• 한국산학기술학회논문지
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• 제8권3호
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• pp.556-562
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• 2007

본 논문에서는 IEEE 802.11 DCF의 성능을 향상시키기 위해 채널의 혼잡상태를 이용하여 충돌을 해결하는 방법을 제안한다. 이 기법은 혼잡 이벤트와 단일 스테이지 모델을 통해 스테이션들의 스테이지 이동 횟수를 감소시켜 무선채널에서의 충돌 발생량을 감소시킨다. 시뮬레이션을 통해 DCF, ADCF 그리고 SD 기법과 성능을 비교하였다.

• 한국통신학회논문지
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• 제14권2호
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• pp.108-120
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• 1989

본 논문에서는 저 전송에 따른 벡터 양지화의 에지 결손(edge degradation)을 줄이기 위한 새로운 방법을 제안하였다. 이 방법은 여러 개의 codebook들을 사용하며, 이 codebook들 중 하나는 현재 부호화할 벡터의 표준편차에 의해 선택되어진다. 또한 codebook을 찾는 계산량을 줄이기 위해 SD 탐색(search) 방법을 제안하였다. 결과로서 제안된 벡터 양지화기는 0.4-0.7bpp전송율에서 30dB이상의 좋은 성능을 얻었다.

• 약학회지
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• 제29권5호
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• pp.260-267
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• 1985

A gas chromatography with flame ionization detection was developed to measure tranylcypromine in rat urine. The method involves extraction of the drug and the internal standard, phenylpropylamine from the urine using ethyl acetate and back extraction into 0.5N $H_{2}SO_{4}$. Following final extraction using dichloromethane, both the drug and the internal standard were converted to trifluoroacetyl derivatives and analyzed using a column of 3% SE-30 on 80/100 mesh Chromosorb W(HP). A calibration curve was constructed in the range of $5~50{\mu}g$tranylcypromine sulfate in 0.5ml urine and found to be linear. The detection limit was $2{\mu}g$. The tranylcypromine could be analyzed with the percent recovery of $100.81{\pm}8.13$ (SD) ina concentration range of $8-40{\mu}g$ in 0.5ml urine. When 0.4mmol/kg dose of the drug was administered through, an oral route, excretion percent of tranylcypromine in rat urine over 36hr was found to be $11.90{\pm}6.04$ (SD) for tranyleypromine sulfate and $2.23{\pm}0.63$ (SD) for benzyl trans-2-phenylcyclopropanecarbamate.

• Current Optics and Photonics
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• 제7권5호
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• pp.574-581
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• 2023

A scheme is proposed to generate triangular waveforms with alterable symmetry. The key component is a cascaded single-drive Mach-Zehnder modulator (SD-MZM) and optical polarization beam splitter-combiner architecture. In this triangular waveform generator, the bias-induced phase shift, modulation index and controllable delay difference are changeable. To generate triangular waveform signals with different symmetry indexes, different combinations of these variables are selected. Compared with the previous schemes, this generator just contains one SD-MZM and the balanced photodetector (BPD) is not needed, which means the costs and energy consumption are significantly reduced. The operation principle of this triangular waveform generator has been theoretically analyzed, and the corresponding simulation is conducted. Based on the theoretical and simulated results, some experiments are demonstrated to prove the validity of the scheme. The triangular waveform signals with a symmetry factor range of 20-80% are generated. Both experiment and theory prove the feasibility of this method.

• 한국조경학회지
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• 제38권4호
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• pp.1-10
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• 2010

녹지식물과 접함으로써 얻어지는 생리 심리적 효과를 과학적으로 실증하는 것은 녹지의 심리효과에 대한 객관적인 지식의 제공과 더불어 인간의 감성을 고려한 녹지공간을 창출에 있어 유용한 근거가 될 것이다. 본 연구에서는 15명의 한국인 남성을 대상으로 자연 발산하는 소나무 잎의 향기를 맡는 동안 대뇌활동(뇌혈액동태)과 자율신경계활동(혈압, 맥박, 아밀라제)을 측정하고, SD법(Semantic Differential method)과 POMS(Profile Of Mood States)를 이용하여 소나무 향기에 대한 인상 및 감정상태의 변화를 평가하였다. 그 결과, 소나무 향기는 대뇌활동에 있어 전두야의 감정, 판단, 운동을 담당하는 부위와 측두야의 기억을 담당하는 부위의 활성화를 초래하였다. SD법과 POMS에 의한 언어적 평가에서는 소나무 향기는 자연적이지만, 자극적이고 활발한 인상을 가지며, 활기를 주고 혼란한 정서를 안정시키는 향기로서 평가되었다. 한편, 자율신경계활동에서는 유의한 차이는 보이지 않았다. 실증된 결과를 통해, 소나무 향기가 우리의 생리 심리적인 측면에 활력을 주는 사실이 과학적으로 검증되었으며, 금후 감성을 고려한 녹지환경 디자인을 위한 기초적인 자료로 활용될 것을 기대한다.

• 해양환경안전학회지
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• 제10권2호
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• pp.17-22
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• 2004

해양사고는 맡은 원인이 서로 복잡하게 상호작용을 하여 발생하고 있다. 이러한 해양사고의 분석은 선박의 안전 운항상의 측면에서 매우 중요하다고 할 수 있다. 따라서 본 연구의 목적은 시스템다이내믹스법을 이용하여 해양사고 원인과 개선책에 대한 모델을 구축하고, 요소의 개선에 대한 효과를 분석하고자 한다. 본 연구의 수행을 위해 해양사고 원인과 개선책의 요소를 브레인스토밍법에 의해 추출하고, 인과지도상의 정량적, 정성적, 피드백루프로 변환하였다. 그리고 표준모델과 4가지 정책모델에 대해 23년간(1997-2020) 시뮬레이션을 수행하였다.

• 대한인간공학회지
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• 제10권1호
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• pp.29-40
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• 1991

This study deals with a quantitative analysis of the effects of colors on learning effectiveness. First, sensuous or emotional factors that school children feel about colors of teachers' clothes are measured by SD method and analyzed by factor analysis. Second, sensuous or emotional factors to enhance learning effectiveness are measured by SD method from teachers, and principal factors are extracted by factor analysis. Finally, the analysis of interaction between the effects of colors and the learning effectiveness is done using the sensuous or emotional factors found from the previous two analyses. The results are as follows: (1) For in-class concentration, the principal factors are "stable", and "near" feelings. The colors related to these feelings are black, red, and blue. (2) For question inducing, the first principal factors are "soft" and "stable" feelings, and the colors are white and black. The second principal factors are "gentle" and "refined" feelings, and the colors are orange and black. (3) For extra-curricular activity, the principal factors are "artless" and "plain" feelings, and the color is blue.

• International journal of advanced smart convergence
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• 제13권3호
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• pp.13-17
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• 2024

The local storage method for home cameras, which relies on inserting an SD card into the device to store data, offers a convenient and cost-effective solution, as there are no recurring expenses after purchasing the SD card. However, we recognize that this method comes with significant security challenges. In particular, the ease with which third parties can access the SD card makes it vulnerable to both physical and software tampering. As the acceptance rate of home camera footage as evidence in courts has increased, we have become increasingly aware of the critical nature of these security issues. Digital data from home cameras, unlike other types of physical evidence, can be more easily tampered with and altered. To ensure that such data is recognized as valid legal evidence, we must prove its integrity and demonstrate that it has not been tampered with. In response to these challenges, we are committed to strengthening the security measures for both the home camera device and its local storage. By doing so, we aim to ensure the integrity and reliability of the data, thereby enhancing the overall security and trustworthiness of home camera systems.

• 산업공학
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• 제13권1호
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• pp.17-28
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• 2000

As knowledge has been recognized as a new resource in gaining organizational competitiveness, Knowledge Management (KM) is suggested as a method to manage and apply knowledge for business management. KM research, however, has focused on identifying, storing, and distributing the transaction-related knowledge in an organization. There has been little research on applying the knowledge to decision-making or strategy development that is the main task of business management. The application of knowledge to decision making has higher impact on organizational performance rather than just the knowledge management for process transaction. In this research, we suggest System Dynamics (SD) for the knowledge-based decision-making. Based on the modeling method of SD, we can translate partial and implicit knowledge resident in individual's mental model into organized explicit knowledge. The simulation test of the organized knowledge model enables decision-makers to understand the structure of the target problem and its behavior mechanism, which facilitates effective decision-making. We will compare the proposed method and other KM methods and discuss this research based on the application case to a real telecommunication company.

• 한국실내디자인학회논문집
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• 제13권2호
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• pp.184-191
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• 2004

The purpose of this study is to suggest designing goals and directions in the lobby area of obstetric hospitals by constructing a space evaluation structure model, which is made by image evaluation structure model used by SD method and Advanced Repertory Grid Technique. As a result of the image evaluation used by SD method, it turned out 4 factors which are related to recognizing and evaluating the space formativeness, openness, decorativeness, sensitiveness. I found out the relationship between space evaluation structure and the element of interior space. I also suggested detailed designing method based on this relationship. Space evaluation structure model can be applied to designing lobby areas of obstetric hospitals to reconstruct more specific and objective designing goals and standards rather simply designer's sensitive and abstract designing approach.