• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1254-1258
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• 2003

One of the major factors that effect sensor performance is analog noise that added in a sensor signal such as voltage. In multi-axis force sensors, error sources may be classified mainly in two groups. One is structural error due to inaccuracy of sensor body. The other error source is noise signals existing in the sensed information. This paper presents a brief review about the principle of multi-axis force sensors, and then proposes a method that can reduce the effect of noise signal to sensor performance. The method is to convert analog voltage signal to digital numbers near sensor body and then to read these digital signals and conduct signal processing in the computer. By this way, we can eliminate a bad effect of electromagnetic wave emitted from computer and of 60 Hz noise emitted from AC source. The proposed method is investigated through experimental demonstration. The experimental results show that it improves S/N ratio of the sensor about 40 times in our experimental setup.

• 한국태양에너지학회 논문집
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• 제30권3호
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• pp.10-15
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• 2010

The aim of this study was to analysis the Heating/cooling performance of Solar Window System built in apartments. The solar window is the idea to integrate daylight as a third form of solar energy into a PV/Solar Collector system and allows more control due to the possibility to close the reflectors. However, there can be a conflict between the desire for on one hand daylight and view and on the other hand optimal energy conversion for the PV/Solar Collector system. The process of this study is as follows: 1) The Solar Window system is designed through the investigation of previous paper and work. 2)The simulation program(ESP-r, Therm5.0, Window6.0) was used in energy performance analysis. The reference model of simulation was made up to analysis energy performance on Solar Window system. 3)Selected reference model(Floors:15, Area of Unit:$148.5m^2$) for heating/cooling energy analysis, Energy performance simulation with various variants, such as U-value of Solar Window system according to its position and angle. Consequently, When Solar Window system is equipped with balcony window of Apartment, Annual heating and cooling energy of reference model was cut down about 5%~11%.

• 한국정밀공학회지
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• 제25권10호
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• pp.107-114
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• 2008

The aim of this study is to obtain the useful design guideline for high impulsive force device with an isolation system by the analytic approach of dynamics characteristics. In this study, the high impulsive force system was modeled and analyzed in view of multi-body dynamics, and verified the modeling and analysis result by the experiment of the high impulsive force device. Additionally, the dynamic analysis was performed for the isolation system with the selected coefficients of elastic spring and damper selected. Experimental result for the high impulsive force device with the isolation system was compared and analyzed. From the result, it was confirmed that the design guideline for the isolation system of the high impulsive force device was useful.

• 한국보육지원학회지
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• 제14권4호
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• pp.85-108
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• 2018

Objective: This study intended to analyze parenting characteristics, difficulties and support needs of multi-cultural families that had children under 3 years old, in order to develop their supporting resources. Methods: This study performed semi-structured interviews with 7 mothers from multi-cultural families that had their young children enrolled at child care and education centers in Gyeonggi Do. The interview data transcribed were analyzed using the successive contents analysis, and led to 4 themes and 12 sub-themes. Results: First, the mothers from multi-cultural families were married without understanding the Korean language and culture. Second, the multi-cultural mothers didn't properly respond to their children's needs in interaction and language aspects. As a result, the multi-cultural support centers and child care and education centers gave help to them. Third, in the view of the difficulties facing mothers, parenting problems caused by the lack of information concerning child education, the biased burden of parenting, and the different parenting values of Korean families were all expressed by the mothers. Fourth, regarding support needs, providing individual professional support for children and child-raising support for mothers, customized language and employment support for mothers and parenting education for fathers and family education on multi-culturalism are needed. Conclusion/Implications: Suggestions for decreasing the difficulties facing multi-cultural families that had children under 3 years old were discussed.

• 대한가정학회지
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• 제29권2호
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• pp.87-120
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• 1991

The purpose of this study was to identify the design characteristics of the multi-leveled chest(jang) which was the main furniture of the master bedrom(anbang) in the Chosun Dynasty. The major findings and conclusions were: 1. The front view of the multi-leveled chest were composed of a protruded top panel(kaepan), drawers, folded doors, sectional panels(chwibyok kan and morum kan) and base stand(madae) in general. Variety in the front view found more frequently in single level chests than bi- or tir-level chests. 2. The overall dimensions of each type of chest increased with increase in number of levels, but the height of the sectional parts decreased. That is, the overall proportion of the single level chests were 10 : 9, bi-level chests were 5 : 6, and tri-level chests were 2 : 3. The proportion of 1 : 1, 4 : 5, 1 : 3, 1 : 4, 1 : 5 were found often in the sectional parts such as drawers, doors, chwibyok kans and morum kans. 3. In general, the surface treatments were subtle. Carved or inlayed ornamentation were seldom seen, and most chess were finished with clear lacquer to show the natural wood grain. There were no distinctive characteristics of surface ornamentation characteristic of any one type of chest. 4. The general patterns of the metal ornaments were spade(yowidu), round, bow, rectangular(yakgua), bat and flower shapes. The multi-level chests were decorated with more metal ornament types compared with the single-level chests. 5. In conclusion, there was more variety in all the design elements in the single level chests compared with the other types of chests. The bi-and tri-level chests were quite stylized in composition, size, proportion, surface treatment, and metal ornamentation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.96-98
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• 2013

본 연구는 역대 CES에 출품된 디지털 TV의 특성을 기술의 수요곡선과 대체곡선의 관점에서 분류하여 살펴봄으로써 스마트 환경으로 진화하는 차세대 멀티미디어에 대한 예측을 제공하고자 하였다. 분석결과 초기 디지털 TV의 형태에서 기기 간 연결성(connected)을 키워드로 하는 2013년 등장한 스마트 형 디지털 TV에 이르기까지 디지털 TV는 기술 수요 곡선을 따라 진화를 거듭해왔으며, 현재 상품으로서의 수명주기의 성숙기에 이르는 것으로 나타났다. 또한 2013년 출품된 디지털 TV는 TV라는 단일 제품의 범위를 넘어서 다기능 멀티미디어 환경을 지원, 곡선형 또는 flexible 디스플레이 형태로 이미 과거의 디지털 TV의 기술 수요곡선을 넘어서 대체곡선의 도입기에 이르고 있는 것으로 나타났다.

• Journal of Communications and Networks
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• 제11권3호
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• pp.240-247
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• 2009

The results of performance analysis by adopting the channel scenarios characterized as Weibull fading for an multicarrierdirect sequence-coded division multiple access (MC-DS-CDMA) system are proposed in this investigation. On the other hand, an approximate simple expression with the criterion of bit error rate (BER) versus signal-to-noise ratio (SNR) method is derived for an MC-DS-CDMA system combining with maximal ratio combining (MRC) diversity based on the moment generating function (MGF) formula of Weibull statistics, and it associates with an alternative expression of Gaussian Q-function. Besides, the other point of view on the BER performance evaluation of an MC-DS-CDMA system is not only the assumption of both single-user and multi-user cases applied, but the phenomena of partial band interference (PBI) is also included. Moreover, in order to validate the accuracy in the derived formulas, some of the system parameters, such as Weibull fading parameter (${\beta}$), user number (K), spreading chip number (N), branch number (L), and the PBI (JSR) values, etc., are compared with each other in the numerical results. To the best of author's knowledge, it is a brand new idea which proposes the evaluation of the system performance for an MC-DS-CDMA system over the point of view with Weibull fading channel.

• 한국정보과학회논문지:소프트웨어및응용
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• 제36권10호
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• pp.836-850
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• 2009

포즈인식은 최근에 유비쿼터스 환경, 행위 예술, 로봇 제어 등에서 그 필요성이 증가되고 있는 분야로써, 컴퓨터비전, 패턴인식 등에서 활발히 연구되고 있다. 하지만 기존의 포즈인식 연구들은 사람의 회전이나 이동에 따라서 불안정한 인식률을 보인다는 단점을 갖고 있다. 이는 포즈 인식을 위해 추출한 특징이 사람의 회전, 이동 등의 다양한 변수에 영향을 크게 받기 때문이다. 이를 극복하기 위하여 본 논문에서는, 다 시점(multi-view) 환경에서의 3D Star Skeleton과 주성분 분석(principal component analysis: PCA)에 기반한 사람의 회전에 강건한 특징 추출을 제안한다. 제안된 시스템은 포즈의 특징 추출을 위해 다 시점 환경 기반의 visual hull을 생성하는 과정에서 획득 가능한 깊이 정보를 표현하는 8개의 projection map을 입력데이터로 사용한다. 이를 통해 포즈의 3D 정보를 반영하는 3D Star Skeleton을 구성하고 주성분 분석 기반의 회전에 강건한 특징을 추출한다. 실험결과에서는 다양하게 회전된 사람으로부터 생성된 3D Star Skeleton에서 특징을 추출하고 다양한 인식기를 통해 포즈인식을 해보았으며, 제안된 특징 추출 방법이 사람의 회전에 강건함을 알 수 있었다.

• Journal of Korean Neurosurgical Society
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• 제30권sup1호
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• pp.55-60
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• 2001

Objective : The purpose of the present study was to examine neurologic changes, fusion rate and degree of kyphosis from the surgical results of those patients who underwent multi-level anterior interbody fusion and internal fixation. Methods : Among 63 cases of the patients who received multi-level anterior interbody fusion and internal fixation in 5 years between 1995 to 1999 at the neurosurgery department, we performed a retrospective study in 52 cases that could be followed up with dynamic view imaging ; the results were compared and analyzed. The analysis was based on the results of history taking, physical findings and radiologic findings, and Odom criteria were used to classify those cases with neurologic changes. Results : Among those 52 cases in whom the follow-up was possible for at least a year and dynamic view imaging was possible, bone fusion was seen in 93% of the trauma cases and 95% in the non-trauma cases and overall bone fusion was observed in 94% of the cases. Bone fusion was seen in 93% of the autobone cases, 95% of the allobone cases, and 94% of the Mesh cases. Radiologic changes were observed by comparing the lateral view after surgery ; kyphosis was seen in 53% of the autobone cases, in 70% of the allobone cases, and in 35% of Mesh cases ; in 45% and 60% of the non-trauma cases and trauma cases, respectively ; and in 55% of the 2 level fusion cases and 46% of the 3 level fusion cases. Neurologic changes classified according to Odom criteria showed excellent result in 48% of all the cases, good in 23%, fair in 4%, and poor in 25%. Conclusion : Even those cases with multi-level fusion, a high fusion rate could be obtained by performing anterior interbody fusion and internal fixation ; those cases with kyphosis were related more with the presence or absence of posterior compartment injury rather than the fusion level ; and those trauma cases showed not much difference in the fusion rate compared with non-trauma cases but had a high possibility of kyphosis.

• 한국의학물리학회지:의학물리
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• 제19권4호
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• pp.256-262
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• 2008

자기공명분광법(magnetic resonance spectroscopy: MRS)은 인체내 대사물질을 정량분석하여 병변의 조기진단 및 정밀진단에 도움을 주고 있으며, 최근 임상에 이용되고 있는 자기공명분광법은 single voxel spectroscopy (SVS) 기법과 multi voxel spectroscopy (MVS) 기법이 있다. 본 연구에서는 SENSE와 NEX를 변화시킨 multi voxel spectroscopy (MVS)의 데이터와 기존 single voxel spectroscopy (SVS)의 데이터를 비교 분석하여, 각각의 데이터의 유의성 차이를 평가하고자 하였다. 정상 성인 지원자 13명(남자: 5명, 여자: 8명, 평균 41세, 표준편차 11.65세)을 대상으로 chemical shift image (CSI)를 이용한 MVS검사를 시행하였다. 장비는 3.0T Achieva Release Version 2.1 (Philips Medical System, Netherland)을 이용하였고, 8 channel head coil을 사용하여 brain thalamus 부위에서 CSI spectrum을 1 slice 획득하였다. Scan parameter로는 FOV (field of view): $230{\times}184mm^2$, TR (time to repetition): 2000 msec, TE (time to echo): 288 msec, matrix: $15{\times}12$, VOI(view of interest): $110{\times}110mm^2$, voxel size: $15{\times}15{\times}15mm^3$로 하였다. SENSE factor (S)와 NEX (N)는 S1*N1, S2*N1, S2*N2, S3*N2로 변화하여 스펙트럼을 획득하였고, 각 scan time은 5분 54초, 3분 32초, 6분 20초, 4분 20초였다. 얻은 모든 MRS 데이터는 jMRUI 3.0 Version 프로그램에서 분석하였고, SENSE factor와 NEX를 변화시켜 얻은 MVS data 그룹들이 정상 성인 뇌 대사물질의 변화에 영향을 주는지 검증하기 위해 그룹 간에 ANOVA분석을 실행하여 P 값이 0.05보다 크게 나오면 그룹들 사이에 유의한 차이가 없다고 분석하였다. NAA/Cr과 Cho/Cr의 상대적 비율은 MV와 SVS사이에서는 유의한 차이가 없었다. 즉, SENSE factor와 NEX를 변화시켜 얻은 MVS data에서 정상 성인 뇌조직의 대사물질의 변화를 관찰한 결과, S1*N1의 NAA/Cr은 $1.45{\pm}0.03$, Cho/Cr은 $0.88{\pm}0.03$이고, S2*N1의 NAA/Cr은 $1.44{\pm}0.03$, Cho/Cr은 $0.87{\pm}0.05$, S2*N2의 NAA/Cr은 $1.43{\pm}0.02$, Cho/Cr은 $0.87{\pm}0.04$이며, S3*N2의 NAA/Cr은 $1.45{\pm}0.03$, Cho/Cr은 $0.87{\pm}0.03$으로 나타났다(F-value : 1.37, D.F : 3, P-value : 0.262). 그러나 데이터의 질을 측정하기 위한 MVS 데이터의 NAA Peak line-width는 SVS 데이터의 NAA Peak line-width 보다 약 3배 정도 넓었다. 본 연구에서는 MVS에서 SENSE factor와 NEX 값을 다양하게 변화시킨 MVS의 데이터와 SVS의 데이터가 큰 차이가 없음을 확인하였다. 즉, 어는 특정 부위의 뇌 조직의 대사물질은 MVS와 SVS 기법 모두 큰 차이가 없음을 확인할 수 있었다. 그러므로 MVS는 SVS보다 광범한 부위를 짧은 시간 안에 검사할 수 있으므로 매우 유용한 방법이라고 사료된다.