• Journal of Communications and Networks
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• 제17권6호
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• pp.656-664
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• 2015

This study analyzes the performance of power-line communications for sending open automated demand response (OpenADR) signals. In particular, we study main channel disturbances that can affect end-to-end communications and which have not been previously studied in detail. Our analysis takes into account physical phenomena, such as background and impulsive noise sources, channel attenuation, and multipath effects, and considers the physical, network, and applications layers of the communications structure. The performance of the physical layer is the basis for computing the packet error rate. In analyzing application performance, we focus specifically on the latency in several communication environments. If a channel is impaired only by background noise, latencies are less than 40 seconds. With the addition of impulsive noise in the channel, this value increases as long as 68 seconds. Using these figures, we find that power-line technology is more suitable for "slow" demand programs, such as day-ahead or day-of curtailments, rather than ancillary services markets, which require near-real-time communication.

• 한국광학회지
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• 제32권6호
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• pp.276-285
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• 2021

본 논문은 디스플레이용 OLED의 제작 공정에 사용하는 레이저 박리(laser lift-off, LLO) 장비의 선형빔 광학계에 대한 연구로서, M²가 큰 레이저를 사용하는 경우, 단축의 선폭을 작게 만들면서 공정심도를 깊게 유지하기 위한 빔 변환 모듈(beam transformation unit, BTU)을 포함한 광학계에 대한 연구를 진행하였고, 단축 형상을 슈퍼 가우시안으로 만들 수 있는 방법과 flat-top 분포로 만들 수 있는 광섬유를 사용하는 빔 변환 방식에 대하여 제시하였다.

• 천문학회지
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• 제56권1호
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• pp.23-33
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• 2023

We investigate the diffusion process of Thomson-scattered line photons in both real space and frequency space through a Monte Carlo approach. The emission source is assumed to be monochromatic and point-like embedded at the center of a free electron region in the form of a sphere and a slab. In the case of a spherical region, the line profiles emergent at a location of Thomson optical depth τ_Th from the source exhibit the full width of the half maximum σ_λ ≃ τ^1.5_Th. In the slab case, we focus on the polarization behavior where the polarization direction flips from the normal direction of the slab to the parallel as the slab optical depth τ_Th increases from τ_Th ≪ 1 to τ_Th ≫ 1. We propose that the polarization flip to the parallel direction to the slab surface in optically thick slabs is attributed to the robustness of the Stokes parameter Q along the vertical axis with respect to the observer's line of sight whereas randomization dominates the remaining region as τ_Th increases. A brief discussion on the importance of our study is presented.

• 말소리와 음성과학
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• 제6권4호
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• pp.3-15
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• 2014

An articulatory study (using an Electromagnetic Articulography, EMA) was conducted to explore effects of prosodic boundary strength (Intonational Phrase/IP versus Word/Wd), and focus (Focused/accented, Neutral, Unfocused/unaccented) on the kinematic realization of /m/ in the coda (${\ldots}$am#i${\ldots}$) and the onset (${\ldots}$a#mi${\ldots}$) conditions in Korean. (Here # refers to a prosodic boundary such as an IP or a Wd boundary). Several important points have emerged. First, the boundary effect on /m/s was most robustly observed in the temporal dimension in both the coda (IP-final) and the onset (IP-initial) conditions, generally in line with cross-linguistically observable boundary-related lengthening patterns. Crucially, however, in contrast with boundary-related slowing-down effects that have been observed in English, both the IP-final and IP-initial temporal expansions of Korean /m/s were not accompanied by an articulatory slowing down. They were, if anything, associated with a faster movement in the lip opening (release) phase (into the vowel). This suggests that the mechanisms underlying boundary-related temporal expansions may differ between languages. Second, observed boundary-induced strengthening effects (both spatial and temporal expansions, especially on the IP-initial /m/s) were remarkably similar to prominence (focus)-induced strengthening effects, which is again counter to phrase-initial strengthening patterns observed in English in which boundary effects are dissociated from prominent effects. This suggests that initial syllables in Korean may be a common focus for both boundary and prominence marking. These results, taken together, imply that the boundary-induced strengthening in Korean is different in nature from that in English, each being modulated by the individual language's prosodic system. Third, the coda and the onset /m/s were found to be produced in a subtly but significantly different way even in a Wd boundary condition, a potentially neutralizing (resyllabification) context. This suggests that although the coda may be phonologically 'resyllabified' into the following syllable in a phrase-medial position, its underlying syllable affiliation is kinematically distinguished from the onset.

• Nutrition Research and Practice
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• 제2권4호
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• pp.259-268
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• 2008

Children's food behaviors have been expressed in a various ways because of recent changes in their family environment. Thus, this study was performed to investigate in-depth qualitative research on the mother's perception on children's food behaviors by focused group interview. This study was designed in four steps of planning, collection of participants, process, and analysis. Participants for the focus group interview were recruited and sampled from households with elementary school students in the Seoul and Gyeonggido areas. Groups were divided by total income and education expense levels. 1) High income household: It is better to improve currently existing web sites for nutrition education. 2) Mid income household: Easy, practical, and inexpensive off-line cooking class/nutrition education classes for mothers are needed. Nutrition programs for children should be developed through mass media and be promoted in the broadcasting circle. 3) Low income household: Motivation is required for mothers' educatior and the serious nutritional problems of children should be informed through mass media and home correspondence from school. And interesting educational materials should be developed for children to read whenever they want.

• 한국과 국제사회
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• 제2권2호
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• pp.131-156
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• 2018

이 논문은 북아프리카의 '아랍 Maghreb 연합'(AMU) 지역조직의 체제형태가 정체성에 어떻게 영향을 미치는가에 초점을 맞추어 지역주의와 지역조직에 접근하고 재고하기 위한 시도이다. 이 논문의 초점은 지역주의를 연구하는 비전통적인 방법으로서 국내 정치의 중요성에 대해 다룰 것이다. 그리고 지역주의에 대한 많은 연구들과 달리, 이 논문은, 일반적으로 보안이나 경제에 오래된 지역주의 패러다임의 결과로 초점을 맞추는 현실주의자들과 자유주의자들이 강조한 것과는 달리, 이 논문은 지역주의를 이해하기 위한 지침으로 국내 정치를 강조할 것이다.

• 한국레이저가공학회지
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• 제16권3호
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• pp.22-26
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• 2013

Fiber laser welding was performed on SUS Materials metal bellows. The results can be summarized as follows: When we tried to change welding focus location. we get the best welding line when focus location placed 0mm. In product welding, We could make a satisfactory product in constant area by applying optimized conditions and show a table that is able to help producer easily to apply it to manufacturing. In comparison with existing TIG and plasma welding, welded bellows by fiber laser has faster processing speed, smaller thermal effect, very narrow welding area and fine surface.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.585-589
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• 2004

This paper deals with the algorithm development that inspects defects such as Lens Focus, Black Defect, Dim Defect, Color Defect, White Balance, and Line Defect caused by the process of Compact Camera Module (CCM). These days the demand of CCM goes on increasing in various types like PDA, a cellular phone and PC camera every year. However, owing to the defect inspection of CCM by the semiskilled work the average inspection time of CCM takes about 40 to 50 seconds. As time goes by the efficiency takes a sudden turn for the worse because workers must inspect with seeing a monitor directly. In this paper, to solve these problems, we developed the imaging processing algorithm to inspect the defects in captured image of assembled CCM. The performances of the developed inspection system and its algorithm are tested on many samples. Experimental results reveal that the proposed system can focus the lens of CCM within 5s and we can recognize various types of defect of CCM modules with good accuracy and high speed.

• Journal of Information Processing Systems
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• 제17권5호
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• pp.960-971
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• 2021

As the era of the 4th Industrial Revolution enters, the importance of software safety is increasing, but related systematic educational curriculum and trained professional engineers are insufficient. The purpose of this research is to propose the high priority elements for the software safety education program through needs analysis. For this purpose, 74 candidate elements of software safety education program were derived through contents analysis of literature and nominal group technique (NGT) process with five software safety professionals from various industries in South Korea. Targeting potential education participants including industrial workers and students, an on-line survey was conducted to measure the current and required level of each element. Using descriptive statistics, t-test, Borich needs assessment and Locus for focus model, 16 high priority elements were derived for software safety education program. Based on the results, suggestions were made to develop a more effective education program for software safety education.

• 복식
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• 제66권4호
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• pp.146-165
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• 2016

The aim of the study is to propose ways to improve the break line fit of women's tailored collar vests by modifying the patternmaking process. The study explored the fit effects of experimental vests with a focus on 3 different breast sizes, A, B, and C cups. Women in the ages between 20 and 24 in South Korea were targeted. In order to carry out the objective, the study implemented separate girth measurements for the front and the back of the tailored collar vests, and also allocated different dart amounts on the lapel through the break line according to the different breast cup sizes. The study adopted a 5-point rating scale to perform evaluation of the different fit effects caused by the varying dart amounts given on the experimental vests' break lines. This evaluation was carried out by apparel pattern experts. The results derived from the study were as follows: first, the implementation of separate girth measurements provided originality to the study, as the application of different measurements for the waist back length and the neck shoulder point-to-breast point-to-waist line led to the front panels of the experimental vests having varying slack amounts. Second, break line dart was applied in three different amounts, 0.5, 1.0, and 1.5cm respectively according to A, B and C breast sizes, and as the dart amount increased, extra ease on the break lines was reduced. The dart was applied on the edge lines of the lapel and it was applied from a point which was 6cm above the breast point to the end of the princess line for all the breast cup sizes.