• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.823-833
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• 1997

To clarify the annual reproductive cycle of the banded catfish, Pseudobagrus fulvidraco (Richardson), the seasonal changes in histological aspect of gonad and liver were examined. The adult fish was raptured from the upper stream of Young-San river, Chunnam in each month from May 1992 to June 1993. Based on the annual changes in GSI (gonadosomatic index), HSI (hepatosomatic index), CF (condition factor) and histological aspects of the gonads, the annual reproductive cycle were classified into 5 periods as follows: 1) Growing phase (from April to early May): The value of GSI increased and the size of oocytes in perinucleolus stage in oocytes increased gradually. Spermatogonia were developed actively from the epithelial tissues of seminiferous tubules. 2) Maturing phase (from Hay to early June): GSI levels increased rapidly in both sex. Oocytes at various developmental stages were observed. Appearance of active spermatogenesis were observed. 3) Mature and spawning phase (from June to August): High values of GSI remained static and oocytes accumulated significant quantitis of yolk globules. 4) Degenerating phase (from September to November): GSI levels decreased and ovaries were filled mostly with oocytes at the perinucleolus stage. Hepatic cells accumulated significant amounts of lipid droplets. 5) Resting period (from December to March) : Low values of GSI were kept and the size of oocytes at the perinucleolus stage did not increase. Spermatogenesis was not observed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.227-231
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• 1984

Chinese CGMS (Cytoplasmic-Genetic Male Sterility) is being transfered to Korean cultivars which will be used as CGMS maintainers. These maintainer lines along with the Chinese CGMS lines and their maintainer lines were crossed with another group of Korean cultivars which will be used as the fertility restorers, and their yield heterosis were examined. The yield heterosis was calculated as high as 113.0-221.1 % in terms of heterosis (F$_1$/Midparent) with the grand mean of 150.5%, and, 86.1-179.8% in terms of heterobeltiosis (F$_1$/better parent) with the grand mean of 125.3%. Among the female parent groups, Chinese mainteiners were the highest following by Chinese MS lines and the Korean maintainers were the lowest. Heterobeltiosis of yield components were 92.7%, 120.0%, 103.0% and 112.0% for number of panicles/unit area, number of grains/panicle, fertility per cent and 1000 grain weight, respectively. Path-coefficients of yield components to the yield were calculated. The highest one was number of grains per panicle ranging 0.8073-0.8649 followed by the 1000 grain weight ranging 0.2000-0.5032. The grain yield ratios to the grand mean were calculated in terms of combining ability. It was highest with the Chinese maintainers followed by Chinese MS lines and The Korean maintainers were lowest. This facts bring cautions to the breeding efforts to transfer the Chinese CGMS in to Korean maintainers.

• Journal of Chest Surgery
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• v.34 no.2
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• pp.111-117
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• 2001

배경: 심근 수축력과 더불어 전신저항은 개심술 후 적절한 심박출량을 유지하기 위한 매우 중요한 요인이다. 후부하의 변화를 비관혈적으로 평가할 수 있는지 알아 보고자 대동맥 혈류파형의 변화를 관찰하였다. 대상 및 방법: 개흉한 8마리의 잡견에서 연속파형 Doppler 심초음파를 이용하여 nitroprusside 단독 또는 epinephrine과의 병합투여 잔후로 상행 대동맥 혈류를 측정하였다. 결과: Nitroprusside의 투여로 동맥압과 전신저항은 약물의 투여량에 비례하여 감소함으로써(p<0.05 vs 기준치), 대동맥 혈류파형의 최고속도, 평균가속 및 분거리(속도시간적분$\times$심박동수)는 증가하였고, 가속시간은 짧아졌으며(p<0.05 vs 기준치), 가속시간/박출시간의 비는 변화가 없었다. Nitroprusside 투여로 인한 전신저항의 변화는 속도시간적분이나 Doppler 시간간격 지표보다는 최고속도(r=0.60, p=0.001)와 평균가속(r=0.52, p=0.003)과 상관관계가 있었다. Epinephrine과의 병합투여로 전신저항이 증가하지 않는 한 nitroprusside 단독투여에 비해서 최고속도, 평균가속 및 속도시간적분이 더 크게 증가했으나, 전신저항이 증가되면 이 Doppler 지표들은 감소하는 경향을 보였다. 결론: Doppler 심초음파를 이용하여 상행 대동맥 혈류파형의 최고속도와 평균가속을 연속적으로 측정함으로써 후부하의 변화를 비관혈적으로 평가할 수 있으리라 생각된다.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.111-117
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• 2011

In this paper, proposed client virtualization technology to minimize degradation of the local computing environment, efficient and qualified users in the area of virtual functions needed to enable the user to provide important information in the local computing environment protection and performance, stability and continuity was important to keep. As well as the local computing environment from malicious code attacks such as methods for protecting virtualized domain also can not be overlooked as a major problem area in a virtualized, virtualized data through the encryption of user-space security, maximized. In addition, through virtualization using local computing resources efficiently while still a local computing system separate from the computing resources to a single user can get the same effect.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6C
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• pp.609-614
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• 2003

In this paper, a new filter structure to improve frequency response characteristics in CIC(Cascaded Integrator-Comb) decimation filters is proposed. Conventional filters improve passband characteristics, but they make worse aliasing band characteristics. In this paper, we propose a new filter which is called IFOP(Interpolated Fourth-Order Polynomials). By using this proposed filter, passband droop and aliasing band attenuation are simultaneously improved. Since proposed filter needs only one multiplication, computation is not much. And overall linear phase characteristics are maintained since the proposed filter is also linear phase. Finally, implementation cost of the proposed filter is compared with those of conventional filters.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.353-353
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• 2020

기후변화에 적응하기 위해 많은 나라들이 수자원 관리 전략을 마련하고 있으며, 대체 수자원 활성화 방안에 관심을 기울이고 있다. 본 연구에서는 대체 수자원 활성화 방안 중 빗물 저류지의 용량 결정 방법을 제시하고자 한다. 빗물 저류지의 용량을 결정하기 위해 메타 휴리스틱 방법 중 하나인 입자 군집 최적화(particle swarm optimization; PSO)를 선정하였다. 이는 기존 실제 설계에 사용되고 있는 시행착오법보다 시간을 단축시킬 수 있다. 최적화 모형은 python의 pyswarm package를 이용해 구성하였다. 모형의 입력자료는 저류지 유입량과 목표 공급량, 목표 보장률이고, 목적함수는 빗물 저류지 용량의 최소화이다. 제약조건은 모의된 보장률이 목표 보장률 이상을 달성하는 것이다. 여기서, 보장률은 전체 모의 기간 중 목표 공급량을 공급한 기간의 비율이다. 제시한 방법론의 적용성을 검토하기 위해 실제 저류지가 설계된 인천의 청라지구 1공구를 선정하여 적용하였다. 최적화 모형의 입력 유입량은 SWMM으로 산정된 1995년부터 2004년까지의 유출량이며, 목표 공급량은 실제 설계에 활용된 용수 목적별 요구 수량이다. 여기서 용수 목적별 요구 수량은 대상지역의 노면 청소수, 화장실 세정수, 호수 유지수 등이다. 산정 결과 계산 시간은 약 30초 소요되며, 목표 보장률을 만족하는 저류지 용량이 결정되었다. 본 연구에 제시한 방법은 제약조건이 추가되어도 기존 시행착오법에 비해 간편함을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.106.2-106.2
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• 2010

동식물성 기름과 메탄올의 전이에스테르화 반응에 의해 생산되는 바이오디젤은 환경친화성과 지속가능성이 인정됨에 따라 그 생산량이 급격히 증가하고 있어 대두유, 유채유, 팜유 등의 원료유 부족과 가격 상승, 수급 불안정 등의 문제가 대두되고 있다. 이를 해결하기 위한 방안으로 유리지방산 함량이 높은 저가유지 자원(폐식용유, 폐돈지, 폐우지, soapstock, trapped grease)과 새로운 오일 작물을 이용한 생산 기술 연구가 활발히 진행되고 있다. 본 연구에서는 비활용 해외 열대작물 씨앗에서 착유한 식물성 오일을 정제하여 바이오디젤 원료유를 생산하는 과정에서 발생하는 폐기물(폐유, 폐수)의 경제적 처리 방안으로 유화유 제조 원료(벙커C유, 물)와 유화유 제조 첨가제(무기계, 유기계)로 활용 가능성을 검토하였다. 열대작물 오일의 물성 분석 결과 고형물, 수분, 인지질(phospholipid), 유리지방산(free fatty acid) 함량이 기존 원료유보다 매우 높게 나타났다. 인지질은 바이오디젤 제조 반응후 에스테르와 글리세린의 층분리를 방해하고 유리지방산은 염기촉매와 결합하여 지방산염을 생성해 생산 수율을 감소시킨다. 고형물과 수분 역시 촉매반응에 악영향을 가지나 여과와 감압증발에 의해 쉽게 제거가 가능하다. 유리지방산은 산촉매 에스테르화 반응에 의해 제거가 가능하다. 인지질은 탈검(degumming) 과정을 통해 제거하며 탈검은 수용성 탈검, 산 탈검, 세정 공정으로 구성된다. 착유한 원료유의 고형물을 제거 후 물과 수세하여 수용성 인지질을 수화하여 층 분리해 제거하고 상층의 오일은 추가적인 산 탈검을 수행한다. 그 뒤 세정을 통해 사용된 탈검제인 산과 추가적으로 수화된 인지질을 제거하게 된다. 이러한 3단계의 탈검 과정에서 하층으로 오일과 물이 폐기물로서 배출되며 본 연구에서는 배출 폐기물을 다시 층분리하여 오일층과 물 층으로 구분하여 유화유 제조에 사용되는 벙커C유, 물, 그리고 기존 유기계 및 무기계 유화제의 대체 가능성을 조사하였다. 유화 연료유는 기름과 물을 균일한 분산상으로 혼합한 연료유로 연소시 오일계 성분의 미연분을 감소시켜 연료 효율 제고와 배출가스 성상을 개선하기 위해 개발되어 왔다. 본 발표에서는 다양한 종류의 상용 첨가제 및 바이오디젤 원료유 생산 폐기물을 활용해 유화 연료유를 제조하였으며 각 유화유의 장시간의 상(phase) 안정성을 비교하였다. 바이오 폐기물 중에는 천연 계면활성제(surfactant)인 인지질이 다량 함유되어 있어 기존의 무기계 및 유기계 유화제보다 상 안정성이 우수하게 나타났으며 바이오디젤 원료유 생산 공정의 폐기물인 폐유과 폐수의 활용이 가능한 것으로 나타났다.

• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.224-231
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• 2002

Photoperiod (length of light per day) is a major factor in regulating reproductive function in golden hamsters. The information of photoperiod is transmitted to the reproductive endocrine system by melatonin. Thus the effects of melatonin aye investigated in male golden hamsters exposed to photoperiods. Paired testicular weights were markedly reduced in the animals housed in short photoperiod $(SP,\le{12\;hours\;day^{-1})$ and injected with melatonin in the evening, but not in long photoperiod $(LP,\le{12.5}\;hours\;day^{-1})$ and injected with melatonin in the morning. The histological examination of regressed testes showed reduction of tubular lumen diameter including the numbers of cells and Leydig cell number. The mean values of both follicle stimulating hormone (FSH) and luteinizing hormone (LH) were also lowered in the sexually inactive animals than in the sexually active animals. Melatonin receptor was identified by reverse-transcription polymerase chain reaction (RT-PCR) and its expression was examined in various tissues to scrutinize the action site of melatonin. It turned out 309 nucleotides and was definitely expressed in hypothalamus and pituitary including spleen, retina, and epididymis. And gonadotropin releasing hormone (GnRH) gene, which is a key element in regulating reproduction, was identified by RT-PCR but the expression of GnRH was not modified by the treatment of melatonin. Taken together, photoperiod via melatonin indirectly affects reproductive endocrine system, possibly through the release of GnRH, not the synthesis of GnRH.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2327-2331
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• 2011

The present paper relates to an analysis into patent applications by most exemplary patent-filing countries using time series analysis for a patented technology in which washing water in a water purifier is changed to magnetization hexagon water beneficial to human body, particularly the patented technology being to a magnetization hexagon water producing technology in which a magnetizer is mounted at an inlet pipe into which washing water is introduced to a water purifier, whereby the washing water is changed into magnetization hexagon water that is beneficial to human body for hygienic maintenance and use of bidet and toilet. In view of patent application trends in magnetization hexagon water producing technology fields, it can be easily noted from the analysis that a large portion of patent applications for the magnetization hexagon water producing technology comes from Korea and Japan, while USA and European countries are decreasing the number of patent applications and applicants. Therefore, there is a constant need of continuously observing the patent-filing trends in Korea and Japan in light of protection of patent rights in businesses that utilize the magnetization hexagon water. In view of the fact that many researches on and developments of products related to magnetization hexagon water are expected in the future, relevant producers and research institutes may effectively utilize the present paper in industrialization and patent research of the magnetization hexagon water.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.207-215
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• 2006

This study evaluated the effect of ultrasonic irradiation on reducing membrane fouling for the treatment of chemically treated leachate and biologically treated leachate. The experiments on improvement of membrane flux according to the membrane types(MF and UF) and membrane materials were performed with changing frequency(40 kHz and 120 kHz) and intensity(200 W and 400 W) of ultrasound in ultrasonic membrane separation apparatus which ultrasound can be periodically irradiated. Additionally, the effect of dual frequency ultrasound which 40 kHz md 120 kHz are irradiated simultaneously was evaluated. The improvement of membrane flux by periodical ultrasound irradiation was higher in microfiltration(MF) membrane than in ultrafiltration(UF) membrane. It was sustained more in the MF membrane of polyvinylidene fluoride(PVDF) than in that of polysulfon(PS). Ultrasonic improvement of membrane flux was different depending on the characteristics of target wastewater. It was sustainably maintained without reclogging using dual frequency ultrasound although the improvement of membrane flux was lower.