妊娠時尿中 17-ketosteroids 및 17-hydroxycorticosteroids 値의 動態에 關하여

손창수 서울大學校 大學院 1969 국내석사

고정상 여재를 적용한 A^(2)/O 공정내 미생물 Floc과 EPS(Extracelluar Polymeric Substance)에 관한 연구

손창수 연세대학교 대학원 2002 국내석사

현재 고도처리공정에 대한 많은 연구가 수행되어 왔으며, 부착성장을 이용한 공정이 개발되면서 생물막과 floc의 구조에 대한 근본적인 의문이 제기되었다. 특히 고농도의 생체량을 부착시킬 수 있는 여재의 적용으로 인하여 floc의 구조상에 어떠한 변화가 발생하였는지에 대한 다각적인 접근이 시도되어 왔으며, 현재도 이러한 분야에 대한 연구가 활발히 진행되고 있다. 특히, 생물막은 단지 폐수나 하수처리 시스템뿐만 아니라, 생태적인 관점에서도 중요한 인자로 고려되기 때문에 더욱 관심의 대상이 되고 있다. 본 실험에서는 A^(2)/O공정의 포기조에 고정상 여재(DSBB)를 충진하여 미생물 floc의 변화과정을 관찰하였다. 이 과정을 통해서 생물막을 구성하는 고밀도의 미생물 floc과 부유 성장하는 floc의 근본적인 차이점을 EPS라는 가교인자(bridging factor)를 이용하여 설명하고자 하였다. 그리고 슬러지의 침전성과 EPS의 양이 전체적인 시스템의 처리효율에 미치는 영향을 분석하여 floc이 처리효율에 미치는 영향을 간접적으로 추정해 보고자 하였다. A^(2)/O공정을 적용하여 실험한 결과, 여재의 최적 충진율은 30%(v/v)임을 알 수 있었고 다양한 EPS의 추출방법 가운데, 본 실험에서는 EDTA(ethylenediaminete tra acetic acid)와 원심분리를 혼합한 추출방법을 이용하였다. 본 추출방법을 이용한 실험에서 protein의 성분은 미량으로 존재하였으며, EPS의 주성분은 DNA와 polysaccharide임을 알 수 있었다. 이 사실로 미루어 보아, 추출방법과 미생물의 종류에 따라 EPS의 추출성분에 변화가 발생한다는 사실을 추정할 수 있었다. 그리고 생물막을 구성하는 floc과 부유성 floc의 EPS성분 가운데, DNA성분이 가장 큰 차이점을 보인다는 사실을 확인할 수 있었다. 또한, 인성분(P)이 가장 EPS의 추출에 가장 제한적인 인자임을 알 수 있었고, 처리효율과 비교해본 결과, EPS의 추출량은 COD, P보다는 N의 제거효율과 비교적 상관관계를 가지고 있음을 추정 할 수 있었다. Recently, many studies about BNR(Biological Nutrient Removal)s have been performed and the development of new processes including various media has resulted in the fundamental question about the structures of both biofilm and floc. The application of media having an ability to attach many biomass have led to the various approaches looking into the structural change of microbial floc and the study about this section is being carried out currently. In addition, because biofilm is considered as the important factor at the ecological aspect as well as wastewater treatment system, many researchers is more having interests in this part. The focus of this study is to chase the change of microbial floc after including fixed media(DSBB) in the aerobic reactor of A^(2)/O process. Therefore, it was intended that the difference between microbial floc comprising biofilm and suspended microbial floc was evaluated by EPS, a bridging factor connecting many bacteria. Also, through analyzing the influence that settleability and EPS of sludge had on the efficiency of this process, I intended to estimate the influence that the floc had on removal rate of organic matter and nutrients(N,P). As a result of this study, the optimal value of media portion in this reactor was 30%(v/v) and out of various EPS extraction methods, the mixed extraction method using EPS and centrifugation was applied in this study. Usually, it is aware that EPS components is protein, polysaccharide, DNA. In this study, the evidence suggest that protein is a trace element and the major components of EPS is DNA, polysaccharide. From this consequence, it was estimated that EPS components vary with extraction methods and microbial species. And it was ascertained that in two types of floc, namely, biofilm and suspended floc, DNA was the most different factor in EPS components. Furthermore, it was suggested that phosphorus is the most limiting factor in the process of extracting EPSs and the removal rate of nitrogen components are having more correlations with the amounts of EPS than that of COD, phosphorus etc are.

THE DEPOSITIONAL CHARACTERISTICS IN THE BAY-MIDDLE AREA OF THE GOMSO BAY TIDAL FLAT, SOUTHWESTERN COAST OF KOREA

손창수 전남대학교 2002 국내석사

The Gomso tidal flat, located in the southwestern Korean Peninsula, is characterized by wave-dominate, funnel-shape. The leveling, distribution of sedimentary facies, sedimentary structures and sedimentation rate are performed to establish the sedimentary environment of middle area in Gomso Bay intertidal flat during 1999. Tides in Gomso Bay show the semidiurnal type with a mean tidal range of 4.3 m. Several sand shoals are located in the lower tidal flat. The inner part of Gomso Bay has developed tidal creeks. The trend of surface sediment faceis in the inner and middle areas of Gomso Bay is seaward coarsening. Such distribution pattern is similar to other tidal flats in the western coast of Korea (Kim and Park, 1985; Lee et al., 1985). The outer flat of Gomso Bay, however, shows seaward fining trend in summer. The mean value of sedimentation rate is -2.3 mm/month in the middle flat, whereas 8.5 mm/month in the lower flat. In the middle flat, deposition occurs in summer and erosion occurs in fall. Deposition and erosion are alternated in winter season. In the lower flat, deposition occurs continuously except typhoon. The structures are different in each facies. In the middle flat, disorganized gravels and thick shell bed (10-15cm) are shown nearby shoreline. The gravels and shell bed would be not natural but artificial structures. The observed structures are small-scale ripple cross-lamination, parallel-lamination and shell fragments. The primary structures are disturbed by bioturbation. It is dominant on the whole. In the lower flat, large and small-scale ripple cross-lamination, erosional surface and parallel lamination are dominant. Occasionally, shell bed is developed. Trough-cross lamination is mostly dominant and herring-bone cross-lamination is sometimes found in cross-laminations. Bioturbation exists as a whole, but the intensity is slight. Parallel lamination is alternated with cross-lamination. On the whole, large- and small-scale ripple cross-lamination, erosional surface, biturbation and parallel lamination are dominant, whereas flaser bedding, wavy bedding and lenticular bedding, tidal flat, are very rare, as compared with intertidal flat protected by barrier island such as those of North Sea and eastern North America. 한국 서남해안에 위치하고 있는 곰소만 조간대는 파랑이 우세한 개방형 만의 특성을 띄고 있다. 본 연구를 위하여 1999년 동안 고도측정과 표층퇴적물분포, 퇴적구조 및 퇴적률 등을 측정하였고 2000년 여름에 공간분포를 실시하여 곰소만 조간대 중앙부에서의 퇴적환경을 조사하였다. 곰소만 조간대는 평균 4.3 m의 조차를 가지는 대조차 환경으로 조석은 일조부등 (diurnal inequality)이 거의 없는 1일 2회조로서 평균조차를 433.8 cm (대조차: 589.8 cm, 소조차: 277.8 cm)이고, 최대조차는 717.4 cm에 달한다 (국립지리원, 1981). 하부조간대에는 소량의 조간대 사주가 위치하고 있으며, 내만에는 조류세곡이 발달하여 있다. 곰소만 조간대의 내만역과 중부역에서는 일반적으로 외해 조립의 경향을 나타내는데 이는 한국 서해안에 있는 다른 조간대와 유사한 경향을 나타내고 있다. 그러나 외만역에서는 내만역과는 달리 외해 세립화 경향을 나타내고 있다. 곰소만 조간대의 중부지역에서는 퇴적률은 중부조간대에서는 -2.3 mm/month의 퇴적률을 나타내는 반면 하부조간대에서는 8.5 mm/month의 퇴적률을 나타낸다. 중부조간대에서는 여름에는 퇴적이, 늦여름에는 태풍으로 인한 침식이 일어나며 겨울에는 침식과 퇴적이 반복적으로 일어난다. 하부조간대에서는 여름철 태풍을 제외하고 지속적인 퇴적이 일어난다. 퇴적구조는 중부조간대에서 무구조의 조립질퇴적물과 패각층이 연안근처에서 나타나며 이러한 퇴적물들은 인위적인 현상에 의해서 나타나는 구조들로 사료된다. 또한 소규모의 사층리와 평행엽층리, 패각층이 관찰된다. 대부분의 일차구조들은 생물교란작용에 의하여 심하게 파손되어져 있다. 하부조간대에서는 대형, 소형의 연흔사층리구조 (ripple cross-lamination)와 평행엽리구조 (parallel lamination), 침식면과 패각층등이 우세하게 관찰되며, 북해나 북아메리카에서 흔히 관찰되는 플레이져층 (flaser bedding), 파동형층리 (wavy bedding), 렌즈상층리 (lenticular bedding) 등은 거의 관찰되지 않는다. 퇴적구조에서 나타나는 계절변화로는 중부조간대의 하부지역에서는 여름철에는 모래질 실트지역이 겨울철에는 모래 내지는 실트질 모래의 퇴적상으로 조립해짐을 알 수 있다. 또한 중부조간대의 상부지역에서는 겨울철의 폭풍의 영향으로 세립질 퇴적물 위에 조립질 퇴적물이 쌓여 있음이 관찰되며 이러한 조립질 퇴적물들은 여름철과 가을철로 갈수록 생물교란작용을 받아 1차 퇴적 구조들이 심하게 파손되어 있음을 알 수 있다.

통일 이후 남북한 군사력 통합방안 : 분단국의 군사통합 사례분석을 통한 통합방안

손창수 연세대학교 정경대학원 2014 국내석사

랜덤媒質을 通過한 光波의 統計的 性質에 관한 硏究

손창수 東亞大學校 大學院 1998 국내박사

자연 또는 인공적인 매질이 시간과 공간적으로 랜덤하게 변화할 때 전파되는 광파의 진폭이나 위상은 굴절이나 회절 등에 의해 랜덤하게 변화한다. 이러한 매질을 통과한 전자파의 통계적 성질은 천문학이나 통신 또는 의용공학 등의 분야에서 많은 관심을 가지고 있다. 최근 30여년간 랜덤매질을 통하여 전파되는 전자파에 관한 연구는 계속되고 있지만 랜덤매질내에서 전자파의 특성은 완전히 이해되지 않고 있다. 랜덤매질에서 광파의 광도 변동에 대한 중요한 통계적 성질중의 한가지는 광도의 확률분포 p(I)이다. 현상학적 모델들로 부터 얻어진 여러 가지 분포함수들이 p(I)에 대한 가능성이 있는 분포로서 제안되어 있다. 본 논문에서는 대기와 같이 연속적인 분포를 가지며 약한 굴절율변동을 가진 랜덤매질을 통과한 광파의 통계적 특성을 연구하였다. 랜덤매질에 의한 광파의 위상변동이 한계치보다 커서 광도변동이 심한 랜덤포커싱 영역에 특히 관심이 있으며 아직까지 이 영역에 대한 광도의 확률분포는 잘 알려져 있지 않다. 랜덤매질을 통과한 광파의 광도변동에 대한 데이터를 얻기 위해 수치 시뮬레이션을 이용하였다. 랜덤매질은 Pack 및 do Wolf에 의해서 제안된 단순화된 랜덤모션모델을 사용하였으며 관측면에서의 광도의 계산은 호이겐스-프레넬 각-스펙트럼 표현식을 이용하였다. 그리고 모멘트법, 히스토그램법, χ^(2)-테스트 등을 이용하여 시뮬레이션으로 부터 얻어진 광도데이터를 제안된 확률분포와 비교하여 각 분포함수의 적합성 여부를 조사하였다. 그 결과 IK분포를 포함한 대부분의 확률분포들은 광도변동이 적은 영역에서 적합성이 좋았으며, 광도변동이 큰 영역에서는 IK분포를 제외한 나머지분포들은 잘 맞지 않음을 알 수 있었다. 적합성여부를 판단하기 위해 통상 χ^(2)-테스트나 모멘트법 중의 하나만 사용되어 왔으나, χ^(2)-테스트는 광도변동이 큰 영역에서, 그리고 모멘트법은 광도변동이 작은 영역에서 취약점이 있으므로 두가지 방법을 병행하는 것이 필요하다. When natural or man-made media vary randomly in time and space, the resulting phase and amplitude of light wave propagating through such turbulent media fluctuate randomly due to reflection and diffraction. Even if electromagnetic wave propagation through random media has been studied for about 30 years, yet the behavior of electromagnetic waves in random media is not fully understood. One of the important statistical quantities for irradiance fluctuation of light wave in the random media is the probability distribution p(I) of irradiance. From phenomenological models, several distribution functions have been proposed as possible candidates for p(I). Statistic characteristics of light wave propagating through random media with continuous distribution and weak fluctuation of reflective index such as the atomsphere are studied in this paper. We are especially interested in the random focusing region, for which probability distribution of irradiance is not well known. Irradiance data though random media is obtained by numerical simulation. And then the validity of each distribution function is tested by comparing the proposed distribution functions with simulation data, using the moment method, the histogram method and the x^(2)-test. Random medium is realized instantaneously by using simplified version of random motion model proposed by Pack and de Wolf. In order to calculate the irradiance of light wave at receiving points, the well-known angular-spectrum representation of Huygens-Fresnel diffraction formula is used. When irradiance fluctuation is not so large, almost all of the proposed distribution functions show good fitness. In the random focusing region, where the scintillation index is greater then 1, only the IK distribution is in good agreement with irradiance data. When testing the goodness-of-fit of a probability distribution function, one of the two method, i. e., either the x^(2)-test or the moment method, is usually used. However, the x^(2)-test has a weakness in the region of large irradiance, and the moment method has a drawback in the region of small irradiance. It thus seems necessary that both of the methods are used simultaneously for accurate test of probability-distribution models.

3演算 增幅器로 構成한 低感度能動필터 設計에 관한 硏究

손창수 東亞大學校 大學院 1981 국내석사

A construction method of low sensitivity active filter using three operational amplifier is proposed and tested. The results from theory and experiment are as follows; 1. The effects of operational amplifiers as active devices on the sensitivity of constructed active filter are relatively large. 2. The sensitivity of the filter is better as number of terms associated with the time constant τ of operational amplifiers in the denominator polynomial of the transfer function decreases.

유연체 해석을 이용한 엔진블록의 동응력 해석에 관한 연구

손창수 창원대학교 대학원 2009 국내석사

The dynamic stress of the diesel engine block is analyzed using flexible-body dynamic analysis. Multiple loadings including the pressure load due to gas combustion, thermal load, and dynamic load are considered. Thermal load is assumed constant, however, pressure load and dynamic load are treated as time dependent. The present work is focused on the dynamic stress analysis, especially on finding critical points of the engine block. The analysis model includes four parts·engine block, generator, bed, and mounts. On the other hand, crank shaft, pistons, and main bearings are excluded from the model. However, their dynamic effects are applied by dynamic forces, obtained in the separate analysis. Dynamic stress is found by using flexible body dynamic analysis, and compared to the measured data.

專門大學生의 中途脫落 要因 分析에 關한 硏究 : 동원대학을 중심으로

손창수 한경대학교 2009 국내석사

The aim of this study is to analyze the factors influencing the college students' dropping out of the college. This study provides an analysis of the college dropouts in recent four years and a preventive measure for them. As a result of this study, 1st year male students compared with 1st year female students and 2nd year students tend to give up their studies easily. It is also found that the students on leave of absence tend to eventually drop out. It is also found that withdrawal from school occurs mostly in March. And it is found that the students who got a scholastic warning tend to leave the school more easily than the students who didn't. The students who got scholastic warning tend to leave the school voluntarily or get expelled from the school without enrolling. It is found that the students who took the leave of absence due to the poor scholastic achievement tend not to return to the school. Therefore, we may consider the students with poor scholastic achievement, like the students who took the leave of absence, as would-be dropouts. In the analysis of the reasons for leaving the school, it is found that the dissatisfaction with their majors or departments usually makes them to cram to repeat entrance exams, to enter other colleges, or to act badly in studying majors. The dissatisfaction tend to be greater reasons for withdrawal from the school than home environment, personal reasons, or economic reasons. It may be concluded that we should try to bend our efforts in guiding the freshmen with concern and counselling, finding measures in preventing long-term absences, and developing new programs helping the students to continue their studies rather than taking the leave of absence in order to reduce the number of dropouts.

인코넬 718 내열합금의 고속가공특성 평가

손창수 부산대학교 대학원 1998 국내석사

The high speed machining is one of the most effective technology to improve productivity. Due to the high speed and the high feed rate, high speed machining can give great advantages for the machining of dies and moulds. But determination of cutting condition is very difficult, because cutting mechanism of high speed machining is very complicated, especially in using ball end-mill. Recently research for high speed machining of Difficult-to-cut material is studied by many researcher. and especially Inconel 718 is one of the most difficult workpiece for machining, So it is necessary to evaluate the machining characteristics of Inconel 718. In this study, high-speed milling for Inconel 718 was carried out with TiN coated tungsten carbide and TiN coated High speed Steel ball endmill. High speed machining of this material was carried out with TiN coated WC ball endmill and TiN coated HSS ball endmill. The cutting force and shape of machined surface and chip type were investigated according to variation of cutting speed, feed rate and depth of cut.

Customer Evaluation of Internet-based Service Quality and Intention to Re-use Internet-based Services

손창수 Southern Illinois University 2000 해외박사

In the early stage of Internet markets, Internet-based companies competed with traditional companies by selling products and services at lower prices. Since Internet-based companies can provide lower prices, they could get a competitive advantage in the market. Today, more and more companies participate in Internet markets, which brings about more intense competition in Internet markets. Hence, they cannot compete on the basis of low prices. Low prices have become a "qualifier" in Internet markets. They need an "order-winner" in order to attract customers to their web sites and make them loyal customers. In addition, Internet-based companies do not compete with traditional companies, but mainly with other Internet-based companies. Thus, what becomes important is "service." Therefore, this study views service from the customer's perspective and raises two research questions: "How do customers evaluate the quality of Internet-based services?" and "If customers can evaluate the quality of Internet-based services, is the perceived service quality critical in explaining customer's intention to re-use Internet-based services?" In order to examine these research questions, a research model is proposed based on literature review, focus group, manipulation of traditional service quality measure, and inputs from Internet-based companies. The proposed research model is verified using questionnaire survey data from customers who have experience of Internet-based services. Data analysis reveals six valid and reliable dimensions to measure perceived service quality. They are Trust, Customized Communication, Ease of Use, Web Site Contents and Functionality, Reliability, and Speed of Delivery. Subsequently, multiple regression analysis suggests that perceived service quality is a most influential component in explaining customers' intention to re-use Internet-based services. Low cost is also important, although low cost is less important than perceived service quality. Thus, for Internet markets, low cost is a qualifier while the order-winner is perceived service quality. Therefore, Internet-based companies have to focus on improving service quality while lowering cost. This study extends service quality measures developed in traditional markets to Internet-markets. In addition, the developed service quality measures provide diagnostic and descriptive tools for Internet-based companies to improve service.