funds generally exhibit inferior return performance. This result suggests that fund sellers are required to improve their fund selection ability to enhance the protection of fund investors. Sellers must improve their fund analysis capabilities through internal research and workforce reinforcement. Our study has some limitations in the sense that it covers a relatively short period due to the insufficient accumulation of fund recommendation data. Further research should be conducted to review the robustness of the analytical results over a wider analysis period after equity fund data are accumulated more broadly.��� ��������� ��������������� ������ ������������������������ ��������������� (HY-2017������)
Accrual-based and Real Earnings Management Using Related Party Transactions
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This paper examines Korean firms’ accrual-based and real earnings management using related party transactions.
The findings in this paper are as follows. First, the results show that as the sales/revenue transactions of related parties increase, earnings are managed by using production costs and discretionary expenses and as the purchase/expense transactions of related parties increase, earnings are managed by using sales and production costs. In case of sales/revenue transactions, earnings management using production costs and discretionary expenses is limited to domestic subsidiary transaction. On the other hand, in case of purchase/expense transactions, earnings management using sales and production costs is observed both in domestic and foreign subsidiary transactions. Second, in business group, real earnings management which undermines long-term performance decreases as the sales/revenue transactions of related parties increase, while accrual earnings management which does not affect long-term performance increases as the purchase/expense transactions of related parties increase. Third, as the related party transaction increases, there is a complementary relationship between accruals earnings management and real earnings management and this relation is discriminatory in domestic transactions.��� ��������� ��������������� ������������������������������ ���������������(HY-2017)
Fabrication of Spheroids with Uniform Size by Self-Assembly of a Micro-Scaled Cell Sheet (mu CS): The Effect of Cell Contraction on Spheroid Formation
Cell spheroid culture can be an effective approach for providing an engineered microenvironment similar to an in vivo environment. Our group had recently developed a method for harvesting uniformly sized multi cellular spheroids via self-assembly of micro-scaled cell sheets (mu CSs) induced by the expansion of temperature-sensitive hydrogels. However, the mu CS assembly process was not fully understood. In this study, we investigated the effects of cell number, pattern shape, and contractile force of cells on spheroid formation from micropatterned (width of square pattern from 100-300 mu m) hydrogels. We used human dermal fibroblasts (HDFBs) as a model cell type and cultured them for 24 and 72 h. The self-assembly of mu CSs cultured on square micropatterns for 72 h rapidly occurred within 4 min after reducing the temperature from 37 to 4 degrees C. In addition, the size distribution of spheroids was narrower with mu CSs from a 72 h culture. Treatment with a ROCK1 inhibitor disrupted cytoskeletal actin fibers and the corresponding mu CSs were not detached from the hydrogel. The assembly of the mu CS was also affected by the micropattern shape, and the spheroid harvest efficiency was decreased to 60% when using a circular micropattern, which was explained by the stress direction on the circular versus square micropattern upon hydrogel expansion. Therefore, we confirmed that the factors controlling cell-cell interactions are important for spheroid formation using micropatterned hydrogel systems. Finally, the mu CSs with dual layers of HDFBs labeled with DiD and DiO dyes resulted in the formation of spheroids with discretely localized colors within the core and shell, respectively, which suggests an outside-in assembly of detached mu CSs. In consideration of these complex environmental factors, our system could be utilized in various applications as a three-dimensional culture system to fabricate cell spheroids.This work was supported by a grant from the National Research Foundation of Korea, which is supported by the Korean government (MEST) (NRF-2016R1A2B3009936) and Technology Innovation Program (10050526, Development of disposable diaper based on biomass-oriented biodegradable super-absorbent polymers) funded by the Ministry of Trade, Industry & Energy (MI, Korea)
Analogous crystal orientation for immobilizing rGO/ZrO2/Ag3PO4 nanocomposite on a fluorine-doped tin oxide substrate
Immobilization of nanocomposites without compromising their photocatalytic performance is a challenging task. Here, we report a new method that utilizes analogous crystal orientations and similarities in interplanar spacings for photocatalyst immobilization. The photocatalyst rGO/ZrO2/Ag3PO4 was synthesized using a green hydro thermal method. A primary layer of ZrO2 and a secondary layer of rGO/ZrO2/Ag3PO4 composite were deposited on a fluorine-doped tin oxide (FT0) substrate. The analogous crystal orientation and interplanar spacing of ZrO2 between the two layers resulted in composite immobilization on the FTO substrate. X-ray diffraction analysis confirmed that ZrO2 growth occurred along the same crystal planes in both layers. The film exhibited a low band gap energy (2.6 eV) and excellent light absorption. Photocatalytic performance achieved 92% para-nitrophenol degradation in 150 min. The degradation performance of this immobilization method was 43% higher than those of rGO/ZrO2/Ag3PO4 films deposited with conventional binder approaches. The quantum yield of the system was 3.46 x 10(-5) moleculesphoton-i. Finally, a figure of merit based on different parameters was determined and compared with previous results to assess the practicality of this system.This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, & Future Planning (No. 2018R1A2A1A05023555)
Nanomaterials for the adsorptive treatment of Hg(II) ions from water.
The prolific growth of modern industrial practices has been accompanied by the extensive release of effluents rich in toxic byproducts (e.g., mercury). Therefore, the abatement of such byproducts has become a crucial prophylactic measure to protect human health, ecosystems, and food resources. Although several conventional techniques are available, it is highly desirable to develop more efficient and economical adsorbents for such application. In this regard, the development of multifunctional, tailorable, and advanced materials with very large surface areas and flexible surface active sites is desirable to expand effective options available for abatement technology. This review explores recent trends and advancements in nanomaterial technology for the mitigation of mercury. Further, the current hindrances and future prospects in related research fields are discussed in depth.This research acknowledges the support made by the R&D Center for Green Patrol Technologies through the R&D for Global Top Environmental Technologies funded by the Ministry of Environment (MOE) as well as by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (Grant No: 2016R1E1A1A01940995). KHK also acknowledges support made by the Korea Ministry of Environment (MOE) (2015001950001) as part of "The Chemical Accident Prevention Technology Development Project" and the support of "Cooperative Research Program for Agriculture Science and Technology Development (Grant No: PJ012521032018)" Rural Development Administration, Republic of Korea
Analyzing Locational Characteristics of Convenience Stores in Seoul Using Negative Binomial Regression
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This study analyzes the effects of spatial characteristics on convenience stores in Seoul on the premise that they should affect the location of convenience stores. In the analysis, the entire area of Seoul is divided into 400m × 400m grids, first of all. In the next step, the spatial sampling technique is used to obtain a grid separation of 1,600m, which is the distance that the Moran’s I measure is significantly lowered. This study employs negative binomial regression to analyze the derived data. The dependent variable is number of convenience stores and locational characteristics of the grids are the independent variables in the analysis. The analysis finds that almost all the independent variables do not have significant relations with the dependent variable except the number of different businesses. The analysis results are judged to imply the saturation and poor location of convenience stores in Seoul due to the increase of small businesses