141 research outputs found
An effective fault aware test case prioritization by incorporating a fault localization technique
No full textPrior coverage-based test case prioritization techniques aim to increase fault detection rates by ordering the test cases according to some coverage criteria. However, in practice, since detected faults are typically removed, test cases that already covered the previously executed areas might not perform well as expected, irrespective of their coverage. In this case, the ordering of test cases based on coverage information might not be effective. In this paper, we introduce a new test case prioritization technique that considers both coverage and historical fault information by incorporating fault localization technique. Using the historical fault detection information of test cases, our approach adjusts the priorities of fault-found test cases while maintaining test cases with high coverage in high priority. Our approach can reduce the total cost of executing entire test suite(s) and enables to detect faults earlier in a testing process by improving the testing effectiveness compared to the prior coverage-based techniques
Quantitative project management framework via integrating
No full textProcess technologies such as Personal Software ProcessSM (PSP) and Team Software ProcessSM (TSP) provide a good foundation for Six Sigma applications in business. Business approaches using Six Sigma provide methods for process improvement and analysis to achieve the goals of the PSP/TSP. This article discusses a framework with which software engineers and project managers can quantitatively manage software projects for improving the processes by applying Six Sigma in conjunction with PSP/TSP
Infinite Dimensional Holomorphic Homogeneous Regular Domains (vol 30, pg 223, 2020)
No full textWe correct an error in Lemma 2.3 in our paper with the above title, published in J. Geom. Anal. 30: 223–247.11Nsciescopu
Sports injury and illness incidence among South Korean elite athletes in the 2018 Asian Games: a single-physician prospective study of 782 athletes
No full textObjective The increasing incidence of sports injury among athletes calls for systemic surveillance of injuries and illnesses in this field to develop preventive measures. The patterns of injuries and illnesses that occurred among Korean athletes during the 2018 Asian Games held in Indonesia were studied.Methods We recorded the occurrence of all injuries and illnesses reported to the chief medical officer, coordinated with the help of an instant social messaging application in real time.Results A total of 782 elite athletes participated in 46 sporting events. A total of 141 (18.03%) injuries were recorded, with 121 (15.47%) athletes suffering at least one injury. Out of 141 injuries 80 (56.74%) were in male athletes and 61 (43.26%) were in female athletes. The highest number of injuries was seen among sport climbing athletes (n=10, 71.43%), followed by sepak takraw. A total of 16 (11.35%) injuries were expected to prevent athletes from participation in competition/training. Most of the injuries occurred during training (46.10%), with lower lumbar spine being the most common part injured. A total of 209 (26.72%) illnesses were reported, with at least one illness in 170 (21.73%) athletes. The incidence among female athletes (26.90%) was comparable with that of male athletes (26.90%). Maximum illness rate was reported in table tennis (100%). The most common system involved was gastrointestinal (n=93, 44.49%), followed by respiratory (n=53, 25.36%). Environmental factors were causative in 111 athletes (53.11%) and infection in 79 (37.79%). Illnesses resulted in loss of at least 1 day among 30 (14.35%) athletes.Conclusion Overall 15.47% of athletes suffered at least one injury and 21.73% suffered at least one illness; the incidence of injury and illness varied depending on the type of sports
Excited-state reaction dynamics of the radical anions revealed by time-resolved photofragment depletion spectroscopy
No full textThe excited-state reaction dynamics of radical anions are investigated using a newly developed technique: time-resolved photofragment depletion spectroscopy. This method leverages differences in photodetachment cross-sections among transient anionic species involved in the reaction pathway. It offers a distinct advantage for studying radical anions, which are typically challenging to probe using conventional spectroscopic techniques due to their low electron affinities. As a benchmark, the method is first applied to I-2(-), whose excited-state behavior is well characterized. The technique is then extended to CH3NO2- and (CH3NO2)(2)(-), enabling real-time probing of the excited-state dynamics of their nonvalence-bound states. Our findings reveal that ultrafast internal conversion from a nonvalence orbital to a valence orbital is followed either by prompt chemical bond dissociation or by comparatively slower cluster decomposition. These results highlight the dynamic role of the nonvalence orbital in driving chemical reactivity.
Experimental study on soil breakout force of sunken ships
No full text학위논문(석사) -- 서울대학교대학원 : 공과대학 조선해양공학과, 2023. 8. 남보우.선박의 침몰사고는 인명피해는 물론, 침몰선의 유류 및 기타 오염물질의 유출로 인한 해양오염 등 다양한 2차 사고로 이어질 수 있기 때문에, 신속한 구난 및 인양 작업이 요구된다. 해저면에 침몰된 선박의 인양작업은 침몰선의 해저면 이탈, 수중 인양, 자유수면 통과, 공기 중 인양 단계들로 구분될 수 있으며, 이 중 첫 번째 단계인 해저면 이탈을 안전하게 수행하기 위해서는 적절한 해저면 이탈력을 예측하는 것이 중요하다.
해저면 이탈력은 물체가 해저면을 이탈할 때 해저 저질에 의해 작용하는 힘으로 인양력을 구성하는 주요 성분 중 하나이다. 해저면 이탈력을 평가하기 위하여 Lee(1972)가 제안한 해저면 이탈력 추정식이 가장 널리 활용되고 있으며, 해당 해저면 이탈력 추정식은 단순형상 구조물에 대한 실해역 및 모형실험 데이터를 기반으로 개발되었다. 반면 본 연구에서 고려하고 있는 복잡한 3차원 형상의 선박에 대한 직접적인 적용 가능성에 대해서는 추가적인 검토가 필요하다.
이에 본 연구에서는 침몰선의 해저면 이탈력을 평가할 수 있는 추정식을 개발하고자 일련의 모형실험을 수행하였다. 첫째, 본 연구에서는 대한민국 연안의 해저 저질을 이용하여 다양한 단순형상 구조물에 대한 해저면 이탈력 모형실험을 수행하고, 그 물리적인 특성과 기존의 해저면 이탈력 추정식의 정확도에 대해 검토하였다. 둘째, 선박 형상 구조물에 대한 해저면 이탈력 모형실험을 수행하고, Lee(1972) 추정식에 형상계수를 도입하여 선박 형상에 적용 가능한 수정된 해저면 이탈력 추정식을 제안하였다. 셋째, 다양한 인양작업에서 발생할 수 있는 선박의 침몰 자세와 인양 속도에 대한 추가적인 모형실험을 수행하고, 그 영향에 대해 검토하였다.Ship sinking accidents can lead to various secondary accidents, for instance, loss of life, marine pollution caused by the leakage of fuel and other pollutants from the sunken ship, thus emergency rescue and salvage operations are essential. The salvage operation of a sunken ship submerged on the seabed can be categorized into several stages: breakout from the seabed, underwater lifting, surfacing, and aerial lifting. Among them, predicting the appropriate bottom breakout force is crucial for safely performing the first stage, the breakout from the seabed.
The bottom breakout force is one of the main components of the lifting force, which acts due to the resistance of the seabed when an object breakout from it. The most widely used method to evaluate the bottom breakout force is the bottom breakout force estimation formula proposed by Lee (1972). This bottom breakout force estimation formula is based on experimental results conducted with simple shaped structures. However, an examination of its direct applicability to ships, which have relatively complex three-dimensional shapes, is needed.
In this study, a series of experiments are conducted with the aim of developing a formula for the bottom breakout force of sunken ships.
First, experiments on the bottom breakout force for various simple-shaped structures using the seabed soil of South Korea's coastal area are conducted. Also, the examination of their physical characteristics and the accuracy of the existing bottom breakout force estimation formula is conducted.
Second, experiments on the bottom breakout force for ship-shaped structures are conducted, and a modified bottom breakout force estimation formula, which introduces a shape factor to the Lee(1972)s formula, is proposed for applicability to ship shapes.
Third, additional experiments are conducted on the sinking posture of the ship and the lifting speed that can occur in various salvage operations, and their effects are examined.제 1 장 서 론 1
제 1 절 연구 배경 1
제 2 절 연구 사례 3
제 3 절 연구 목표 및 연구 내용 9
제 2 장 연구 방법 10
제 1 절 모형실험 설비 10
제 2 절 실험 시료 12
제 3 절 실험 모델 14
제 4 절 신호 처리 18
제 5 절 인양 케이블의 선정 20
제 3 장 모형실험 23
제 1 절 단순형상 구조물 23
제 2 절 선박형상 구조물 28
제 3 절 모형실험의 분산성 31
제 4 장 결과분석 및 논의 35
제 1 절 물체의 형상의 영향 35
제 2 절 침몰 자세의 영향 40
제 3 절 해저 저질의 영향 43
제 4 절 인양 속도의 영향 48
제 5 절 침몰 시간의 영향 52
제 5 장 요약 및 결론 55
참고문헌 57
Abstract 60석
A 25.78125Gbps Bi-directional Transceiver with Framed-Pulsewidth Modulation (FPWM) for Extended Reach Optical Links in 28nm CMOS
No full textWe report 25.78125Gb/s time-based modulation scheme referred to as FPWM that extends the reach of C-band optical links by more than 20km as compared to NRZ. The FPWM is insensitive to component nonlinearity since only two signal levels are used unlike PAM4. Measurements show that FPWM achieves 6dB SNR gain over PAM4 in back-to-back and 8dB gain over NRZ at 15km
Novel approaches to clustering, biclustering algorithms based on adaptive resonance theory and intelligent control
No full textThe problem of clustering is one of the most widely studied area in data mining and machine learning. Adaptive resonance theory (ART), an unsupervised learning clustering algorithm, is a clustering method that can learn arbitrary input patterns in a stable, fast and self-organizing way. This dissertation focuses on unsupervised learning methods, mostly based on variations of ART.
Hierarchical ART clustering is studied by generating a tree of ART units with GPU based parallelization to provide fast and finesse clustering. Experiment results show that the our method achieves significant training speed increase in generating deep ART trees compared with that from non-parallelized version.
In order to handle high dimensional, noisy data more accurately, a hierarchical biclustering ARTMAP (H-BARTMAP) is developed. The nature of biclustering, which considers the correlation of each members in clusters, combined with the concept of hierarchical clustering, provides highly accurate experimental results, especially in bioinformatics data sets.
The third paper focuses on applying the biclustering concept to a supervised learning method, named supervised BARTMAP (S-BARTMAP). Experimental results on high dimensional data sets show that S-BARTMAP is capable of making better predictions compared with those from other math based and machine learning methods
The final paper focuses on solving the semi-supervised support vector machine (S3VM) optimization problem with the aid of value gradient learning (VGL). By applying a reinforcement learning method to a semi-supervised problem results in a solid classification performance in terms of cluster validation, better than algorithms from previous studies --Abstract, page iv
라디칼 음이온의 시분해 광탈착 및 광분해 반응동역학 연구
No full text학위논문(박사) - 한국과학기술원 : 화학과, 2024.2,[vi, 97 p. :]Radical anions, formed by attaching electrons to stable molecules, are gaining attention as pivotal role in controlling chemical reactions with excess electrons due to their diverse chemical activities. Moreover, the excited states of radical anions in the anion formation reactions hold the key to the creation and destruction of the anion. However, despite various spectroscopic experiments conducted over half a century, the reaction dynamics of radical anions remain enigmatic. Experimental techniques applied to neutral molecules or deprotonated anions often proved inadequate for radical anions, and phenomena occurring in their excited states were limitedly studied due to experimental constraints. In this thesis, we aim to introduce newly developed experimental techniques for radical anion research. Additionally, we present novel experimental findings and their interpretations. Through the experiments, the presence of multiple non-valence bound states in the anion was discovered, and by leveraging femtosecond lasers, we successfully observed chemical reactions occurring in real-time from these states.한국과학기술원 :화학과
Femtosecond real-time fragmentation dynamics of the nitrobenzene anion reveal the dissociative electron attachment mechanism
No full textThe femtosecond real-time dynamics of the nitrobenzene anion (C6H5NO2-) in the excited state have been investigated using a recently developed time-resolved photofragment depletion (TRPD) spectroscopic technique, providing molecular-level insight into the C-N bond dissociation pathway leading to (center dot)C6H5 and NO2- fragments for the first time. Ultrafast electronic relaxation from the D2 state, prepared at 2.48 eV, to the ground state (D0) is followed by statistical unimolecular dissociation, yielding NO2- with a lifetime (tau) of approximately 294 ps. This behavior stands in stark contrast to the prompt bond rupture typically observed in conventional dissociative electron attachment (DEA) processes, offering deep insight into the energy flow that governs anionic bond dissociation following electron-molecule collisions.
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