• 한국산학기술학회논문지
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• 제16권10호
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• pp.7061-7070
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• 2015

다중반응표면 최적화는 다수의 반응변수(품질특성치)를 동시에 고려하여 최적의 입력변수 조건을 찾는 반응표면분석의 세부 분야이다. 가중평균제곱오차(Weighted Mean Squared Error, WMSE) 최소화법은 평균제곱오차의 두 구성 요소인 제곱편차와 분산에 가중치를 부여한 WMSE를 활용하는데, 반응변수별로 WMSE를 구하여 이들을 종합적으로 최소화한다. 지금까지 WMSE 최소화법과 관련하여 개발된 기법은 대부분 의사결정자의 선호도 정보를 문제풀이 이전에 결정할 것을 요구하는 선호도사전제시법에 해당된다. 그러나 현실적으로 의사결정자가 자신의 선호도 정보를 사전에 정확히 제공하는 것은 매우 어렵다. 본 논문에서는 이러한 한계점을 개선하기 위하여 WMSE 최소화를 위한 선호도사후제시법을 제안한다. 제안된 방법은 의사결정자의 선호도 정보 없이 다수의 비지배적해를 생성한 후, 의사결정자가 생성된 비지배해 중 최고선호해를 선택하는 단계로 진행된다. 제안된 방법은 의사결정자로 하여금 전체 해집합의 트레이드오프 관계를 보다 폭넓은 시각으로 이해한 후 선호도 정보를 제시할 수 있도록 함으로써, 의사결정자의 선호도에 부합하는 최고선호해를 효과적으로 도출할 수 있다.

• Journal of Nutrition and Health
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• 제50권5호
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• pp.437-446
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• 2017

'계피' 건조분말 및 물추출물의 혈당 개선 기능성을 평가하기 위하여 메타 분석을 실시하였다. 2017년 5월을 기준으로 DB 검색을 통해 4,688건의 자료를 수집하여, 선정/제외 기준에 따라 선별한 결과 총 14건 (n = 709)의 연구가 분석에 포함되었다. 건조분말의 경우 하루 1~6 g씩 섭취하였을 때, 공복혈당은 -1.55 mmol/L, 식후 혈당의 곡선하면적은 $-51.8mmol/L{\cdot}min$ 수준으로, 물추출물은 하루 0.1~0.5 g씩 섭취시 공복혈당이 -0.76 mmol/L 수준으로 개선시켰으며, 당화혈색소에는 영향이 없는 것으로 분석되었다.

• 대한인간공학회지
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• 제25권2호
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• pp.119-124
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• 2006

The present study evaluated the accuracy of MSD-related work criterion of Korea Ministry of Labor by using ergonomic workload evaluation methods. 1,948 manufacturing works in automobile industry were divided into 1,286 MSD-related risky works and 662 risk-free ones by using RULA, ANSI Z-365 and perceived discomfort evaluation. Then, the two types of works were evaluated by Labor Ministry work criterion to analyze the classification accuracy of the work criterion. The work criterion of Korea Labor Ministry had low hit and false alarm ratio(20 and 11%) and high miss and correct rejection ratio(80 and 89%), and the odd ratios of hit and correct rejection were 0.2 and 8.3, respectively. It can be concluded that the work criterion of Korea Labor Ministry is a conservative evaluation method which tends to evaluate a target work as risk-free.

• Journal of Magnetics
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• 제7권3호
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• pp.80-93
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• 2002

The role of magnetic anisotropy of the antiferromagnetic layer on the magnetization process of exchange coupled polycrystalline ferromagnetidantiferromagnetic bilayers is discussed. In order to elucidate the magnetic torque response of Ni-Fe/Mn-Ir bilayers, the single spin ensemble model is newly introduced, taking into account the two-dimensionally random distribution of the magnetic anisotropy axes of the antiferromagnetic grains. The mechanism of the reversible inducement of the exchange anisotropy along desirable directions by field cooling procedure is successfully explained with the new model. Unidirectional anisotropy constant, J$k$, of polycrystalline Ni-Fe/Mn-Ir and Co-Fe/Mn-Ir bilayers is investigated as functions of the chemical composition of both the ferromagnetic layer and the antiferromagnetic layer. The effects of microstructure and surface modification of the antiferromagnetic layer on JK are also discussed. As a notable result, an extra large value of J$k$, which exceeds 0.5 erg/cm$^2$, is obtained for $Co_{70}Fe_{30}Mn_{75}Ir_{25}$ bilayer with the ultra-thin (50${\AA}$∼100${\AA}$) Mn-Ir layer. The exchange anisotropy of $Co_{70}Fe_{30}$ 40 ${\AA}/Mn_{75}Ir_{25}$ 100 ${\AA}$ bilayer is stable for thermal annealing up to $400{^{\circ}C}$, which is sufficiently high for the application of spin valve magnetoresistive devices.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.389.2-389.2
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• 2016

The flexible solid state device has been widely studied as portable and wearable device applications such as display, sensor and curved circuits. A zero-bias operation without any external power consumption is a highly-demanding feature of semiconductor devices, including optical communication, environment monitoring and digital imaging applications. Moreover, the flexibility of device would give the degree of freedom of transparent electronics. Functional and transparent abrupt p/n junction device has been realized by combining of p-type NiO and n-type ZnO metal oxide semiconductors. The use of a plastic polyethylene terephthalate (PET) film substrate spontaneously allows the flexible feature of the devices. The functional design of p-NiO/n-ZnO metal oxide device provides a high rectifying ratio of 189 to ensure the quality junction quality. This all transparent metal oxide device can be operated without external power supply. The flexible p-NiO/n-ZnO device exhibit substantial photodetection performances of quick response time of $68{\mu}s$. We may suggest an efficient design scheme of flexible and functional metal oxide-based transparent electronics.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1996년도 학술대회
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• pp.223-227
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• 1996

In this paper we propose an adaptive fast image restoration filter, which is suitable for reducing the blocking artifacts in the compressed image in real-time. The proposed restoration filter is based on the observation that quantization operation in a series of coding process is a nonlinear and many-to-one mapping operator. And then we propose an approximated version of constrained optimization technique as a restoration process for removing the nonlinear and space varying degradation operator. We also propose a novel block classification method for adaptively choosing the direction of a highpass filter, which serves as a constraint in the optimization process. The proposed classification method adopts the bias-corrected maximized likelihood, which is used to determine the number of regions in the image for the unsupervised segmentation. The proposed restoration filter can be realized either in the discrete Fourier transform domain or in the spatial domain in the form of a truncated finite impulse response (FIR) filter structure for real-time processing. In order to demonstrate the validity of the proposed restoration filter experimental results will be shown.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1132-1136
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• 2004

In this paper, we intend to make FFS mode cell with LC alignment used non-rubbing method, ion beam alignment method on the a-C:H thin film, to analyze electro-optical characteristics in this cell. We studied on the suitable inorganic thin film for FFS-LCD and the aligning capabilities of nematic liquid crystal (NLC) using the new alignment material of a-C:H thin film as working gas at rf bias condition. A high pretilt angle of about 5$^{\circ}$ by ion beam(IB) exposure on the a-C:H thin film surface was measured. An excellent voltage-transmittance (V-T) and response time curve of the ion-beam-aligned FFS-LCD was observed with oblique ion beam exposure on the DLC thin films.

• The Journal of Korean Physical Therapy
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• 제17권2호
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• pp.46-66
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• 2005

With the increase in the number of multinational and multicultural research projects, the need to adapt health status measures for use in other than source language has also grown rapidly. Most questionnaire were developed in English-speaking countries, but even within these countries, researchers must consider immigrant populations in studies of health, especially when their exclusion could lead to a systematic bias in studies of health care utilization or quality of life. The purpose of this study was to translate and and culturally adapt the three most used neck and spinal pain disability questionnaires - the Neck Disability Index(NDI), Neck pain and Disability Scale(NPDS), and Functional Rating Index(FRI) - into the korean language and evaluated their reliability, in addition to item response pattern, to achieve a good cross cultural adaptation. Each translated questionnaire was found to have high reliability (FRI ICC (2,1)=0.86 ($95\%$ CI: 0.75-0.92); NPDS ICC (2,1)=0.90 ($95\%$ CI: 0.83-0.95 ; NDI ICC (2,1) =0.90 ($95\%$ CI: 0.81-0.94)). The reliability of the translated versions of FRI, NPDS and NDI were excellent.

• 한국안전학회지
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• 제23권2호
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• pp.45-50
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• 2008

The purpose of the present study was to investigate the age difference in driving behavior(more specifically, left-turn). The participants were instructed to report whether they can turn left their car in the T-shape road(road and other vehicles' behavior relating to driver's tasks were recorded in advance and projected the simulation screen) after the leading vehicle passed them(i.e., before the target vehicle arrived). The participants' judgment accuracy and response bias were analyzed by using signal detection theory. The results showed that the old group tended to be less sensitive but more confident in their judgement of turning left their car. In particular, both age groups appeared to more depend on the distance from observation location to approaching vehicle rather than arrival times or driving speeds of the approaching vehicle.

• Industrial Engineering and Management Systems
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• 제4권2호
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• pp.176-183
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• 2005

The theory of signal detection has been applied to a wide range of practical situation for a long time, including sonar detection, air traffic control and so on. In general, in this theory, sensitivity parametric index d' and bias parametric index $\beta$ are used to evaluated the performance of vigilance. These indices use observer's response "hit" and "false alarm" to explain and evaluate vigilance, but not considering reaction time. However, the reaction time of detecting should be considered in measuring vigilance in some supervisory tasks such as unlimited monitoring tasks (e.g., supervisors in nuclear plant). There are some researchers have used the segments of reaction time to generate a pair of probabilities of hit and false alarm probabilities and plot the receiver operating characteristic curve. The purpose of this study was to develop a quantitative vigilance-measuring model by fuzzy sets, which combined the concepts of hit, false alarm and reaction time. The model extends two-values logic to multi-values logic by membership functions of fuzzy sets. A simulated experiment of monitoring task in nuclear plant was carried out. Results indicated that the new vigilance-measuring model is more efficient than traditional indices; the characteristics of vigilance would be realized more clearly in unlimited monitoring task.