T-바 급전스롯트 안테나 파라미터의 특성에 관한 연구

박한규,김경태,양혁재 연세대학교 산업기술연구소 1980 논문집 Vol.12 No.2

T- 바 給電스롯트 안테나의 입력임피던스와 안테나의 기하학적 구조를 變化함으로써 帶域幅을 최적화 하는 파라미터를 고찰하기 위하여 X-Band에서 가변되는 공진기내에 T-바를 揷入한 T-바를 給電스롯트 안테나를 製作하였다. T-바 給電 스롯트 안테나는 높은 효율과 廣帶域 特性을 갖고 있다. 따라서, 여기서는 廣帶域 特性을 갖도록 하기 위한 설계과정에서 중요한 파라미터를 보여주고자 한다. 중요한 파라미터는 1)급전 점에서 캐비티단락면까지 거리 2)급전 점에서 개구면까지 거리 3)프르브의 길이, 스터브의 직경 4)바의 직경임을 실험적으로 확인했다. This paper describes the design of the T-bar fed slot antenna in the X-band frequency ranges. The T-bar fed slot antenna is designed by inserting a T-bar in a variable rectangular cavity, and the parameter for the optimum bandwidth is observed by varying the input impedance and geometry of a T-bar fed slot antenna. The T-bar fed slot antenna has the characteristics of high efficiency and broad bandwidth. This paper also shows the important parameters to have broad bandwidth characteristics in the design procedure. It is verified experimentally that the important design parameters are 1) the distance from the feed point to the shorted end of cavity, 2) the distance from the feedpoint to the aperture, 3)the length of the crossbar probe and the diameter of the stub, 4) the diameter of the crossbar.

Advanced Treatment of Food Waste Leachate Using the Aeration Reactor with High Efficiency Pure Oxygen

Sang-Houck Lee,Jae-Chun Ko 한국도시환경학회 2010 한국도시환경학회지 Vol.10 No.2

버블시트를 활용한 한중매스콘크리트의 현장적용 및 경제성 분석

경영혁(Kyoung, Young-Houck),한민철(Han, Min-Cheol) 대한건축학회 2020 대한건축학회논문집 Vol.36 No.7

The aim of the research is to verify the efficiency of the double-layered bubble sheets method by evaluating the basic properties and temperature history, and analyzing the economics through the field application under the conditions of mass concrete construction during cold weather. In the case of the fresh concrete, all tested properties of slump, air content, and chloride content were satisfied the target values. Furthermore, the compressive strength at 28 days achieved designed compressive strength. From the temperature history of the mass concrete constructed during cold weather, gradual increase of the temperature up to 50.3℃ was observed about 60 hours after the placing. At this time, the top-surface temperature was 32.6℃ which was 17.7℃ difference to the core part and it could restrain the cracking due to the heat of hydration with 0.85 of thermal crack index. It can be analyzed that the combined effect of decreasing the maximum temperature of the concrete at core part by controlling the mix design to decrease the heat of hydration, and further reducing the temperature difference between top and core parts of the mass concrete by keeping the surface temperature by insulating cure using bubble sheets was successful. The measured values of average curing temperature at all measuring points were confirmed higher than 10℃. Additionally, since all measuring points were calculated 66°DD of maturity, 5 MPa of minimum compressive strength of preventing early-age frozen damage was secured. In aspect of economics, comparing with currently used heat-curing method, the suggested double-layered bubble sheet method showed cost reducing effect in all parts of materials, labor, and other costs. Furthermore, the cost could be reduced more as the number of re-using was increased, so it could reduce 85 % of cost to the currently used heat-curing method.

대중음악 흥행결정요인이 국내대중음악 흥행성과에 미치는 영향 : 기획사와 유통사의 조절효과를 중심으로

김양석,이상혁,Kim, Yang Sug,Lee, Sang Houck 한국벤처창업학회 2015 벤처창업연구 Vol.10 No.1

K-Pop이 사회, 문화 그리고 경제적인 분야에서 긍정적인 요소로 작용하고 있음에도 불구하고, 국내에서는 관련 연구가 아직 활발히 진행되고 있지 않다. 이에 본 연구에서는 대중음악의 흥행결정요인들이 국내대중음악의 흥행성과에 미치는 영향을 규명하고자 하였다. 기존의 선행연구를 바탕으로 대중음악 흥행결정요인을 파악한 후 가수의 역량, 미디어 영향, OST 영향, SNS 영향 그리고 발매 첫 주 순위를 독립변수로 정하였다. 더불어 2013년 7월 둘째 주부터 2014년 7월 첫째 주까지 가온차트 내 디지털차트 순위에 진입한 국내대중음악을 선별하여 100위 순위 내 유지한 기간을 곡 별로 조사한 후 이를 주 단위로 측정하고 흥행성과인 종속변수로 정하였다. 기획사와 유통사의 역량울 조절변수로 설정한 후 국내대중음악의 흥행결정요인과 흥행성과와의 영향관계에 있어서 조절작용을 하는가를 연구가설로 설정하였다. 연구 결과, 가수의 역량, 미디어의 영향과 SNS의 영향 그리고 발매 첫 주 순위 등이 국내대중음악의 흥행성과에 정(+)의 영향을 미치는 변수로 분석되었으나 OST의 영향은 가온차트 내 디지털차트의 순위유지기간에 유의미한 영향을 미치지 못하는 것으로 분석되었다. 기획사의 역량은 자체적으로는 국내대중음악의 흥행성과에 부(-)의 영향을 미치는 것으로 나타났지만, 조절변수로 작용을 할 경우, 대중음악 흥행결정요인과 국내대중음악 흥행성과에 크게 영향을 미치는 것으로 나타났다. 유통사의 역량은 조절변수로 작용을 할 경우, 대중음악 흥행 결정요인과 국내대중음악 흥행성과에 정(+) 영향을 미치는 것으로 나타났다. The purpose of this study is to find the factors of the box office record in Korean popular music. For this purpose, 1.239 musics were selected in the Gaon digital weekly album chart from second week July 2013 to first week July 2014. The result can be summarized as follows: First, entertainment of music company, distribution of music company, singer, OST(Original Sound Track), television show, SNS and high ranking in the first week of its release are the factors of the box office record in Korean popular music. Second, entertainment of a large number of music production company is more effective than the others, but there is no difference in the case of distribution music company. Third, musics of singers who have large number of music ranked Gaon digital chart and appearance of television show program are effective in the box office record in Korean popular music. Fourth, SNS are great factors to promote Korean popular music. Fifth, it is important to rank high position in the first week of its release.

생태계보전협력금 제도 활성화를 위한 부과금 개선 방안 연구

김경호 ( Gyung Ho Kim ),이상혁 ( Sang Houck Lee ) 한국환경복원기술학회(구 한국환경복원녹화기술학회) 2011 한국환경복원기술학회지 Vol.14 No.6

Korea introduced the cooperation charge on conservation of ecosystem for minimizing damage of ecosystem due to development projects and their effects and for preparing resources for natural environment conservation projects. Advanced countries have made efforts by expanding investment in natural environment conservation and restoring projects to promote prevention of global warming and improvement of biological diversity, are establishing nationwide strategies and plans. To examine the reality of projects by returns of the cooperation charge on conservation of ecosystem, microsite projects in schools and public facilities take the largest share while their project budgets are only about 100~300 KRW, relatively small, which might be attributable to budget restrictions in accordance with the calculating method of levying cooperation charge on conservation of ecosystem and problems of project proceeding in the system of returning fund for projects in general. The conclusion which this study suggests on invigoration of cooperation charge on conservation of ecosystem and its operation are as followings. First, although the cooperation charge on conservation of ecosystem has been introduced in 2001, the amount of imposition per unit area remains unchanged. It is desirable to increase the amount into 1,400 KRW/㎡ as of August, 2011 as the price index has been continuously rising for the past 10 years and the upward adjustment of imposition per unit area should be notified by the decree of the Ministry of Environment every January. Second, the ceiling amount of the cooperation charge on conservation of ecosystem should be abolished. Now the ceiling amount is defined as 1 billion KRW but it was found that there was not any ceiling amount specified according to the comparative analysis of similar systems with the Korean environmental improvement fund. The ceiling should be abolished so that medium level businesses are carried out and ecosystem recovering projects in the true sense of the word can be made smoothly. Third, weight should be introduced in calculating amounts in accordance with ecologic and economic values. Harmony between development and environment can be achieved by applying differentiated weights of constant regional coefficient by use zone and ecologic and economic values. Continuous efforts of improving cooperation charge on conservation of ecosystem should be made more than anything else so that projects by returns of cooperation charge on conservation of ecosystem get effectiveness.

硏究論文 : 영산강,섬진강 수계 수변구역 매수토지의 관리 현황 및 개선 방안- 순천시 지역을 중심으로-

변성수 ( Seong Soo Byon ),이상혁 ( Sang Houck Lee ) 한국환경복원기술학회(구 한국환경복원녹화기술학회) 2012 한국환경복원기술학회지 Vol.15 No.6

This study observes the purchased lands in riparian areas of Suncheon City region and proposes a reasonable management method. For the study, the site surveying and analysis on the neglected purchased lands is executed, then, based on the site analysis result, the appropriate management method for each neglected purchased land is established. Each management method is approached from the ecological restoration perspective. According to site surveying and analysis of the neglected purchased lands, most of the sites were bare and agricultural lands. The reason for this is thought to be as when purchasing a land, the areas with higher nonpoint source pollution are bought preferentially. As for the dominant species coverage, 26% (364,000m2) of the total neglected purchased land area in Sucheon City was covered with the dominated species, and for the exotic species coverage, 17% (232,000m2) of the total neglected purchased land area in Sucheon City was covered with the exotic species. The survey site constituted of five different invasive species such as Japanese Hop (Humulus japonicus), Daisy Fleabane (Erigeron annuus), and Evening Primrose (Oenothera odorata). As for the natural succession on site, about 47% of the area showed poor natural succession process. The reason for this outcome is understood as having a lack of appropriate management for purchased lands. Based on the site surveying and analysis, especially the current management state of the and its location, the research site was categorized into preservation, restoration, and improvement sites. During the establishment of the ecological riparian belt, the comprehensive management for preservation, restoration, and improvement of the purchased lands should be executed.

Biosorption of Chromium (VI) from Electroplating Wastewater using Pine Cone Powder

Chun-Ji Jin,Jiang-Li Shen,Sang-Houck Lee,Bo Xiao,Ping Yang 한국도시환경학회 2010 한국도시환경학회지 Vol.10 No.2

라돈 저감제를 이용한 건축자재의 라돈 방출 저감 연구

박경북,이상혁,Park, Kyung-Buk,Lee, Sang-Houck 한국환경보건학회 2014 한국환경보건학회지 Vol.40 No.6

Objectives: A radon emission reducing agent was prepared using charcoal and zeolite, and the amount was measured after coating construction materials with the agent. The availability of the radon emission reducing agent was evaluated. Methods: Construction materials (red brick, cement brick, and gypsum board) coated with reducing agent were placed in a chamber to measure radon emissions. The construction materials were coated one through three times. The spread volume for brick and gypsum board was 50 mL and 75 mL per application, respectively. The amount of radon emitted was measured by RAD-7 after 48 hours. Results: The reduction ratio increased with the number of coatings, and the reduction ratios for red brick, cement brick, and gypsum board were 63.3, 73.6, and 58%, respectively, in the case of three coatings of RA-1. The reduction ratios for red brick, cement brick, and gypsum board were 42.8, 58.1, and 26.2%, respectively in the case of three coatings with RA-2. RA-1 was slightly better than RA-2 in radon emission reduction. Conclusions: Radon emissions from construction materials decreased according to the concentration of reducing agent coating, and it was more effective than existing methods.

고농도 질산성 질소를 함유한 산세폐수의 생물학적 처리에 관한 연구

박상진 ( Sang Jin Park ),이상혁 ( Sang Houck Lee ) 한국물환경학회 2015 한국물환경학회지 Vol.31 No.3

The purpose of this study is the efficient biological treatment of highly concentrated nitrate nitrogen by calcium ion control present within the pickling wastewater. In laboratory scale’s experiments research was performed using a sequencing batch reactor and the evaluation of denitrification reaction in accordance with the injection condition of calcium ions, the surface properties of microorganisms, and the evaluation of sludge precipitability were performed. Results of the study showed that the denitrification reaction was delayed when injecting more than 600 mg/L of the calcium ion within the denitrification process. In addition, we observed the absorption form of calcium ions absorbed on the surface of microorganisms following an increase in the calcium ion dose. It was found that as the calcium ion dose increased the sludge precipitability also increased continuously and it is judged that a smooth denitrification induction is possible when treating the nitrate nitrogen by the calcium ion control of pickling waste water and the shortening of precipitation time enables a liquid operation to increase the reaction time.

State of the Art of Biodegradable Nanofluids Application in Machining Processes

Vitor Baldin,Leonardo Rosa Ribeiro da Silva,Alisson Rocha Machado,Celso Ferraz Houck 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.5

For ecological and health issues of those involved in the manufacturing, usage, handling, and disposal of cutting fluids, research has been developed for scientific and technological advances in biodegradable cutting fluids, application methods, and solid nanolubricants. Using a minimum quantity of lubricant (MQL) in machining processes proved to be a viable alternative to replacing low-pressure jet machining. Nanoparticles from 5 to 100 nm in size are usually dispersed in vegetable-based cutting fluid; this combination improves the tribological properties of the nanofluid and the machinability of metal alloys like steel, titanium, nickel, and aluminum alloys, with reduced cutting forces, cutting temperature, tool wear and workpiece surface roughness. This work aims to present an updated summary of the lubrication and cooling action provided by using the MQL technique, biodegradable cutting fluids applied by MQL, the use of nanoparticles added to the cutting fluids, and the physical properties of nanoparticles, tribological characteristics, and the behavior of the nanofluids. The changes in machining force, cutting temperature, surface integrity, and wear of cutting tools with biodegradable nano-cutting fluids are also focused on. The use of nanoparticles in cutting fluids associated with MQL application has shown an increase in the lubricating and coolant properties of cutting fluids, which contribute to the reduction of machining force, cutting temperature, workpiece surface roughness, coefficient of friction, and wear of cutting tools. Thus, the results of this summary can provide theoretical support and experimental guidance for exploring the lubricating and cooling properties and the mechanism present in film formation with nanofluids at the chip-too-workpiece interfaces. Knowledge of such phenomena helps to popularize an eco-friendly practice in metal-mechanic industries.