CO₂ 압축기의 운전조건과 오일토출의 상관분석에 관한 실험적 연구

이익수,강병하,Lee, Ik-Soo,Kang, Byung-Ha 대한설비공학회 2011 설비공학 논문집 Vol.23 No.1

A portion of oil for lubrication of compressor flows together with refrigerant in the refrigeration system. If the oil discharge from a compressor is increased in the refrigeration system, not only pressure drop is increased in other components, such as evaporator and gas cooler, but also heat transfer coefficient in the heat exchangers is decreased. Oil discharge rate from a compressor may strongly depend on operating conditions of a compressor. In this study, one stage single rotary compressor is employed for measuring oil circulation ratio(OCR). Carbon dioxide and PAG oil are used as refrigerant and lubricant. Using a U-tube densimeter, mixture density is measured. Oil circulation ratio(OCR) can be estimated by measured mixture density. The results obtained indicate that the oil circulation ratio(OCR) is increased as the suction temperature or compressor operating frequency is increased. Oil circulation ratio(OCR) correlation of the compressor is also suggested.

하이퍼카오스 신호발생을 위한 HVPM 모델 및 회로 구현

이익수(Ik-soo Lee),이동록(Dong-rok Lee),여지환(Ji-hwan Ryeu),송규익(Kyu-ik Sohang) 대한전자공학회 2000 대한전자공학회 학술대회 Vol.2000 No.11

동기요인에 따른 스포츠관광지 이미지의 차이분석

이익수(Ik Soo Lee) 한국관광연구학회 2004 관광연구저널 Vol.18 No.1

This study is analysed the Tourist`s behavior in order to identify of attributes factor of sports tourism destination image at the Dae-jeon city. Attributes factor of sports tourism destination image are formed based on the perception of physical attributes of a tourist place and plays an important role in changing primary awareness set into secondary awareness set. Data is corrected form world-cup stadium in the Dae-jeon city. The statistical analysis of the data is conducted using techniques of frequency analysis, factor analysis, t-test, ANOVA, regression analysis. The results of this study analysis is analyzed that attributes factor of sports tourism destination image is very much affected to factor 1 and 5 in the Dae-jeon city.

피드백 마스킹 기법을 사용한 카오스 음성비화통신

이익수(Ik-Soo Lee),여지환(Ji-Hwan Ryeu) 한국지능시스템학회 2002 한국지능시스템학회 학술발표 논문집 Vol.12 No.2

자기피드백 마스킹 기법을 사용한 카오스 음성비화통신

이익수(Ik-Soo Lee),여지환(Ji-Hwan Ryeo) 한국지능시스템학회 2003 한국지능시스템학회논문지 Vol.13 No.6

시방공작물 시공이 저서성 대형무척추동물 군집에 미치는 영향

이익수 ( Ik Soo Lee ),정유경 ( Yi Gyeong Jung ),이헌호 ( Heon Ho Lee ) 한국산림과학회 2012 한국산림과학회지 Vol.101 No.4

This study was conducted to investigate that affect benthic macroinvertebrates for installed erosion control works at a mountain torrential stream. The survey was carried out six times from April 2007 to October 2008 at two points where erosion control works were installed and at a control point in the upstream with no such works. Variations in the community structure and cluster of benthic macroinvertebrates and ecological water quality were analyzed in the survey. From the six times survey the identified benthic macroinvertebrates were 6,922 individuals belonged to 27 species 24 families 13 orders 6 classes and 4 phyla. As the average results of three surveyed sites the dominant species was Gammarus sobaegensis of Amphipoda. The species diversity index (H`) showed the highest as 1.47 at Site 2 of the fourth survey and the lowest as 0.24 at Site 2 of the sixth survey. The evenness Index (EI) showed the highest as 2.794 at Site 1 of the first survey and the lowest as 0.291 at Site 2 of the sixth survey. The ecological score of benthic macroinvertebrate community (ESB) and individual of EPT-group were declined during the survey period. The functional feeding group (FFG) showed the highest SH types during the survey period.

지역상징물과 이미지와의 관계

이익수(Lee ik-soo) 한국콘텐츠학회 2009 한국콘텐츠학회 종합학술대회 논문집 Vol.7 No.1

본 연구는 충청북도 지자체의 상징물과 관광이미지(테마)와의 부합성을 살펴보고 문제점을 도출함으로써, 향후 대책의 기초를 마련하고자 하였다. 연구결과 충청북도내의 각 지자체의 상징물과 관광테마는 일관된 이미지를 홍보하기 어려운 것으로 나타났으며, 이는 관광홍보라는 측면에서 많은 어려움을 야기할 수 있는 요소인 것으로 나타났다. 향후 대책은 첫째, 지역 홍보물과 연계되면서, 관광테마를 수용할 수 있는 연결고리식의 관광 상징물을 제작해야 하며, 둘째, 관광테마와 부합되는 슬로건으로 구성해야 하며, 셋째, 연계성을 가질 수 있는 관광홍보방안을 수립하여 시행해야 한다. The research which sees observed the region symbol and tourism image(theme) of ChungCheongbuk-Do oneself and saw and problem point with the escape box, foundation of hereafter countermeasure under preparing boil. The region symbol and tourism theme of research result ChungCheongbuk-Do undergarment each oneself the image which is consistent public information description below appeared with the difficult thing, this is many being difficult from the side which is sightseeing public information, appeared with the fact that is an element will be able to cause. The hereafter countermeasure first, when becomes the area public information water and connection, from, must produce tourism symbol of the inter linkage will be able to accommodate tourism theme, second, must compose of the slogan which corresponds with tourism theme, three, must enforce establishes tourism information plan which is the possibility of having a connectedness.

비선형 매핑회로를 이용한 HVPM 모델의 구현

이익수(Ik-Soo Lee),여지환(Ji-Hwan Ryeu) 한국지능시스템학회 2001 한국지능시스템학회논문지 Vol.11 No.1

본 논문에서는 복잡한 하이퍼카오스 신호를 발생시키는 HVPM(Hyperchaotic Volume Preserving Maps) 모델의 회로를 제안하고, 보드상에서 구현하고자 한다. 제안한 HVPM 모델은 3차원 이산시간(discrete-time) 연립차분방정식으로 구성되어 있으며, 비선형 사상(maps)과 모듈러(modulus) 함수를 사용하여 랜덤한 카오스 어트랙터(attractor)를 발생시킨다. 이러한 HVPM 모델을 하드웨로 구현하기 위하여 연산 부분은 연산증폭기를 사용하고, 매핑(mapping) 부분은 N형 함수와 비교기를 사용하여 설계한다. 특히, N형의 비선형 함수는 CMOS 전달특성과 선형증폭기의 출력특성을 조합하여 독특하게 구현하였다. 구현한 보드상의 실험에서 카오스 시스템 파라미터 값에 대응하는 가변저항기를 조절하여 비주기적인 하이퍼카오스 신호를 발생시킴을 입증하였다. 또한 출력된 카오스 신호들간의 오실로스코프 사진에서 위상공간(phase space)의 동적응답은 랜덤한 어트랙터를 발생시킴을 확인할 수 있었다. In this paper, we propose a new analog circuit of HVPM(Hyperchaotic Volume Preserving Maps) model for generating the complicated hyperchaotic signals and implement the chaotic signal generation circuit on the board level The proposed chaotic equation, that is, HVPM model which consists of three dimensional discrete-time simultaneous difference equations and shows uniquely random chaotic attractor using nonlinear maps and modulus function. It is designed of a analog circuit to implement the hardware system which is built of math blocks using operational amplifiers and mapping blocks using N-type nonlinear circuits and comparators. Specially, we develop the N-type nonlinear circuit that consists of CMOS and linear amplifier transfer characteristic property. In the hardware experimental results, we demonstrate the generation of nonperiodic chaotic signals with changing the variable resistor corresponding to chaotic system parameters. And, we prove the patterns of random chaotic attractor on oscilloscope traces with the plot of phase spaces.

III분과 : 감수곡선을 이용한 산림소유역 유출특성의 시계열 변화 평가

이익수 ( Ik Soo Lee ),이헌호 ( Heon Ho Le ) 한국임학회 2014 한국산림과학회지 Vol.103 No.3

본 연구는 주지하수 감수곡선을 이용하여 산림소유역의 유출특성을 밝히기 위하여 수행하였다. 2003년부터2011년까지 9년간 관측한 강우-유출량 자료를 이용하여 수문곡선 감수부의 시계열 변화를 분석하였다. 그 결과 산림소유역에서는 직접유출 감수계수가 기저유출의 감수계수 값보다 작았다. 또한 산림소유역에서의 직접유출량은 대유역에 비해 상당히 적은 양을 보였으며, 기저유출량은 차이가 크지 않았다. 시험유역에서 주지하수 감수곡선의 회귀식과 감수계수는 각각 y = 0.7528e-0.022x(R2=0.8938, 범위는 0.3 mm~0.8 mm), K = 0.978로 산출되었다. 주지하수 감수곡선과 연유출량과는 관련성이 큰 것으로 나타났는데, 유출량이 많으면 주지하수 감수곡선의 기울기가 완만해지고,유출량이 줄어들면 감수곡선의 기울기가 급해지는 것으로 나타났다. 또한 해를 거듭할수록 주지하수 감수곡선의 기울기가 완만해지는 경향이 나타나, 점차 기저유출량이 증가하는 것으로 판단하였다. 따라서 시험유역에서는 시간의경과와 함께 산림의 홍수조절기능 및 수원함양기능이 점진적으로 높아지는 것으로 나타났다. Long-term changes in the hydrological characteristics of a small forest watershed were examinedusing a master baseflow recession curve and the measured rainfall-runoff data from the experimental forestwatershed in the measured years 2003-2011. The results of the study showed that the recession coefficient ofdirect runoff was lower than that of baseflow. In small forested watershed, the direct flow was lower than thatof large scale watershed, flow due to its shorter period of occurrence. And baseflow was similar to large scalewatershed’s. A regression equation y = 0.7528e-0.022x(R2=0.8938, range 0.3~0.8 mm) was obtained using themaster baseflow recession curve for the study period and the recession coefficient was calculated as K = 0.978.Changes between master baseflow recession curve and runoff showed great association and relevance such asincreasing runoff was associated with the gentle slope of master baseflow recession curve and decreasing runoffwas associated with the slope of master baseflow recession curve contrary. In the later years of the study period,the slope of the master baseflow recession curve appreciably became more gentle due to increases in baseflow.This suggests that the forested experimental watershed exhibit improved structural functioning of normal floodcontrol and reduced occurrence of water shortage problems.

CO₂ 압축기의 운전조건과 오일토출의 상관분석에 관한 실험적 연구

이익수(Ik Soo Lee),강병하(Byung Ha Kang) 대한설비공학회 2011 설비공학 논문집 Vol.23 No.1

A portion of oil for lubrication of compressor flows together with refrigerant in the refrigeration system. If the oil discharge from a compressor is increased in the refrigeration system, not only pressure drop is increased in other components, such as evaporator and gas cooler, but also heat transfer coefficient in the heat exchangers is decreased. Oil discharge rate from a compressor may strongly depend on operating conditions of a compressor. In this study, one stage single rotary compressor is employed for measuring oil circulation ratio(OCR). Carbon dioxide and PAG oil are used as refrigerant and lubricant. Using a U-tube densimeter, mixture density is measured. Oil circulation ratio(OCR) can be estimated by measured mixture density. The results obtained indicate that the oil circulation ratio(OCR) is increased as the suction temperature or compressor operating frequency is increased. Oil circulation ratio(OCR) correlation of the compressor is also suggested.