• 신재생에너지
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• 제16권2호
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• pp.35-46
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• 2020

Recently, turbines operating in hydro power plants are required to undergo renovation and modernization due to their age exceeding 30 years. In the process of renovation or modernization, a performance test of the scaled-down model is necessary to verify the performance of the real-size model. This model test method, with criteria that is similar to that of a real turbine, is the most economical and important method. Furthermore, the shapes of the runner and guide vane can be modified or replaced easily. However, during the process of modernization, the components with the spiral casing and draft tube are impossible to repair or replace because of the buried ground. Thus, in this study, numerical analysis is conducted to investigate the hydraulic performance based on the difference between the two-dimensional computer-aided design (CAD) shape and the real three-dimensional scan shape of the spiral casing and draft tube.

• International Journal of Human Ecology
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• 제9권2호
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• pp.93-105
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• 2008

This study investigates the different characteristics (mainly of community life) in representative intentional communities, between the ecovillage and cohousing, since the different purpose of the establishment of the community might result different characteristics. The study method is data analysis: the analysis material is Community Directory, A Comprehensive Guide to Intentional Communities and Cooperative Living (Rutledge, 2005). Of 750 listed communities, 397 (211 ecovillages and 186 cohousings) communities were analyzed. The findings of the study reveal that there are clear differences of community life between ecovillages and cohousings even though two communities are regarded as similar intentional communities. The similarities between the two communities are as follows: 1) Those mostly distributed in the USA, and established before 2000. 2) Dominant size of intentional communities is less than 20 residents and 20 houses. 3) They make decisions in consensus. 4) They eat together very frequently; at least once a week or more. 5) Shared work is required. The differences between the two communities are as follows: 1) They have different aims of establishment. For instance, ecovillage focus more on eco-living, while cohousing focuses more on the cohousing idea. 2) There are more female residents in cohousings than in ecovillages. 3) There are more cohousings in urban areas with a smaller area of land, contrary to that there are more ecovillages in rural areas with larger areas of land. 4) There are less identified leaders or leadership core groups in cohousing than in ecovillages. 5) Income sharing is more common in ecovillages than in cohousings. According to there findings, it is evident that a different purpose of establishment result in different characteristics of community life even though those belong to the similar category of the intentional community. Thus, it is recommended to adapt the correct characteristics that fit the aim of the community in the establishment an intentional community Topics and discussions about establishing intentional Topics and discussions abut establishing intentional communities could contribute to gather the intentional communities could contribute to gather the interests communities could contribute to gather the interests of residents as well as those of relevant civil-workers and administrators in Korea.

• 설비공학논문집
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• 제20권8호
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• pp.526-533
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• 2008

In this study, theoretical super screen vibration analysis has been carried out to predict the dynamic characteristics of interactive waste particles. In order to approach these problems, it is necessary to have a fundamental understanding the screening process and the process of both the remaining and the passed material on a screen with several interacting screen planes based on Soldinger(1999) was discussed. Here, the vibrating screen is composed of three assemblies such as screen, wastes guide, and supported screen as shown in Fig. 1. This model is regarded vibrator as the system of screen fixed tilt plates. Then materials(or particles) of different size is to be separated by using the eccentric vibrator and classifying tilt plates. As well moisturized construction wastes is more efficient to separate than moisture-less it. In processing separate mechanism, the more materials is light, the more staying time is long. Thus much lighter construction wastes(wood, Styrofoam, etc) and heavier materials are separated by staying time delay in a super screen. The design results, separation screen were able to know that small and larger particles are conspicuous difference each motion character according to trajectory particles, and small particles raise the probability in classifying tilt plates.

• 한국습지학회지
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• 제16권1호
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• pp.125-137
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• 2014

본 연구에서는 국내 기존 도달시간 산정방법에 있어 Kraven(II)는 경사구간별 3가지 유속을 제시하고 있으므로 해당 유역특성이 충분히 반영되지 못하고 있다. 이에 최근 "설계홍수량 산정요령, 2012. 국토해양부"에서 제안한 보완된 연속형 Kraven 경험식은 완경사부와 급경사부의 유속을 보완하였으며, 평균유속이 최소유속 1.6m/s에서 최대유속 4.5m/s의 범위내의 연속성의 유속을 나타내고 있어서 현실적으로 타당한 범위를 가지며, 도달시간도 매우 합리적인 결과를 나타내고 있으므로 기존의 불연속의 문제나 매우 완만한 경우와 급한 경우의 적용성에도 매우 우수한 것으로 나타나고 있다. 본 연구에서는 도달시간 산정방법에 있어 기존 Kraven(II) 경험식과 보완된 연속형 Kraven 경험식에 따른 수문곡선의 변화양상을 살펴보았으며, 동화천, 매호천, 욱수천, 금포천에 대해서 각 해당 유역특성을 고려하여 단위도법-도달시간 산정방법에 따른 홍수유출모의결과를 비교분석하였다.

• 한국산림과학회지
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• 제11권1호
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• pp.25-32
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• 1970

강원도산(江原道産) 적송림(赤松林)중 우량임분(優良林分)을 대상으로 해서 지위지수곡선(地位指數曲線)을 작성(作成)해 보았고 이에 대한 비평을 가했다. 시료관계(試料關係)로 기준연령(基準年令)을 25년(年)으로 잡았다. 작성방법(作成方法)으로서는 삼군분할법(三群分割法)을 적용했다. 다음에는 입목밀도(立木密度)를 검토(檢討)했는데 11개(個) plot의 입목도(立木度)는 기왕(旣往)의 수확표(收穫表)의 그것에 비해서 훌륭한 상태(狀態)에 있었다. 미국의 라이넥캐의 표준밀도에 비교한 이곳 적송임분(赤松林分)의 흉고직경(胸高直徑)대 단위면적(單位面積)당의 입목임수관계(立木林藪關係)를 제공했다. 이것을 보면 강원도적송림(江原道赤松林)의 밀도(密度)는 대단히 우량(優良)한 것으로 결론(結論)된다. 점밀도(點密度)로서 재적추정(材積推定)을 한다는 것은 신뢰성(信賴性)이 낮은 것이라는 토의(討議)를 가했고 조림학적(造林學的)인 또는 생태학적(生態學的)인 주요성으로 점밀도(點密度)의 개념을 선명했고 3가지 가설집단에 대해서 그 내용(內容)의 일단(一端)을 분석(分析)했다.

• 한국지반공학회논문집
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• 제20권1호
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• pp.131-139
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• 2004

지내력기초 설계와 시공을 위해 실시하는 평판재하시험 결과로부터 실제 기초지반의 지지력 및 침하량을 산정할때 scale effect를 고려해야 하는데 국내에는 scale effect 적용기준이나 관련 시험자료가 없다. 그래서, 화강풍화토 지반에서 재하판 크기별 지지력 및 침하량의 상관관계를 파악하기 위해 모형토조 및 현장 평판재하시험을 실시하였다. 토조시험은 토조내에 지층을 형성한후 함수비 조건, 다짐횟수, 습윤 단위중량, 및 재하판 직경(D15, 25cm)별로 모형토조$(2,000\times 2,000\times 1,000mm)$에서 실시하였다. 현장 재하시험은 재하판 직경$(D15, 25, 30, 40, 75\times 75, 140\times 210cm)$별로 실시하였다. 재하시험 결과분석과 수치해석을 통해 토사 및 암반지반에서 지내력 기초설계시 Scale effect를 계산하기 위한 지지력 및 침하량 산정식을 제시하였다.

• 한국IT서비스학회지
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• 제18권4호
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• pp.67-82
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• 2019

The purpose of this study is to improve the calculation method of the software operation pricing proposed by the software business price calculation guide from 'input manpower method' to 'rate calculation method'. The software operation pricing of the input manpower method is not objectively calculated in the domestic IT outsourcing situation where the statistical data based on the activity based estimating is insufficient and it is decided by agreement between the owner and the client. In addition, there was no standard for adjusting the productivity according to the characteristics of the operation service. In order to improve this, an operational correction factor item that can affect the software operation productivity was selected based on foreign and domestic standards, and it was confirmed through the first questionnaire to IT operation managers. In order to determine the level of difficulty of the fixed operational correction factors, the operational correction factor using AHP technique was confirmed through a second questionnaire for pairwise comparison. The operational difficulty calculation table was developed with reference to COCOMO and ITIL standards. Finally, we propose a new pricing scheme that reflects the operating rate. Regression analysis was carried out by collecting the data of the domestic public institutions on the estimated cost and the actual cost calculated from the new rate method software operation pricing. The results of the regression analysis show that the estimated cost and the actual cost are related to each other. Mean magnitude of relative error(MMRE) and PRED[25] analysis were added for accuracy analysis. MMRE and PRED also showed satisfactory results, confirming the possibility of replacing the rate method software operation pricing.

• 한국수정란이식학회지
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• 제11권2호
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• pp.103-109
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• 1996

The aim of this study was to evaluate the effect of recombinant bovine somatotropin (bST; Boostin-S, LG Chem) treatment with FSH (Super OV) or PMSG on superovulatory response for transvaginal ultrasound-guided oocyte retrieval (TVR) in calves. Eight Korean Native Cattle(KNC) heifer calves; 150 to 240 days old; were randomly assigned to four treatment groups: 1) FSH(75 mg); 2) FSH (75 mg) + bST(500mg) 3) PMSG(1;000 IU); 4) PMSG(1, 000 IU) + bST(500 mg). Experimental calves in group 1 (n=2) and 2(n=2) were weekly superovulated for 4 consecutive weeks with daily injection of FSH for 3days and the next day subjected to TVR session. Animals in group 3 (n=2) and 4(n=2) were weekly stimulated for 4 consecutive weeks with a single dose of 1, 000 IU PMSG. TVR was performed on 72 hours after PMSG injection. Calves in group 2 and 4 was received injection of 500 mg of bST every 10 days. At each TVR session, follicle number and size were recorded; the oocytes collected and graded according to cumulus and cytoplasm investment. Collected oocyte were determined viable oocyte according to morphological quality with granulation of oocyte and number and status of cumlulus cells. IVM and IVF were performed and assessed cleavage rate on day 3 after fertilization. A Sonovet 600(Medison, Co., Ltd) realtime ultrasound scanner with a 6.5 MHz convex transducer, fixed at the tip of 500 mm estended handle equipped with a needle guide was used in collecting oocyte. Differences between groups were analysed by chi-square test. The population of large follicle ($\geq$5 nun) and aspiration rate were not significant different among the 4 groups. But, the number of small follicles (<5 mm) and aspirated oocyte in the KNC calves treated with bST were 1.3~1.6 times higher than in KNC calves treat with FSH or PMSG alone. In conclusion, the administration of bST with FSH or PMSG at superovulation for TVR in calves was increase the nurnber of small follicle which was influenced the number of aspiratable follicle.

• 대한방사선치료학회지
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• 제10권1호
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• pp.69-77
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• 1998

When a high energy photon beam is used to treat lesions located in the upper respiratory air passages or in maxillary sinus, the beams often must traverse an air cavity before it reaches the lesion. Because of this traversal of air, it is not clear that the surface layers of the lesion forming the air-tumor tissue interface will be in a state of near electronic equilibrium; if they are not, underdosing of these layers could result. Although dose corrections at large distances beyond an air cavity are accountable by attenuation differences, perturbations at air-tissue interfaces are complex to measure or calculate. This problem has been investigated for 4MV and 10MV X-ray beams which are becoming widely available for radiotherapy with linear accelerator. Markus chamber was used for measurement with variouse air cavity geometries in X-ray beams. Underdosing effects occur at both the distal and proximal air cavity interface. The magnitude depended on geometry, energy, field sizes and distance from the air-tissue interfaces. As the cavity thickness increased, the central axis dose at the distal interface decreased. Increasing field size remedied the underdosing, as did the introduction of lateral walls. Fellowing a $20{\times}2{\times}2\;cm^3$\;air\;cavity,\;4{\times}4\;cm\;field\;there\;was\;an\;11.5\%\;and\;13\%\;underdose\;at\;the\;distal\;interface,\;while\;a\;20{\times}20{\times}2\;cm^3\;air\;cavity\;yielded\;a\;24\%\;and\;29\%$ loss for the 4MV and 10MV beams, respectively. The losses were slightly larger for the 10MV beams. The measurements reported here can be used to guide the development of new calculation models under non-equilibrium conditions. This situation is of clinical concern when lesions such as larynx and maxillary carcinoma beyond air cavities are irradiated.

• 융합신호처리학회논문지
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• 제20권3호
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• pp.118-124
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• 2019

최근 산업현장에서는 생산성, 품질, 고객 만족도를 향상시키기 위해 정보통신기술(ICT)을 기반으로 한 스마트 팩토리 체제로 전환하고 있다. 스마트 팩토리를 실현함에 있어 가장 중요한 장치는 무인 반송차(AGV)이며, AGV의 도입이 증가하고 있다. 일반적으로 AGV은 범용 PLC를 이용하여 개발하고 있으나, 범용 PLC로 개발된 AGV의 가격은 고가이며, 부피 또한 크다. 한편, 산업현장에서는 작업장의 공간적 제약 때문에 소형화, 용이한 재구성 등이 가능한 저가의 AGV를 요구하고 있다. 따라서 본 연구에서는 이러한 문제점을 해결하기 위해 PLC 내장형 AGV 제어기의 설계법을 제안하고, 그 성능을 평가하였다. 그 결과, 우수한 속도제어와 주행 정밀도(속도제어 오차=0.021[m/s], 주행자세제어의 평균오차 = 2.1[mm])를 보였다. 이와 같이 제안된 AGV 제어기를 산업현장에 적용한다면, 저비용으로 소형화와 재구성 등이 가능할 것이다.