• 한국통신학회논문지
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• 제39B권10호
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• pp.700-707
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• 2014

본 논문에서는 순환적 전치 부호를 가지는 시스템에서 수신기에 나타나는 잡음신호를 제거하는 기법에 대해 다룬다. 수신된 블록의 SNR을 추정하여 잡음신호가 작을 때 수신된 블록으로부터 자기상관행렬을 구하고, 신호 부분공간(signal subspace)에 속하는 고유벡터를 자기상관행렬의 고유치 분해를 통해 얻는다. 신호 고유벡터를 위한 자기상관행렬은 수신된 블록의 순환적 특성을 사용하여 얻는다. 일반적인 OFDM 시스템에서는 순환적 전치 부호를 가지는 심볼을 전송하기 때문에 본 논문에서 제안한 방법은 송 수신기의 구조를 변경하지 않는 장점을 가진다. 고유필터를 위해 얻어진 신호 고유벡터를 사용하여 수신된 블록을 필터링함으로써 잡음신호를 제거한다. 제안된 방법의 타당성 검증을 위해 송신 신호에 대한 영구 여기(persistency of excitation) 조건을 확인하고 시뮬레이션을 통해 검증한다.

• 태양에너지
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• 제18권3호
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• pp.41-50
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• 1998

일반적으로 최종적인 건물 설계에 의한 건물의 에너지 성능은 거주후평가(POE)에 의해 이루어지게 되며, 축적된 평가 결과는 설계에 의한 시행착오를 예측하기 위한 새로운 설계의 Feedback 자료로 이용되어져야 한다. 그러나 이러한 기존 건물의 에너지 평가자료가 구체적으로 편집되어 제시되어 있지 못한 현 실정에서 본 조사는 설계시에 에너지 성능을 비교할 수 있는 척도를 제공해 줄 수 있을 것이며, 추후 건물 에너지 성능규제를 위한 기초 자료가 될 수 있을 것이다. 이에 대전 및 인근지역 35개 공공건물의 건물에너지소비의 패턴이 조사되었으며, 우선 전화국, 백화점, 병원, 연구소, 스포츠센터 수영장, 전시관, 대학교, 호텔의 8개 건물로 분류하였다. 그러나 많은 수의 공공건물은 여러 가지 복합적인 기능을 갖추고 있고 따라서, 건물의 이름만으로 건물의 에너지소비패턴을 분석하기 위하여 (1) 준공연도, (2) 층수, (3) 단열정도, (4) 주연료, (5) 난방면적, (6) 연간난방일수, (7) 평균난방실내온도, (8) 냉방면적, (9) 평균냉방실내온도, (10) 보일러형식, (11) 보일러대수, (12) 보일러용량, (13) 보일러연료사용량, (14) 전기사용량, (15) 최대부하등이 조사되었다.

• 설비공학논문집
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• 제16권2호
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• pp.150-157
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• 2004

Carbon dioxide ($CO_2$, R-744) has become a very popular issue in application to refrigeration and air conditioning systems as a natural refrigerant. An experimental study has been carried out to investigate miscibility and the vapor pressure of refrigerant R-744 in the presence of lubricant oil. This is of particular interest in the selection of the lubricant oil for the compressor of a refrigeration system or an air conditioning system using the refrigerant R-744. The experimental set-up consists of the equilibrium cell, measuring devices, the vacuum pump, the constant temperature bath and relevant connecting pipes made of stainless steel. Five lubricant oils, such as mineral oil (Naphthenic), AB (Alkyl Benzene) oil, PAO (Poly Alpha Olefin) oil, PAG (Poly Alkylene Glycol) oil and POE (Polyol Ester) oil are considered in the present study. Test runs were conducted with the oil concentration range from 5 to 50 wt％, and the temperature range from -10 to 1$0^{\circ}C$ with 2$^{\circ}C$ intervals. The miscibility results are visualized and correlated with the vapor pressure for the individual test components.

• 설비공학논문집
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• 제11권1호
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• pp.31-37
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• 1999

In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method to measure the oil concentration is to extract the working mixture and then to measure the oil weight. However, it is Quite necessary to estimate oil concentration without any extraction of the working fluid. In this study a new method and working equation is presented as follows. It is based on the measurement of spedific gravity and temperature : $$C=a+b{\times}t+c{\times}t^2+(d+e{\times}t+f{\times}t^2){\times}SG$$ C is oil concentration, t is temperature($^{\circ}C$), SG is specific gravity of mixture and a~f is coefficients. The oil concentration ranges over 0~12 wt% and the temperature ranges over $20{\sim}50^{\circ}C$. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/POE oil oiquid mixtures.

• 한국응용과학기술학회지
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• 제10권2호
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• pp.35-40
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• 1993

Alkaline cleaning agent(ACA) was prepared by blending of POE(4)octadecylmine(S-204), $Na_2CO_3$, sodium orthosilicate(Na-OSi). Tetronix T-701(T-701), and MJU-100A. The physical properties of ACA tested with steel specimen showed the following results. The cleaning powers of ACA-6(S-204 80g/$Na_2CO_3$, 160g/Na-OSi, 80g/T-701, 60g/MJU-100A, 20g mixture) for press-rust preventing oil was 98% and 99% degreasing at 2wt%, $70^{\circ}C$ and $90^{\circ}C$, respectively : for quenching oil, the cleaning power of ACA-6 was 95% degreasing at 2wt% and $70^{\circ}C$. From these results, it was ascertained that ACA-6 exhibited a good cleaning power. Foam heights measured immediately after foaming by Ross & Miles method and Ross & Clark method at 3wt%. $60^{\circ}C$ were 17mm and 40mm, respectively. As the result, ACA-6 was proved a good low foaming cleaning agent.

• 대한한방내과학회지
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• 제12권1호
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• pp.166-182
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• 1991

This study has been carried out to investigate the cause and symptom of Hae su (咳嗽) cause by a cold referring to 25 literature. 1. Cause : wind (風), cold (寒), heat (署), moisture (濕), dryness (燥), fire (火). It appears to cause double and above. 2. Symptoms : PunghanHaeSu (風寒咳嗽) ; HaeSu (咳嗽), Balyul (發熱), DamHueSaegBaeg (痰稀色白), Hu Yang Sung Tag (喉痒聲濁), BiSaegYuChe (鼻塞流涕), OhPungHan (要風寒), DooShinTong (頭身痛), TaeBaqBaeg (笞薄白), Maeg Bu Gin (脈浮緊). PungYeulHaeSu (風熱咳嗽) ; HaeSu (咳嗽), DamJo (痰稠), SaegHwang (色黃), KaegChulBulSang (喀出不痰), KuKallnTong (口瀉咽痛), BalYeul (發熱), OhPungYuHan (要風有肝), HogYuDuTong (或有頭痛), TaeBagHwang (笞薄黃), Maegbusag (脈浮數). JoYeulHaeSu (燥熱咳嗽) ; KunHaeMuDarn (乾咳無痰), HogDamJungDaeHyulSa (或痰中帶血絲), HaelnHungTong (咳引胸痛), BiJolnKun (鼻燥咽乾), pliogyuOhPungBalYeul (或要風發熱), TaeBagHqangIKun (笞薄黃而乾), MaegSeSag (脈細數). 3. Treatment ; PungHanHaeSu ; SoPungSanHan (疏風散寒), Sun PaeJiHae (宣肺止咳), PungYeulHaeSu ; SoPungchungYeul (疏風淸熱), SunPaeJiHae (宣肺止咳), JoYeulHaeSu; CheongPoeYunJo (淸肺潤燥), SaengJinJiHae (生津止咳). Basing on the literature research, I found that Hae Su (咳嗽) caused by a cold belong to category of YugEum(六淫).

• 한국전기전자재료학회논문지
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• 제32권4호
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• pp.307-312
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• 2019

Transient earth voltage (TEV) signals propagate on metal surfaces when partial discharge (PD) occurs due to the deterioration of insulation performance in the operation of gas-insulated switchgears (GIS). A TEV sensor has advantages of high sensitivity and convenient installation for detecting PD defects. However, the TEV sensor depends on imports in domestic and detailed studies have not been conducted. In this study, a sensor was designed and fabricated by the TEV principle and its response characteristics were evaluated for detecting PD defects, which were simulated as protrusion on conductor (POC), protrusion on enclosure (POE), and free moving particle (FMP) defects. Finally, the PD-induced TEV signals were measured and phase-resolved partial discharge (PRPD) patterns were analyzed to identify the type of defect.

• 한국식생활문화학회지
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• 제36권1호
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• pp.28-39
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• 2021

This study considered the rite of passage ceremonial food in the Mid-Choseon Period through the rite of passage ceremonies, food, and ingredients recorded in the Seoul Noble Ohhweemun Family Diary Shaemirok. The research used a contents analysis method through case studies. The noble families in the Mid-Choseon Period deemed the Jerye to be the most significant out of the traditional ceremonies. The nobles practiced the Sadehbongsah and the Yoonhweebongsah ceremonies for their ancestors. The Rite of passage ceremony required fruit. Of fish and birds, pheasants were used frequently during the ceremonies. Noble families, specifically the richer families, could sustainably normalize the rite of passage ceremonies against the elements. Seasonal ingredients were generally harvested even during spring and winter in large amounts. One of the last rites of passage food by Garye displayed diverse ingredients, such as Bangaeng, Myun, Tang, Uhyookjuk, Poe, Chae, Hae, and Silgwa. Such ingredients prove that the normalization of rite of passage ceremony food was well established and practiced. On the other hand, the birthday rite of passage food did not conform to a specific rite of passage normalcy or preparation. Instead, the birthday food showed a flexible menu of seasonal delicacies that were not confined to a particular traditional formula.

• 한국정보시스템학회지:정보시스템연구
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• 제31권3호
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• pp.109-129
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• 2022

Purpose The purpose of this study is to examine whether customers' shadow work and risk perception have an impact on revisit intention to the fast-food restaurant, with mediating role of different types of attribution tendencies. We also added perceived unfairness in the research model, in order to verify its mediating effect on the relationship between attribution tendencies and revisit intention. Design/methodology/approach Applying the shadow work perspective and attribution theory, we designed a research model to confirm the hypotheses. After collecting the data from 331 customers who have used self-service technology in a fast-food restaurant, we conducted an analysis of measurement model and structural model by using Smart-PLS 3.0. Findings This study confirmed that Forced Use of self-service technology can enhance the tendency of dispositional attribution which would negatively affect perceived unfairness and revisit intention. On the other hand, affective risk perception was proven to affect situational attribution, which positively affects revisit intention.

• 한국건설관리학회논문집
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• 제24권5호
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• pp.83-94
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• 2023

In order to devise a rebar usage optimization algorithm, it is necessary to calculate the exact rebar length and revise the arrangement of rebars into special lengths. However, the process of rearranging numerous rebars and manually calculating their quantities is time-consuming and requires significant human resources. To address this challenge, it is necessary to develop an algorithm that can automatically estimate the length of rebars and calculate their quantities. This study aims to create an automatic estimation algorithm that improves work efficiency while ensuring accurate and reliable calculations of rebar quantities. The algorithm considers various factors such as concrete cover, hook length, development length, and lapping length, mandated by the building codes, to calculate the quantity of rebars for wall structures. The effectiveness of the proposed method is validated by comparing the rebar quantities generated by the algorithm with manually calculated quantities, resulting in a difference rate of 1.14% for the hook case and 1.37% for the U-bar case. The implementation of this method enables fast and precise estimation of rebar quantities, adhering to relevant regulatory codes.