• 한국군사과학기술학회지
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• 제12권1호
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• pp.8-17
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• 2009

This paper proposes robust ship wake search method in the target evasion environment. Moving surface ships generate a long trailing wake in the rear of a surface ship. Wake homing torpedo sensing this wake can detect the surface target and engage it automatically. In wake homing torpedo, wake search method is important element to maximize effectiveness of wake homing torpedo. This paper proposes one-side, two-side and centering mode according to passing wake boundary scenarios. Also, wake deflection angle is deduced by using the principle of deflection angle of acoustic torpedo. The representative experimental results using monte-carlo simulation demonstrate that the searching method using one-side mode is superior to two-side and centering mode in the target evasion environment.

• 한국음향학회지
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• 제29권3호
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• pp.155-164
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• 2010

본 논문에서는 두 개의 항적 센서를 이용한 수상함 항적 탐색 방법을 제안한다. 수상함의 항적은 수상함 후면의 수면 위에 그 이동 자취에 따라 생성된다. 본 논문에서는 항적 반향 강도가 수상함에 가까울수록 강하며 항적 탐지 센서는 항적 반향 강도를 탐지할 수 있다는 가정 아래, 항적 반향 강도를 이용한 효과적인 항적 탐색 방법을 제안하였다. 제안한 탐색 방법의 성능 평가를 위해 몬테카를로 시뮬레이션을 적용하였으며, 실험 결과 제안한 탐색 방법이 기존의 단일 항적 센서를 이용한 탐색 방법에 비해 평균 탐색 시간 측면에서 약 45초 정도의 성능 향상을 나타내었다. 또한, 항적 길이가 짧은 경우에 본 논문에서 제안한 탐색 방법이 기존의 방법에 비해 효율적임을 알 수 있었다.

• 한국IT서비스학회지
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• 제15권4호
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• pp.97-109
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• 2016

The rapid deployment of millions of mobile sensors and smart devices has resulted in high demand for opportunistic encounter-based networking. For the cooperative video surveillance of dashboard cameras in nearby vehicles, a fast and energy-efficient asynchronous neighbor discovery protocol is indispensable because a dashboard camera is an energy-hungry device after the vehicle's engine has turned off. In the existing asynchronous neighbor discovery protocols, all nodes always try to discover all neighbors. However, a dashboard camera needs to discover nearby dashboard cameras when an event is detected. In this paper, we propose a fast and energy-efficient asynchronous neighbor discovery protocol, which enables nodes : 1) to have different roles in neighbor discovery, 2) to discover neighbors within a search range, and 3) to report promptly the exact discovery result. The proposed protocol has two modes: periodic wake-up mode and active discovery mode. A node begins with the periodic wake-up mode to be discovered by other nodes, switches to the active discovery mode on receiving a neighbor discovery request, and returns to the periodic wake-up mode when the active discovery mode finishes. In the periodic wake-up mode, a node wakes up at multiples of number ${\alpha}$, where ${\alpha}$ is determined by the node's remaining battery power. In the active discovery mode, a node wakes up for consecutive ${\gamma}$ slots. Then, the node operating in the active discovery mode can discover all neighbors waking up at multiples of ${\beta}$ for ${\beta}{\leq}{\gamma}$ within ${\gamma}$ time slots. Since the proposed protocol assigns one half of the duty cycle to each mode, it consumes equal to or less energy than the existing protocols. A performance comparison shows that the proposed protocol outperforms the existing protocols in terms of discovery latency and energy consumption, where the frequency of neighbor discovery requests by car accidents is not constantly high.

• Molecules and Cells
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• 제39권1호
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• pp.53-59
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• 2016

Peroxiredoxins are cysteine-dependent peroxide reductases that group into 6 different, structurally discernable classes. In 2011, our research team reported the application of a bioinformatic approach called active site profiling to extract active site-proximal sequence segments from the 29 distinct, structurally-characterized peroxiredoxins available at the time. These extracted sequences were then used to create unique profiles for the six groups which were subsequently used to search GenBank(nr), allowing identification of ~3500 peroxiredoxin sequences and their respective subgroups. Summarized in this minireview are the features and phylogenetic distributions of each of these peroxiredoxin subgroups; an example is also provided illustrating the use of the web accessible, searchable database known as PREX to identify subfamily-specific peroxiredoxin sequences for the organism Vitis vinifera (grape).

• Archives of Plastic Surgery
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• 제48권1호
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• pp.107-113
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• 2021

Background Applicants to integrated plastic and reconstructive surgery (PRS) residency in the United States spend exorbitant amounts of time and money throughout the interview process. Outside of first-hand experience through a visiting rotation, applicants utilize various resources in learning about a program. Today's applicants are "Millennials," the demographic cohort raised during the information age and proficient with digital technology. The authors evaluated whether programs have a presence on social media, and whether applicants are following these accounts. Methods An online survey was sent to applicants to a single integrated plastic surgery program evaluating basic demographics, social media utilization, and sources of information accessed throughout the residency application process. A manual search of popular social media platforms (Instagram, Facebook, and Twitter) was performed in October 2019. Accounts affiliated with integrated PRS programs were identified and analyzed. Results Eighty-four of 222 applicants (37.8%) completed the survey. Ninety-six percent of applicants were within the Millennial demographic. Ninety-six percent of applicants had some form of social media presence, with Facebook (90%) and Instagram (87%) being the most popular platforms. Seventy-three percent of applicants reported following a PRS residency social media account. As of October 2019, 59 integrated residency programs (73%) have active Instagram accounts. Conclusions Applicants still rely on the program website when researching potential residencies, but social media is being rapidly adopted by programs. Program social media accounts should be used as a dynamic form of communication to better inform applicants of program strengths and weaknesses.

• 동의신경정신과학회지
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• 제14권1호
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• pp.175-181
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• 2003

A lot of research have been done so far in terms of traffic accident sequela, but most of them have stressed simply on physical treatments, resulting in less attention to the psychological ones. This is a case report of a patient with post-traumatic stress disorder. Although that is simply following in the wake of past therapy, we were experienced an improved case of post-traumatic stress disorder patient treated by herbal medicine, acupuncture, mental therapeutics. This case effectively describes the characteristics of the post-traumatic stress disorder, and it also suggested one approach for the treatment of the disease. This report is for the better understanding of the disease, and also the search for the advanced treatments to it hereafter.

• International Journal of Aeronautical and Space Sciences
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• 제17권3호
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• pp.285-295
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• 2016

A contact strip shape of a high speed train pantograph system was optimized with CFD to increase the aerodynamic performance and stability of contact force, and the results were validated by a wind tunnel test. For design of the optimal contact strip shape, a Kriging model and genetic algorithm were used to ensure the global search of the optimal point and reduce the computational cost. To enhance the performance and robustness of the contact strip for high speed pantograph, the drag coefficient and the fluctuation of the lift coefficient along the angle of attack were selected as design objectives. Aerodynamic forces were measured by a load cell and HWA (Hot Wire Anemometer) was used to measure the Strouhal number of wake flow. PIV (Particle Image Velocimetry) was adopted to visualize the flow fields. The optimized contact strip shape was shown a lower drag with smaller fluctuation of vertical lift force than the general shaped contact strip. And the acoustic noise source strength of the optimized contact strip was also reduced. Finally, the reduction amount of drag and noise was assessed when the optimized contact strip was applied to three dimensional pantograph system.

• 대한기계학회논문집B
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• 제30권11호
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• pp.1131-1138
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• 2006

Aerodynamic shape design of a partial admission turbine using CFD has been performed. Two step approaches are adopted in this study. Firstly, two-dimensional blade shape is optimized using CFD and genetic algorithm. Initially, the turbine cascade shape is represented by four design parameters. By controlling the design parameters as variables, the non-gradient search is analyzed for obtaining the maximum efficiency. The final two-dimensional blade proved to have a more blade power than the initial blade. Secondly, the three-dimensional CFD analysis including the nozzle, rotor and stator has been conducted. To avoid a heavy computational load due to an unsteady calculation, the frozen rotor method is implemented in steady calculation. The frozen rotor method can detect a variation of the flow-field dependent upon the blade's circumferential position relative to the nozzle. It gives a better idea of wake loss mechanism starting from the lip of the nozzle than the mixing plane concept. Finally, the combination of two and three dimensional design method of the partial admission turbine in this study has proven to be a robust tool in development phase.

• 산경연구논집
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• 제15권4호
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• pp.11-18
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• 2024

Purpose: The primary purpose of this research is to investigate the multidisciplinary effect of food delivery apps (FDAs) in urban hotels in the wake of the lockdown due to Covid-19 pandemic. Specifically, the study aims: To explore and scrutinize the primary shifts in customer behavior and preferences in modern urban hotels, and to explore and scrutinize the primary shifts in customer behavior and preferences in modern urban hotels. Research design, data and methodology: This study conducted a systematic literature review to gather evidence of the FDA's effect on customer behavior and the hospitality industry during the Covid-19 pandemic. Complying with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) principles guarantees a structured and transparent method to search the literature and its analysis. Results: The result based on the systematic review has indicated that the booming business of food delivery at home companies and changing consumer tastes prove the FDA's growing circuit in the hotel industry, thus demonstrating their ability and power to adapt to changing trends. Conclusions: Therefore, this study concludes that using FDA's platform, future hospitality managers have to focus on agility in operations, innovation, and technology integration to keep up with changing consumer trends and market conditions.

• 대한감각통합치료학회지
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• 제21권2호
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• pp.69-83
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• 2023

목적 : 본 연구는 수면장애 아동을 대상으로 사회적 이야기(social story)를 적용한 연구를 대상으로 중재효과를 체계적으로 고찰하고자 하였다. 연구방법 : 본 연구는 2001년에서 2022년까지 데이터베이스 Scopus, ScienceDirect, psycArticles, Pubmed에 게재된 문헌들을 대상으로 하였다. 검색어는 'social story' OR 'social stories' AND 'sleep' OR 'sleep disorders' OR 'sleep wake disorder bedtimes' OR 'sleep initiation' and 'maintenance disorders' OR 'sleep wake disorder' OR 'sleep arousal disorder'을 사용하였다. 선정 기준에 따라 최종적으로 6편의 실험연구를 선정하여 분석을 실시하였다. 결과 : 분석 대상 문헌은 무작위 대조 실험연구는 2편, 개별 실험연구가 3편, 사례연구가 1편이었다. 대상자는 진단별로는 자폐스펙트럼 아동, 연령별로는 학령기와 청소년기가 가장 많았다. 중재유형은 사회적 이야기와 다른 중재를 함께 포함한 복합중재가 많았고, 중재 기간은 1일부터 40일 이상으로 다양하였다. 중재 효과로는 수면의 질에 긍정적인 효과를 보였으며, 그중에서도 야간 각성(night walking), 수면 시작 지연(sleep onset delay), 수면 불안(sleep anxiety)이 개선되었다. 사회적 이야기의 효과를 평가하는 도구로는 표준화된 평가에서는 아동 수면 습관 설문지(children's sleep habits questionnaire)와 아동 행동 체크리스트(child behavior checklist)를 가장 많이 사용하였고, 비표준화된 평가로는 인터뷰(interview), 수면일기 (Sleep diary)를 사용한 연구가 많았다. 결론 : 본 연구는 수면장애가 있는 아동 및 청소년에게 사회적 이야기를 적용함으로써 임상에서 적용할 수 있는 수면 중재 방향을 모색하는 것에 의의가 있다. 사회적 이야기의 중재 효과로는 야간 각성(night wakings), 수면 시작 지연(sleep onset delay), 수면 불안(sleep anxiety) 영역이 개선된 연구들이 큰 비중을 차지하였다. 수면의 질의 세부 효과 영역은 대부분의 연구에서 중재 전후 유의한 개선을 나타냈으며, 본 연구에서 분석한 6편의 연구에서는 추적검사를 통해서 중재 효과에 대한 지속을 확인할 수 있었다. 따라서 본 연구는 사회적 이야기(social story)를 적용한 수면장애 아동의 중재 효과, 결과 평가 도구, 중재 기간을 제시함으로써 수면장애 아동을 대상으로 사회적 이야기(social story)를 임상에서 적용할 때 도움이 될 것으로 판단된다.