시뮬레이션에 의한 投資分析

河正鎭,徐洵根,趙吉福 동아대학교 공과대학 부설 한국자원개발연구소 1987 硏究報告 Vol.11 No.1

In general, there are two methoes which investment proposals can be evaluated, one is deterministic approaches using single value or best estimates for the magnitude of returns and the other is pobabilistic approaches which involve probabilistically based analytical procedures and Monte Carlo simulation. The advantage of the method reflects much of reality more comprehensive than the former. This syudy estimates cumulative probabilistic distribution of internal rate of return and net present value using Monte Carlo simulation by combining variables; project cost, sales volume, unit sales price, operating cost and etc. The descriptive methods for discrete cash flows is proposed for use in economic risk analysis and numerically illustrated by microcomputer aided solution procedure. Further, to grasp the effect on the investment by variables, sensitivity analysis is carried out.

의사결정 방법에 의한 철근콘크리트 구조물의 상태평가

박길현,황선화,유동원 朝鮮大學校 建設技術硏究所 2006 建設技術硏究 Vol.26 No.1

In this study, a method based on the Analytic Hierarchy Process for systematizing the maintenance and securing the safety of the reinforce concrete bridges using an appearance inspection and state evaluation was proposed. It would be possible for general structure engineers to appraise the bridges with this method. Results from periodical inspections are mostly qualitative because of the inspector's subjective judgment. Therefore, for more objectivity of the results from the safety inspections. quantitative standardization processes of the appraisal items areessentially required. Properties of the selected items were standardized with reference to the existing research results and actual data. As for the item thatis difficult to represent quantitatively, word variable of the Analytic Hierarchy Process was introduced and standardized so that the objectivity of the subjective valuation was acquired. Results from this study are as followed. It is possible to acquire very reliable appraisal results of the reinforce concrete bridges according to the Analytic Hierarchy Process defined in this study. Result from this study can be applied practically through the application and analysis of the appraisal technique and the procedure with actual data. Verification through the practical uses and improvements are required for the development in this field.

저장기간에 따른 검정콩 종피의 안토시아닌 함량 및 색차

정길웅,주용하,이동진 한국국제농업개발학회 2004 韓國國際農業開發學會誌 Vol.16 No.2

검정콩이 가지고 있는 안토시아닌 색소의 안정성을 간접적으로 평가하기 위하여 재배품종 중 검정콩2호, 일품검정콩, 청자콩, 다원콩, 진주1호, 쥐눈이콩을 공시하여 실온에서 저장 기간(0, 6, 9, 12개월)별로 검정콩 종피의 안토시아닌 함량 및 색차의 변이를 조사하여 기능성 검정콩의 품종육성 및 저장에 대한 기초 자료를 얻자 실험한 결과는 아래와 같다. 1. D3G는 저장후 6개월까지는 약간 증가하였다가 9개월 이후 다시 감소하였으며, C3G는 저장후 기간이 경과함에 따라 계속 감소하였고, Pt3G는 저장 9개월후부터 감소하였다. 총함량도 저장후 기간이 경과함에 따라 계속 감소하였다. 2. 안토시아닌 색소의 Hunter's value인 L, a, b를 조사한 결과, 명도는 저장당시부터 6개월까지 감소하였으나 그 이후 12개월까지 큰 차이가 없었으면, 적색도는 저장후 9개월까지 증가하다가 이후 큰 차이를 보이지 않았고, 황색도는 저장 이후 12개월까지 점차적으로 증가하였다. This experiment was conducted to investigate the difference of anthocyanin content in black soybean seed coat according to different storage periods. Cultivars used in the experiment were six cultivers such as llpumgeomjeongkong, Geomjeongkong #2, Cheongjakong, Jinju #1, Dawonkong, and GuinuniD3G (delphinidin-3-glucoside) had increased little by little up to six months after seed storage and then decreased up to twelve months after nine months. C3G (cyanidin-3-glucoside) had continuously decreased from seed storage to twelve months. Pt3G (petunidin-3-glucoside) was not different up to nine months after seed storage but had decreased up to twelve months after nine months. TA (total anthocyanin) had slightly decreased up to twelve months after seed storage. The content of individual and total pigof anthocyanin had all decreased according to long storage of seeds and decreasing tendency was different among D3G, C3G, Pt3G, and TA. As a result of investigation for L, a, b as Hunter's value of anthocyanin contents, L had decreased from seed storage to six months and then that later was no difference up to twelve months. a had slightly increased up to nine month after seed storage and then there was no difference from nine to twelve months. b had gradually up to twelve months after seed storage.

전류 비유 모델에 의한 초등학생의 전류 개념 변화 분석

유병길,강인석,김병철,남만희,박선희,소하연,윤희정,이영아,이하룡,전병문,정승호 부산교육대학교 과학교육연구소 2000 科學敎育硏究 Vol.25 No.-

There exists a major impediment to learning electricity which may illuminate why direct presentation of scientists' ideas is too aggressive a strategy. This impediment lies in thinking that electricity is used up and in envisaging the light bulb as a consumer. This view is based on a powerful idea which summarises much of our experience; it declares that 'things get used up', 'you cannot get something for nothing', and 'intuitive thinking'. To replace this view with scientific view, we made the analogy model. It is suggested that the analogy model is more effective in teaching electricity circuits than conventional teaching method.

R·C 교량의 외관상태에 관한 연구

박길현,황선하 朝鮮大學校 建設技術硏究所 2007 建設技術硏究 Vol.27 No.1

As the human material life style growth and the industrialization have been taking place, the overland transporting system also has been growing with its size, mass, and velocity. Especially, since domestic overland transporting system is rapidly growing, the smooth function of highway is very important in economic and military matters. To meet these requirements, the bridge's usage, safety, and durability have to be revaluated very carefully. But by focusing only on the quantity of the public basic facility has brought many tragedies to us. To prevent such incidents, there are many steps we can take such as careful planning, careful designing, careful constructing, using good materials, and steady maintenance; the most important thing is the maintenance.Taking all this in consideration, in this thesis ra like to construct a system related to the safety of ferroconcrete bridge according to fuzzyidea, and at the same time creating a scientific maintenance system would be very important to gain credibility from regular citizens.

균열밀도에 따른 R·C 슬래브 교량의 내하력 평가

박길현,양승현,황선하,정경덕 朝鮮大學校 建設技術硏究所 2003 建設技術硏究 Vol.23 No.1

Through the exterior features on reinforced concrete slab, crack density and crack originate deflections ratio crack density, decrease percentage of load carrying capacity, crack originate deflections ration and decrease percentage of load carrying capacity were statistically analyzed. Crack density, crack originate deflections ratio and decrease percentage of load carrying capacity are very closely related each other with 0.724, 0.821 and 0.317 of correlation coefficient within 95% of mind level. However, the correlation between crack originate deflections ratio and decrease percentage of load carrying capacity was low. Through the regression equation curve method in which crack density selected as independent variable, crack originate deflections ratio and decrease percentage of load carrying capacity as dependent variable, regression equations were presumed. Equations exist in mind level range of F(0.05, S-curve showed the highest, conformance with 79.5%, 72.2%. The regression equation between CRD or LCCD and CD was also shown. The overall judgement of load carrying capacity of bridges can be possible through the moreover investigation of crack density, the time needed precision could be valuable data for lower maintenance cost, the degree of deterioration of bridges and safety judgement.

초등학생들의 에너지와 관련한 사전개념 조사

유병길,소하연 부산교육대학교 과학교육연구소 2000 科學敎育硏究 Vol.25 No.-

Energy, one of the most important themes in science education, is also one of the most difficult. Many students often confuse colloquial vocabulary and everyday ideas wih scienctific definitions and concepts. The present work uses a questionnaire including picture to probe elementary student's conception concerning energy, and compare their prevalence in students of different grade groups. Analysis of the data shows that they relate energy with states concerning electricity and energy source. It is suggested that, concerning energy teaching, it is better to begin with electric energy transformation to other energy.

運動處方을 通한 Swimming 訓練이 有酸素性作業能力 및 呼吸循環係에 미치는 影響(Ⅰ)

鄭吉商,河星 동국대학교 경주대학 1998 東國論集 Vol.17 No.1

This essay explores the results of a Graded Maximal Exercise Test, as measured by a ramp exercise test. The test was administered following a prescribed swimming regimen, for a duration of 12weeks. The subjects were composed of 8 University Department of Physical Education majors, with an average age of 18.9 year. The objective was maximal exercise, with physical intensity levels of VO_2max of 40%, 60% and 80%. When compared to initial scores, subsequent scores reflected the following changes ; 1) V˙O_2max(㎖/㎏/min) demonstrated a remarkable increase of 16.2% in All-out, with subsequent ratings of 80%, 60% and 40%. V˙O_2max showed a marked tendency to increase subject to an increased exercise intensity and duration. 2) Minute Ventilation showed a considerable increase(30.9%) in All-out and 80% based on intensity(4.5%) of V˙O_2max. It also demonstrated a slight increase in exercise intensity. There fore, the differences between them was not illustrated. 3) Respiratory rate elicited response rates of 4.6% and 22.5% in All-out and in stability, respectively. Otherwise, a minor increase of less than 2% was demonstrated in exercise intensity. In conclusion when considering a prescribed exercise regimen as a menas of improving aerobic work capacity, one must note that minor gains can be realized in low intensity(40%) training, but that more dramatic gains can be made in the realm of high intensity training. Therefore, the intensity level must be carefully considered when developing an exercise regimen.

균열밀도에 따른 RC교량의 내하력 평가 및 수명 예측

박길현,황선화,박종환 朝鮮大學校 建設技術硏究所 2006 建設技術硏究 Vol.26 No.1

There are several causes, the Percussion from the exterior, the decline of capacity by circumstances, the crack occurred in the interior, the carbonation and soon, that can shorten the span of the concreted construction. And crack density of bridge structures gets higher when they are deteriorated because the concrete crack is the problem of usability. Higher crack density cause the higher bending moment and lower load carrying capacity. In this reason, crack investigation was executed to understand the relation among the degree of degradation caused by the crack occurred on reinforced concrete structures and deflections ratio and load carrying capacity. Deflections ratio and decrease percentage of load carrying capacity of the structures were statistcally analyzed when medium crack which has crack width over O.lmm generated. However, the crack itself, as the primary factor of the life-curtailment of concreted construction, is principal and should bring about the erosion of the reinforcing rod and the span of life.

검정콩의 종자크기 및 자엽색에 따른 안토시아닌 함량 및 색차

주용하,정길웅,이동진 한국국제농업개발학회 2004 韓國國際農業開發學會誌 Vol.16 No.3

재배품종인 검정콩2호, 일품검정콩, 검정옥콩, 청자콩, 다원콩, 진주1호, 쥐눈이콩(Y), 쥐눈이콩(G)를 공시하여 종자크기 및 자엽색에 따른 안토시아닌의 함량 및 색차를 알아보고자 수행한 결과는 다음과 같다. 1. D3G, Pt3G 및 총함량은 소립종에서 높았으며, C3G는 대립종과 소립종간에 차이가 없었다. 2. 대립종과 소립종간에 안토시아닌의 색도는 Hunter's value 인 L(명도). a(적색도), b(황색도)값이 모두 차이가 없었다. 3. D3G와 Pt3G는 녹색자엽종의다 황색자엽종에서 높았으며, C3G와 총함량은 황색자엽보다 녹색자엽종에서 높았다. 4. 황색자엽종과 녹색자엽종간에 안토시아닌의 색도는 Hunter's value인 L(명도), a(적색도), b(황색도)값이 모두 차이가 없었다. To proffer the basic data about varietal breeding for specific use through investigation of the content and color difference of anthocyanin due to seed sizes and cotyledon colors. Eight varieties, Geomjeongkong 2, Ilpumgeomjeongkong, Geomjeongolkong, Cheongjakong, Tawonkong, Jinju 1, Juinunikong-Y, and Juinunikong-G were tested in this experiment. Delphinidin-3-glucoside (D3G), petunidin-3-glucoside (Pt3G), and total content of anthocyanin were higher in small seeds but cyanidin-3-glucoside (C3G) was not different between seed sizes. Color difference of anthocyanins between large and small seeds was no distinguished difference in L (lightness), a (redness), and b(yellowness) as Hunter's value. D3G and PT3G in seed cotyledon color were higher in yellow color than green color and C3G and total content were higher in green color than yellow color. The L, a, and b of anthocyanin between seed cotyledon colors were all not different.