• Communications for Statistical Applications and Methods
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• 제24권2호
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• pp.173-191
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• 2017

This study develops a new type of latent class analysis (LCA) in order to explain the associations between one latent variable and several other categorical latent variables. Our model postulates that the prevalence of the latent variable of interest is affected by another latent variable composed of other several latent variables. For the parameter estimation, we propose deterministic annealing EM (DAEM) to deal with local maxima problem in the proposed model. We perform simulation study to demonstrate how DAEM can find the set of parameter estimates at the global maximum of the likelihood over the repeated samples. We apply the proposed LCA model in an investigation of the effect of and joint patterns for drug-using behavior to violent behavior among US high school male students using data from the Youth Risk Behavior Surveillance System 2015. Considering the age of male adolescents as a covariate influencing violent behavior, we identified three classes of violent behavior and three classes of drug-using behavior. We also discovered that the prevalence of violent behavior is affected by the type of drug used for drug-using behavior.

• 제어로봇시스템학회논문지
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• 제14권6호
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• pp.608-614
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• 2008

This paper describes a location tracking system to guide landing process of an Unmanned Helicopter(UMH) exploiting MIT Cricket nodes. For automatic landing of a UMH, a precise positioning system is indispensable. However, GPS(Global Positioning System) is inadequate for tracking the three dimensional position of a UMH because of large positioning errors. The Cricket systems use Time-Difference-of-Arrival(TDoA) method with ultrasonic and RF(Radio Frequency) signals to measure distances. They operate in passive mode in that a listener attached to a moving device receives distance signals from several beacons located at fixed points on ground. Inevitably, this passive type of implementation causes large disturbances in measuring distances between beacons and the listener due to wind blow from propeller and turbulence of UMH body. To cope with this problem, we proposed active type of implementation for positioning a UMH. In this implementation, a beacon is set up at UMH body and four listeners are located at ground area at least where the UMH will land. A pair of Ultrasonic and RF signals from the beacon arrives at several listeners to calculate the position of the UMH. The distance signals among listeners are synchronized with a counter value appended to each distance signals from the beacon.

• 조명전기설비학회논문지
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• 제28권12호
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• pp.95-102
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• 2014

This paper proposes a coordinated control for an independent multi-phase transverse flux linear synchronous motor (IM-TFLSM) based on magnetic levitation. The stator structures of the IM-TFLSM are composed of a two set, which has independent three-phase windings and a double-sided air-gap as opposed to the conventional Y-connected three-phase linear motors. A suitable control algorithm is necessary to operate the applied linear machine. This study proposes a coordinated control algorithm for adjusting the mover air-gap and thrust force of the IM-TFLSM in order to maintain air-gap and phase shifted current control of the independent 3-phase modules. In addition, the principle of operation and its special structures are described in detail and the validity and effectiveness of the control algorithm is verified through multiple experimental results.

• 한국콘텐츠학회논문지
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• 제17권12호
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• pp.236-246
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• 2017

본 연구는 스타 셰프의 쿡방 출연에 대한 조리사의 주관적 인식에 관한 연구로 호텔 및 레스토랑에 조리사를 대상으로 주관적인 경향을 알아보기 위해 Q방법론을 적용하여 분석하였다. 이 논문의 연구 문제는 크게 3가지로, 연구문제 1 : 스타 셰프의 쿡방 출연에 관한 조리사의 주관적 인식의 수용 형태는 어떠한가?, 연구문제 2 : 스타 셰프의 쿡방 출연에 관한 조리사의 주관적 인식의 동질적 유형의 특성은 어떠한가?, 연구문제 3 : 스타 셰프의 쿡방 출연에 관한 조리사의 주관적 인식의 유형별 공통점과 차이점은 무엇인가? 이다. 이러한 연구문제를 기반으로 하여 유형 분석결과 4가지 유형으로 도출되었다. 구체적으로, 제 1유형(N=8) : 쿡방을 통한 전문지식 습득형 (Acquiring expertise through cooking broadcast type), 제 2유형 (N=10) : 새로운 방송 장르 인식형 (New Broadcast Genre Recognition Type), 제 3유형 (N=2) : 셰프의 직업현실 인지형(The profession of the chef reality recognition type), 제 4유형(N=2) : 셰프의 직업 이미지 상승효과형 (Profession image of chef Synergy type) 으로, 각 각 독특한 특징의 유형으로 분석되었다.

• 한국의류산업학회지
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• 제10권5호
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• pp.652-659
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• 2008

This study was designed to testify the possibility and devise the method to manipulate the 3D body scan data to produce rounded-belt pattern adaptable to hip-type variation of women in their 20's. The results of this research were as follows : Firstly, based on drop-value distribution of hip and waist girth, 151 subjects were classified into three hip-types; Type 1 (15.23%) was 'cylinder type', showing lowest drop-value, Type 2 (69.54%) was 'average type' and Type3 (15.23%) was 'hourglass type' showing highest drop-value. Secondly, using CAD program, design lines for round shape belt were set on the surface of 3D scan data of representative subject of each type. And divided 3D surfaces were flattened onto the plane by the internal tools of CAD program. The measure, 'lifting value of round belt pattern', implying the level of curve ratio of pattern was higher in back than front. This result might be linked to the fact that the hip part is more protruded than the abdomen part. And the measures also showed highest values in Type 3(hourglass type) and lowest in Type 1(cylinder type), meaning that the pattern of Type 3 showed more rounded shape than that of Type 1. This finding implied that round belt for body type having high drop-value should be shaped more curved. Thirdly, difference ratios of outline length and area between 3D curves(body surface) and 2D plane(pattern) were 4.5% and 1.3%, respectively. This result demonstrated and solidified the feasibility of designing digital garment pattern from 3D body scan data.

• 한국정밀공학회지
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• 제25권8호
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• pp.21-28
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• 2008

Fizeau interferometer is used for inspecting the lens surface profile accurately. This study is focused on the design and optical measuring techniques for large optical components, such as a reflection mirror for large area lithography or astronomical purpose. A tower type Fizeau interferometer is designed and set up in horizontally with a 45$^{\circ}$ fold mirror which makes easy to align the optical path of heavy interferometer system. To align the optical path, a five-axes stage for the interferometer is required. This study shows a method of the 45$^{\circ}$ fold mirror alignment by using a three-axis stage instead of adjusting the interferometer itself or measuring object. This system will be installed on the large optics polishing machine during the manufacturing process as an on-machine inspection system.

• 한국유체기계학회 논문집
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• 제10권1호
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• pp.49-55
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• 2007

An 'Y' strainer type automatic flow rate regulating valve, which functions are to remove impurities from hot water inside the pipe and to maintain a constant flow rate regardless of variations of the differential pressure between valve inlet and outlet at the same time, is developed for distributing hot water equally to several pipes with district heating or central heating system. Numerical analysis of the three dimensional turbulent flow field in a valve shape is carried out to confirm the flow field whether the designed regulator shape is acceptable or not. The final developed valve improves installation time and cost and maintenance ability comparing with set-up 'Y' strainer and regulator separately. Tolerance for the nominal flow rate is also satisfied within ${\pm}5%$.

• 한국전산응용수학회:학술대회논문집
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• 한국전산응용수학회 2003년도 KSCAM 학술발표회 프로그램 및 초록집
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• pp.16.1-16
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• 2003

A subset S of vertices of a graph G is independent if no two vertices of S are adjacent by an edge in G. Also we say that S is maximal independent if it is contained In no larger independent set in G. A planted plane tree is a tree that is embedded in the plane and rooted at an end-vertex. A (k＋1) -valent tree is a planted plane tree in which each vertex has degree one or (k＋1). We classify maximal independent sets of (k＋1) -valent trees into two groups, namely, type A and type B maximal independent sets and consider specific independent sets of these trees. We study relations among these three types of independent sets. Using the relations, we count the number of all maximal independent sets of (k＋1) -valent trees with n vertices of degree (k＋1).

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.595-602
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• 2015

The rotor configuration of the brushless doubly fed induction generator (BDFIG) plays an important role in its performance. In order to make the magnetomotive force (MMF) space vector in one set rotor windings to couple both magnetic fields with different pole-pair and have low resistance and inductance, this paper presents a novel wound rotor type for BDFIG with low space harmonic contents. In accordance with the principles of slot MMF harmonics and unequal element coils, this novel rotor winding is designed to be composed of three-layer unequal-pitch unequal-turn coils. The optimal design process and rules are given in detail with an example. The performance of a 700kW 2/4 pole-pair prototype with the proposed wound rotor is analyzed by the finite element simulation and experimental test, which are also carried out to verify the effectiveness of the proposed wound rotor configuration.

• 한국의류학회지
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• 제21권2호
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• pp.251-261
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• 1997

According to consumer's washing behavior, the washing efficiency of three different types of washing machines-pulsator, agitator, and drum was studied. Their detergency, rinsing efficiency, and the degree of fabric damage, tangle, and wrinkle were evaluated. The results showed that efficient washing capacity was different from the specified capacity of washing machine. Detergency and rinsing efficiency frere apparently decreased when more than 50% of capacity was loaded in washing machine of pulsator type, and 80% for agitator or drum types. They were also affected by detergent adding methods, and decreased in the order of water-detergent-washing load> washing load-detergent-water> washing load-water-detergent. Rinsing efficiency was significantly improved when the rinsing temperature was set above washing temperature. In addition, it was revealed that detergency, fabric damage, wrinkle, and tangle were highly correlated. The relationships between detergency and tangle were different for different types of washing machine. Positive relationships were found for agitator and drum types, whereas negative for pulsator type.