• 한국콘텐츠학회논문지
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• 제6권4호
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• pp.11-18
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• 2006

본 논문에서는 두 가지 새로운 임펄스 잡음 검출기를 설계하고 총변량(total variation) 최적화를 통하여 영상에 존재하는 임펄스 잡음을 제거하는 방법을 제안한다. 설계된 임펄스 잡음 검출기는 적응 미디언 필터(AMF:Adaptive Median Filter)를 기반으로 하고 있으며 기존의 검출기에 비해 잡음검출의 정확도가 높고 영상의 디테일 정보를 잡음으로 오인하는 확률을 줄였다. 또한 제안하는 검출기는 잡음발생 확률에 무관하게 우수한 성능을 유지한다. 영상에서의 잡음제거는 제안된 검출기에 의해 얻어진 잡음후보 화소에 대해서만 총변량 최적화를 적용하므로 불필요한 계산을 줄이고 영상의 경계선을 잘 보존하면서 잡음을 제거할 수 있다. 실험결과 제안하는 2단 구조의 잡음제거 알고리즘은 다양한 형태의 잡음 밀도에 대해서 기존의 알고리즘에 비해 약 2dB 정도의 화질개선 효과를 얻었다.

• 복식문화연구
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• 제16권1호
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• pp.166-180
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• 2008

These days, sexual harassment in the workplace or at school is being socially visualized. In this study, the desirable direction for clothing behavior is suggested by discussing the relationship between sexual desire and clothing. The relationship between sexual impulse and clothing is provided by studying college student's general opinion about sexual desire, also different ideas from females and males about the clothes that cause sexual impulses were studied, moreover, the desirable direction for clothing behavior is suggested by comparing the perceptions of college students about overly revealing clothing. This study performed the self description method and in-depth interview method on male and female college students at 3 University for 3 weeks from May, 28, 2007 to June, 23, 2007. After which 564 survey papers were distributed. The program SPSS WIN 12.0 was used to statistically analyze the data Frequency analysis, cross analysis, T-test, and a reliability test were performed on the study subject. According to the study results, sexual impulses are affected not only by internal factors but also external factors such as clothing and it is an important point. Women should not only pursue an attractive external appearance but also consider how other people think and respond to the message, and they should protect themselves from sexual harassment, or sexual violence, which are anti-social behaviors, by wearing clothes that are less stimulating.

• 한국강구조학회 논문집
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• 제28권4호
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• pp.271-280
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• 2016

근접거리에서의 폭발하중의 정확한 정량화에 대한 요구는 주요기반시설물, 빌딩 및 교량의 안전설계가 근접폭발에 대한 것이라는 점에서 매우 중요하다. 근접폭발에 대한 입사 및 반사압력은 높은 압력과 온도로 인하여 사용가능한 압력변환기로는 직접적인 측정이 매우 힘들며, 이는 근접거리에서의 압력과 충격량에 대한 합당한 예측을 가능하게 하는 확인되고 검증된 전산유체역학코드를 필요로 한다. 본 논문은 입사 및 반사 초과압력 및 충격량의 산정에 대하여 CFD 코드를 확인하고 증명하기 위한 수치해석에 대하여 소개하였다. 연구는 근접거리에 초점을 맞추어 수행되었으며, 근접폭발 시뮬레이션을 최적화하는 메쉬크기에 대에 대해서도 제안하였다.

• ETRI Journal
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• 제34권2호
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• pp.175-183
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• 2012

Conventional synchronization algorithms for impulse radio require high-speed sampling and a precise local clock. Here, a phase-locked loop (PLL) scheme is introduced to acquire and track periodical impulses. The proposed impulse PLL (iPLL) is analyzed under an ideal Gaussian noise channel and multipath environment. The timing synchronization can be recovered directly from the locked frequency and phase. To make full use of the high harmonics of the received impulses efficiently in synchronization, the switching phase detector is applied in iPLL. It is capable of obtaining higher loop gain without a rise in timing errors. In different environments, simulations verify our analysis and show about one-tenth of the root mean square errors of conventional impulse synchronizations. The developed iPLL prototype applied in a high-speed ultra-wideband transceiver shows its feasibility, low complexity, and high precision.

• 한국운동역학회지
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• 제23권2호
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• pp.131-139
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• 2013

Naejirgi is one of the fastest, most forceful and most often being used kicks in Taekkyon games, The purpose of this study was to investigate kinetic factors on two types of Naejirgi kick, one of which uses knee bending of supporting leg and the other uses little it. 12 taekkyoners (11 males and one female) who are the students of Y University participated in this study. They have been practicing on Taekkyon for five years or more. Positions of CoM, the elapsed time of each phase, vertical ground reaction forces, joint moments and impulses of supporting leg were analyzed for this study. The results were as follows; in Naejirgi with knee bending of supporting leg than without knee bending of supporting leg, the vertical motion range of whole body CoM was larger during phase 2 and 3, the elapsed time of phase 4 were longer, players stayed longer in the nearest location to opponent, during phase 4 the vertical ground reaction forces of supporting foot were larger, and joint extension moments and angular impulses of supporting leg (especially knee) were larger. In conclusion supporting knee bending is not a useful strategy for Naejirgi, because players stay longer in the nearest position to opponent and consumed more muscle force and energy for producing the vertical momentum which is unnecessary for pushing down the opponent.

• 정보보호학회논문지
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• 제6권4호
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• pp.3-38
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• 1996

The mobile station shall convolutionally encode the data transmitted on the reverse traffic channel and the access channel prior to interleaving. Code symbols output from the convolutional encoder are repeated before being interleaved except the 9600 bps data rate. All the symbols are then interleaved, 64-ary orthogonal modulation, direct-sequence spreading, quadrature spreading, baseband filtering and QPSK transmission. The sync, paging, and forward traffic channel except the pilot channel in the forward CDMA channel are convolutionally encoded, block interleaved, spread with Walsh function at a fixed chip rate of 1.2288 Mcps to provide orthogonal channelization among all code channels. Following the spreading operation, the I and Q impulses are applied to respective baseband filters. After that, these impulses shall be transmitted by QPSK. Authentication in the CDMA system is the process for confirming the identity of the mobile station by exchanging information between a mobile station and the base station. The authentication scheme is to generate a 18-bit hash code from the 152-bit message length appended with 24-bit or 40-bit padding. Several techniques are proposed for the authentication data computation in this paper. To protect sensitive subscriber information, it shall be required enciphering ceratin fields of selected traffic channel signaling messages. The message encryption can be accomplished in two ways, i.e., external encryption and internal encryption.

• 로봇학회논문지
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• 제18권1호
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• pp.127-134
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• 2023

Recently, various input shapers have been introduced to reduce residual vibrations of flexible robots. However, there have been no studies on the design of an input shaper that can suppress residual vibration at an arbitrarily specified duration. In this paper, a novel input shaper called an SD (specified-duration) shaper is proposed for an undamped or underdamped system, which can suppress residual vibration at an arbitrarily given specified duration. If the specified duration is larger than a half period, a positive SD shaper composed of all positive impulses is designed, and if the specified duration is smaller than a half period, a negative SD shaper including a negative impulse is designed. As the specified duration is increased every half period after a half period, the number of impulses of the positive SD shaper is increased one by one, and the robustness of the SD shaper to modeling errors is increased. The performance of the SD shaper is analyzed through simulation studies for an undamped and underdamped second-order systems. The validity of the SD shapers is demonstrated experimentally using an experimental device that can generate container transport motions.

• Journal of Preventive Medicine and Public Health
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• 제42권2호
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• pp.82-88
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• 2009

Objectives : Our objective was to examine and evaluate the psychological health of the residents of Taean during the cleanup of the Hebei Spirit(HS) oil spill and to review some factors associated with the results. Methods : A community survey of 71 men and women was conducted 8 weeks after the HS oil spill. Questionnaires used were the PWI(Psychological Well-being Index) scale for psychosocial distress, the CES-D(Center for Epidemiologic Studies-Depression) scale for depressive symptoms, and a questionnaire created to assess suicidal impulses. Results : The overall prevalence of high-risk psychosocial distress among the study group was 64.2%. The percentages of respondents with scores on the CES-D Scale above 16 and above 21 were 77.6% and 62.7%, respectively. The percentage of respondents categorized as having suicidal impulses was 18.3%. When compared with unexposed groups in the general population taken from various sources, the residents of Taean were 6.5 times as likely to have high stress and 9.4-9.7 times as likely to be depressed. No significant difference in the rate of suicidal impulse was found between the residents of Taean and the general population. Factors associated with high stress, depression, and suicidal impulses were age, a change in income, educational level, number of days working on the cleanup, and positive responses to questions about "affected daily activity" and "hospital visit due to work on cleanup". Conclusions : The results suggest that the HS oil spill had a significant impact on the psychological health of residents of Taean, but the comparability of the unexposed groups is a limitation of the study.

• Journal of applied mathematics & informatics
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• 제30권3_4호
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• pp.429-444
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• 2012

By using Mawhin continuation theorem and comparison theorem, the existence of periodic solution and persistence for a predator-prey system with diffusion and impulses are investigated in this paper. An example and simulation are given to show the effectiveness of the main results.

• Journal of applied mathematics & informatics
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• 제29권5_6호
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• pp.1327-1335
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• 2011

This paper demonstrates that there is a unique exponentially stable equilibrium state of a class of impulsive cellular neural network with delays. The analysis exploits M-matrix theory and generalized comparison principle to derive some easily verifiable sufficient conditions for the global exponential stability of the equilibrium state. The results extend and improve earlier publications. An example with its simulation is given for illustration of theoretical results.