240 research outputs found
On the spatial and temporal coherence of wireless vehicular short range channels
No full textWe consider spatial and temporal coherence of the vehicle–to–vehicle (V2V) wireless communication channel with focus on a suburban residential highway. The dominant reflectors in such an environment are vehicles passing in the adjacent lane and houses
along the road. Instead of treating the reflectors as point targets, the V2V short range propagation environment requires partitioning of the illuminated reflector side into
sufficiently small tiles. The channel transfer function is obtained as a superposition of specular reflections from the tiles, the line–of–sight (LOS) component, and the ground reflection. The tile size is selected to ensure that the ratio of the tile area to the tile–to–receiver distance satisfies the far field conditions. The reflected power is described by the tile radar cross section (RCS). The bistatic physical optics RCS model is adapted to account for the tile’s orientation with respect to the ray geometry. We apply the superposition model to the numerical analysis of two general scenarios
for a 22MHz channel in the 2.4GHz band. The first scenario considers a single vehicle reflector passing in the lane adjacent to the V2V communication pair. Both the vector network analyzer (VNA) experiments and the tiling model analysis illustrate that repositioning of the reflector, the transmitter, or the receiver by a few centimeters results in change of the signal power by several decibels. The second scenario analysis characterizes the channel coherence statistics for the
suburban residential highway. We consider the V2V single lane LOS and non–LOS geometries, where in the latter the receiver is shadowed by a large vehicle. The reflectors are both houses and vehicles passing in the opposite direction. The measure of channel coherence is the normalized spatial covariance calculated by correlating transfer functions corresponding to feasible receiver position pairs and performing spatial smoothing. The area of feasible receiver positions is divided into contiguous squares
whose size ensures wide sense quasi–stationarity within the square. Irrespective of direction the correlation remains high and a typical sedan roof usually does not provide sufficient spacing to obtain average inter–antenna correlation lower than 0.5. The upper bound on coherence time extends over the transmission time of multiple packets for systems in the considered band, and does not allow for usable time diversity.Ph.D.Includes bibliographical referencesIncludes vitaby Haris Krem
PENGARUH PEMILU SERENTAK TERHADAP RETURN SAHAM DI INDONESIA (Studi Kasus Saham LQ-45 di Bursa Efek Indonesia)
No full textPemilu adalah salah satu peristiwa politik yang bisa mempengaruhi perekonomian suatu negara, terlebih pemilu tersebut dilaksanakan secara serentak. Pasar modal sebagai salah satu insrumen ekonomi tidak terlepas dari pengaruh lingkungan, baik lingkungan ekonomi maupun lingkungan non-ekonomi. Penelitian ini bertujuan untuk menganalisis reaksi pasar modal terhadap peristiwa anomali pasar di Indonesia, dalam hal ini Pemilu serentak (Presiden dan Legislatif) tahun 2019. Reaksi pasar saham diukur dengan abnormal return dan volume aktivitas perdagangan saham. Populasi dalam penelitian ini adalah perusahaan yang sahamnya tercatat dalam LQ-45. Penelitian ini menggunakan even study (studi peristiwa). Hasil penelitian menunjukkan bahwa ada reaksi investor di mana 10 hari sebelum dan 10 hari sesudah 17 April 2019 pemilu serentak. Kondisi ini menunjukkan adanya optimisme investor bahwa pemilu akan diadakan pada 17 April 2019. Hal yang serupa dengan volume rata-rata perdagangan saham sebelum dan sesudah pemilu serentak 17 April 2019 juga mengalami peningkatan
PENGARUH ETIKA PROFESI AKUNTAN DAN TEKANAN KETAATAN TERHADAP KUALITAS PELAPORAN KEUANGAN DENGAN KUALITAS SISTEM PENGENDALIAN INTERNAL SEBAGAI VARIABEL MODERASI (STUDI KASUS PT BANK MANDIRI TBK)
No full textThis study aims to examine the impact of Accounting Professional Ethics and Compliance Pressure on the Quality of Financial Reporting, with the Quality of Internal Control Systems (ICS) as a moderating variable. The research focuses on the banking sector, specifically PT Bank Mandiri (Persero) Tbk, to evaluate how internal and external pressures interact with ethical standards. The results indicate that Accounting Professional Ethics contributes significantly and positively to the quality of financial reporting. Conversely, Compliance Pressure exerts a negative impact, potentially compromising reporting integrity. Furthermore, the analysis reveals that a high-quality Internal Control System acts as a robust moderator; it amplifies the positive influence of ethical behavior and effectively mitigates the adverse effects of compliance pressure.These findings underscore the critical necessity of reinforcing ethical frameworks and strengthening internal control mechanisms within accounting practices. For institutions like PT Bank Mandiri Tbk, prioritizing these elements is essential to safeguard the transparency and optimal quality of financial disclosures
KEMANDIRIAN USAHA UMKM DI DAERAH PASIR PESISIR: PERAN NILAI JIWA WIRAUSAHA DAN PERILAKU KEWIRAUSAHAAN
No full textThe aim of this research is to find out how entrepreneurial behaviour and enthusiastic values influence entrepreneurial independence. The aim of this research is also to find out how entrepreneurial behaviour and enthusiastic values influence business independence. Primary data obtained from respondent questionnaires was used in this research. This research uses a purposive sampling technique, which involves establishing certain criteria for selecting samples. Twenty MSMEs that met certain requirements were obtained using this strategy. Multiple regression, t test, f test, determination test, classical assumption test, and descriptive test are some of the data analysis techniques used. Statistical package for social sciences (SPSS) version 25 was the data analysis tool used. The findings of this research indicate that cultivating an entrepreneurial mindset and acting in an entrepreneurial manner can significantly and profitably increase a company's level of independence
Explosive indentation study of B4C-TiAlx composites fabricated by the dipping exothermic reaction process
No full textThe aim of this study is to fabricate a high volume fraction B4C-reinforced intermetallic matrix composite by the dipping exothermic reaction process and investigate the shock impact damage response of composites by explosive indentation experiment. It has been shown that the final microstructure of the dipping exothermic reaction process-fabricated composite can be tailored by treatment of the constituent powders and post heat treatment. The hardness and impact damage resistance of the fabricated composites were evaluated.This work is supported by grants (No. N62649-03-0007) from AROFE(US Army
Research Office Far-East). The author thanks Drs. J. W. McCauley of ARL, Sean Yu and
R. Olesinskiof AROFE
Increasing the Performance of Passive Communication with Ambient Light
No full textMost wireless communication technologies have been using the Radio Frequency (RF) spectrum for decades. Due to the popularity of the Internet of Things (IoT), the RF spectrum has started to become densely populated. Researchers have begun to explore other bands of the electromagnetic spectrum that can be utilized as a communication media. One of the promising choices is the visible light spectrum.Visible Light Communication (VLC) refers to the wireless communication technology that utilizes the visible light spectrum. This spectrum is thousands of times wider than the Radio Frequency (RF) spectrum and is license-free. In VLC, data is transmitted by turning a light source on and off. However, not every light source can be controlled. Passive light sources such as the sun provide an immense amount of light that can be used for wireless communication if we can develop ways to modulate them. One of the researches that use ambient light to create a wireless link is LuxLink. LuxLink uses liquid crystal shutters to control passive light sources and provides low energy, reliable, and flicker-free (safe) communication. This thesis addresses several problems that the current LuxLink system has.We present LuxLink+, an extension of LuxLink that provides two main improvements. Firstly, the data rate of the system is relatively low (80~bps). To increase the data rate, we provide a thorough analysis of the system’s bandwidth. Afterward, we modify the modulation technique, which increases the data rate to 1000~bps at a range of 1.5~m.Secondly, the system has a static data rate, which means that the system cannot adapt its data rate to changes in the environment. We implement a rate adaptation algorithm that can change its data rate accordingly. LuxLink+ improves the average throughput of the system by up to 85 percent compared to LuxLink.Electrical Engineering | Embedded System
Performance investigation of an integrated wind energy system for co-generation of power and hydrogen
No full textIn this paper, a wind turbine energy system is integrated with a hydrogen fuel cell and proton exchange membrane electrolyzer to provide electricity and heat to a community of households. Different cases for varying wind speeds are taken into consideration. Wind turbines meet the electricity demand when there is sufficient wind speed available. During high wind speeds, the excess electricity generated is supplied to the electrolyzer to produce hydrogen which is stored in a storage tank. It is later utilized in the fuel cell to provide electricity during periods of low wind speeds to overcome the shortage of electricity supply. The fuel cell operates during high demand conditions and provides electricity and heat for the residential application. The overall efficiency of the system is calculated at different wind speeds. The overall energy and exergy efficiencies at a wind speed 5 m/s are then found to be 20.2% and 21.2% respectively
Multigeneration system exergy analysis and thermal management of an industrial glassmaking process linked with a Cu–Cl cycle for hydrogen production
No full textA multigeneration system for hydrogen production linked with a glassmaking process via thermal management is examined in this study. The exhaust gas is interconnected with a Rankine cycle and the copper-chlorine (Cu–Cl) cycle for hydrogen production. The present system consists of a steam Rankine cycle, Cu–Cl cycle with multistage compression, double-stage organic Rankine cycle, and multi-effect desalination system. A Cu–Cl cycle based on the four-step model is employed with the proposed system. The useful system outputs are electricity, hydrogen, and fresh water. The simulation software packages utilized in the analysis and modeling are Engineering Equation Solver and Aspen Plus. The energy efficiency of the overall system is 36.5% while 38.1% is the exergy efficiency. The parametric studies are conducted to investigate the system performance. In addition, the effects of exhaust gas variables, such as flow rate, temperature, and pressure are examined to investigate the system performance
Leadership strategies for embedding sustainability and resilience in organizations with an emphasis on sustainable energy
No full textEfficient strategies to embedding sustainability in an organization are frequently linked to effective leadership. By design, changes in direction within an organization may lead to alterations in commitment or perceived significance of sustainability in organizations. While some organizational leaders are interested in embedding sustainability within a structure, other leaders believe in leaving the legacy behind and permanently influencing sustainability efforts. To confirm or dispel the underscored notion of the importance of leadership in embedding sustainability in organizations, a qualitative methodology approach to interviews, document analyses, and literature review is utilized. The research inquiry includes in-person interviews with top city staff and elected officials in a large Midwestern city and a review of the internal documents and reports. The end goal of the research is an examination of the role both elected and appointed officials have in embedding sustainability within cities, and whether a change in leadership may have an impact on continuity of sustainability implementation and
long-term viability of such policies. The paper focuses on the application of sustainable energy policies within a local government organizational structure as a mean of constructing a better understanding of leadership on sustainability implementation and embedment. While the further inquiry is needed, the research points out that an active partnership between city managers, administrators, and elected officials must be in place to support integrating sustainability from within and that sustainability thrives where exhaustive leadership support such
initiatives and efforts.Journal ArticleFinal article publishe
Measuring the Sustainability Impact in Local Governments Using the Quadruple Bottom Line
No full textSustainability is utilized by cities to enable a multifaceted, cross-sectoral approach for the betterment of communities and operational efficiency of organizations. Using a case study of the medium size local government in the Midwest and the city’s application of sustainability planning, this article focuses on a development of an expanded definition of the bottom line and a nascent approach to measuring and tracking sustainability-related efforts. The research provides an overview of measuring sustainability adopted by this particular city, using the target-specific,extended quadruple bottom line approach. The method attempts to address economic vitality, environmental quality, social equity, and governmental accountability through governance. The use of the quadruple bottom line to measure sustainability is linked to its annual budget planning and investments in transformation-related initiatives. While such an approach to measuring sustainability progress is unique in the United States, a number of cities in Australia have also adopted the quadruple bottom line approach to measure sustainability. Lessons in reporting sustainability efforts using the quadruple bottom line, in the context of an efficient and effective service delivery, can be applied to other local governments.Journal ArticleFinal article publishe
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