• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.965-967
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• 1993

In this paper, Take two perment magnets and three iron bars and wind copper wire around one or the bars. This paper demonstrate that the method or calculation yields the right results with MAXWELL-2D program package for computing magnetic field, also indicate the value to which the current in the coil has to be limited to prevent saturation of the iron or the cores. The Finally procedures for design of LDM are discussed.

• 전기학회논문지
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• 제56권8호
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• pp.1471-1475
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• 2007

In this paper, a novel embedded ultra wideband (UWB) band-pass filter is presented on a FR-4 package substrate including high Dk resin coated copper (${\varepsilon}_r=30$) film. The proposed UWB filter is comprised of a parallel resonator with meander-type uniform impedance resonator (UIR) and two series resonators with high Q circular stacked spiral inductor and metal-insulator-metal (MIM) capacitor. In order to obtain excellent attenuation characteristics by generating attenuation poles in lower and upper stop bands, a single MIM capacitor is added to each resonator. The fabricated FR-4 embedded UWB filter has insertion loss of -1.0dB and return loss of -11dB, respectively. It has also extremely wide bandwidth (over 50%) and small size ($3.7{\times}4{\times}0.77\;mm^3$) which is compatible with LTCC devices.

• 한국포장학회지
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• 제4권1호
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• pp.33-40
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• 1997

The microbial growth of fresh, vacuum packaged, cook-in-bag uncured beef patties was determined in two film structures, a commercial (PE/EVOH), and super barrier ($SiO_2$ coated polyester) material. Packaged samples were cooked to internal temperature of 71 and $82^{\circ}C$ for 30 minutes, and stored in temperature abused ($23{\pm}2^{\circ}C$) and refrigerated storage ($4-6^{\circ}C$). Barrier properties had a significant effect (p<0.001) on aerobic and mesophilic growth in the abused condition. Cooking temperatures had a statistically significant effect (p<0.05) on aerobic growth in the refrigerated condition. The growth of anaerobes and psychrophiles were not significantly effected by either variables. Storage times had the most significant effect (p<0.001) for all groups of microorganisms. The physical properties of the commercial film (strength, thickness, and shrinkage) were changed after exposure to thermal treatment, while the super barrier package had actually no change.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.456-463
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• 1997

Atrium buildings are commonly found in Hong Kong since 1980. Those spaces are usually crowded with people and so fire protection systems have to be installed for providing a safe environment. Smoke control system was identified to be important but no clear design guidelines are available because the smoke filling process was not well-understood. In this paper., Computational Fluid Dynamics(CFD) or fire field model is applied to study the smoke filling pattern in atrium. Two common cases on smoke spreading out from a shop adjacent to the atrium; and with a fire located at the atrium floor itself were considered. Simulations with a modified form of the CFD package TEAM were performed. Application of the predicted results Is illustrated.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.446-450
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• 2008

Urban transits of metropolises have been used by many citizens due to the merits of environment friendly traffic, mass transportation, safety and scheduled operation. It is very important to keep safety for the increased passengers. When the accidents as like fire occur, rapid evacuation from fire site is one of the most effective methods to decrease casualties. Furthermore, overseas buyers sometimes request the verification results of the passenger evacuation from rolling stock. In this study, algorithm for passenger flow analysis based on DEM(Discrete Element Method) is newly developed and made simulation program package. And, we applied it to the evacuation problem for urban transits. By using the developed program, we compared the simulation results of the effects of the location and size of door and elapsed time qualitatively and quantitatively.

• 한국정보시스템학회지:정보시스템연구
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• 제28권1호
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• pp.1-16
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• 2019

Purpose The purpose of this study is to analyze causal relationship between quantity and quality for deriving ranking model of Online reviews. Thus, we propose implications for deriving the ranking model for retrieving Online reviews more effectively. Design/methodology/approach We collected Online review from Tripadvisor web sites which might be a kind of world-famous tourism web sites. We transformed the natural text reviews to quantified data which consists of quantified positive opinions, quantified negative opinions, quantified modification opinions, reviews lengths and grade scores by using opinion mining technologies in R package. We executed corelation and regression analysis about the data. Findings According to the empirical analysis result, this study confirmed that the review length influenced positive opinion, negative opinion and modification opinion. We also confirmed that negative opinion and modification opinion influenced the grade score.

• Communications for Statistical Applications and Methods
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• 제26권2호
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• pp.163-173
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• 2019

Simon's two-stage designs are frequently used in phase II single-arm trials for efficacy studies. A concern of safety studies is too many patients who experience an adverse event. We show that Simon's two-stage designs for efficacy studies can be similarly used to design a two-stage safety study by modifying some of the design parameters. Given the type I and II error rates and the proportion of adverse events experienced in the first stage cohort, we prescribe a procedure whether to terminate the trial or proceed with a stage 2 trial by recruiting additional patients. We study the relationship between a two-stage design with a safety endpoint and an efficacy endpoint as well as use simulation studies to ascertain their properties. We provide a real-life application and a free R package gen2stage to facilitate direct use of two-stage designs in a safety study.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.325-326
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• 2019

본 논문은 텍스트 마이닝 기법으로 명사의 빈도수를 조사하여 워드클라우드를 나타내는 기존의 방법을 개선하여 지능적 워드클라우드를 구현하는 방법을 제안한다. 텍스트 마이닝 시에 명사 단어를 추출하는 사전에 누락된 신조어 등의 단어를 효과적으로 추가하고, 동사 등 다른 품사위주의 워드클라우드를 시각적으로 보여주는 방법을 제안한다. 실험에서 기존 명사의 빈도수 추출에는 KoNLP 패키지를 사용하였고, 지원되지 않는 신조어 80개를 추가하였고 빈도수를 수동으로 조사하여 추가하였다.

• Communications for Statistical Applications and Methods
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• 제28권5호
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• pp.537-551
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• 2021

We conducted a study on a regression spline estimator with a few pre-specified auxiliary variables. For the implementation of the proposed estimators, we adapted a coordinate descent algorithm. This was implemented by considering a structure of the sum of the residuals squared objective function determined by the B-spline and the auxiliary coefficients. We also considered an efficient stepwise knot selection algorithm based on the Bayesian information criterion. This was to adaptively select smoothly functioning estimator data. Numerical studies using both simulated and real data sets were conducted to illustrate the proposed method's performance. An R software package psav is available.

• 무역학회지
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• 제44권6호
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• pp.169-185
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• 2019

The purpose of this study is to analyze the structural relationships of perceived value, price sensitivity, and satisfaction between brand image and purchase intention of consumers who have experience of overseas direct purchase. This study collected questionnaires used to analyze these structural relationships. Using the R's plspm package, we analyzed the PLS (partial least squares) structural equation model. In order to examine the relationship between perceived value and price sensitivity, the research model was modified and analyzed. As a result, not only the adoption of the research hypothesis, but also the goodness of fit was higher than before the research model modifying, and the relationship between perceived value and price sensitivity was further verified. The modified research model has higher academic value, so it is necessary to select it as the final proposal model.