• 정보관리연구
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• 제39권3호
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• pp.49-71
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• 2008

이 연구는 국내 의학도서관 정보이용교육의 활성화를 도모하고, 아울러 정보환경의 변화에 부응하고 이용자 지향적인 정보이용교육 프로그램을 제시하기 위하여 수행되었다. 이를 위해 국내외 선진 사례들을 벤치마킹한 뒤, 국내 평균에 가까운 한 대학도서관을 주요 사례로 하여 정보이용교육의 실태와 이용자들의 정보요구를 조사하였다. 이를 바탕으로 국내 의학도서관 정보이용교육의 프로그램 구성을 위한 방안을 제시하였다. 특히 프로그램을 구성할 때의 고려사항, 내용, 흐름을 제시하였다. 이 연구의 결과는 국내 의학도서관들이 정보이용교육 프로그램을 시작하거나 보완하고자 할 때 유용한 참조원이 될 것이다. 각 의학도서관은 자관의 상황에 따라 이 연구의 결과를 적절히 가감하여 활용할 수 있을 것이다.

• 한국식품과학회지
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• 제20권3호
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• pp.303-309
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• 1988

Extruder 조작조건에 따른 extruder 내부물질의 온도변화는 제품의 물리화학적인 특성에 큰 영향을 미치는 요소이다. 자가발열형 single screw extruder를 사용하여 원료의 종류, 입자크기 수분함량과 같은 사입원료 조건과 사출구의 형태, breaker의 형태등과 같은 extruder의 구조적인 요소 및 냉각방법과 스크류 회전속도와 같은 작동조건을 달리했을 때의 작동초기 단계에서 열발생 속도와 평형상태에서 내부온도 분포를 관찰하였다. 쌀가루, 보리가루, 밀가루, 탈지대두분을 원료로 하여 각각 압출성형했을 때 바렐내부 발열상태를 보면 탈지대두분이 가장 급격한 온도증가를 나타내었으며 쌀가루가 가장 낮게 나타났다. 수분함량이 감소함에 따라 각 부위 온도 및 동력요구량은 증가했고, 입자크기가 작을 수록 표면적이 증가하여 압축부위 온도가 높았다. 스크류 회전속도가 증가함에 따라 각 부위의 온도가 높아졌다. 또한 바렐내부 온도분포가 계량부위>사출구부위>압축 부위 순서로 이루어질 때 extruder 작동상태가 가장 양호하였다.

• 상하수도학회지
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• 제27권1호
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• pp.21-29
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• 2013

Present study was conducted to evaluate the performance of Anaerobic Hybrid Reactor (AHR) combined with two types of anaerobic attached growth reactors at mesophilic temperature ($37^{\circ}C$). The reactor was operated at the influent substrate condition of 19,400 mg/L soluble chemical oxygen demand (sCOD). The organic loading rate (OLR) and flow rate were varied in the range of $9.5{\sim}22.5kg/m^3$. day and 10.6 ~ 26.0 L/day respectively since start-up was done. The COD removal efficiency of 93 % was measured at the OLR of $14kg/m^3$. day in AHR. However a reduction in removal efficiency to as low as 85 % could have been related to a combined effect of high concentration suspended solids (SS) concentration over 3,800 mg/L. On the other hand the total COD removal efficiencies were measured to be 96.3 % and 96.2 % for AHR+APF and AHR+ADF respectively. The pH of the POME was adjusted to neutral range by using sodium bicarbonate at the initial stages of the reactor feed, later stages pH adjustment was not required as the pH was maintained in the desired neutral range due to self-buffering capacity of the reactor. The reactor proved to be economically acceptable and operationally stable. The biogas was measured to have $CH_4$ and $CO_2$ with a ratio of 35:65, and methane gas production rate was estimated to be $0.17{\sim}10.269L\;CH_4/g\;COD_{removed}$.

• 한국분무공학회지
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• 제25권1호
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• pp.8-14
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• 2020

Recently, 1-D model-based engine development using virtual engine system is getting more attention than experimental-based engine development due to the advantages in time and cost. Injection rate profile is the one of the main parameters that determine the start and end of combustion. Therefore, it is essential to set up a sophisticated model to accurately predict the injection rate as starting point of virtual engine system. In this research, procedure of 1-D model setup based on AMESim is introduced to predict the dynamic behavior and injection rate of diesel injector. As a first step, detailed 3D cross-sectional drawing of the injector was achieved, which can be done with help of precision measurement system. Then an approximate AMESim model was provided based on the 3D drawing, which is composed of three part such as solenoid part, control chamber part and needle and nozzle orifice part. However, validation results in terms of total injection quantity showed some errors over the acceptable level. Therefore, experimental work including needle movement visualization, solenoid part analysis and flow characteristics of injector part was performed together to provide more accuracy of 1-D model. Finally, 1-D model with the accuracy of less than 10% of error compared with experimental result in terms of injection quantity and injection rate shape under normal temperature and single injection condition was established. Further work considering fuel temperature and multiple injection will be performed.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2000년도 추계학술대회
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• pp.26-31
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• 2000

It is said that the focus of managing venture business is currently moving from technology competition to management competition. By the way, the software venture business(SVB) has some weak points in its structural composition and itematization and no professional personnel in other several sections except technology development section. In addition, such basic functions as technology and R & D, finance and accounting, marketing required to the management of business are concentrated on only one man, its representative director. Therefore, this study aims to provide the basic data useful to the establishment of governmental policy in information and communication, to the rearing of the SVB by a local government related to the software, and to the administration of SVB by investigating the actual conditions. This study attempts to examine the literature on venture business and software industry, and its management with a questionnaire about the actual conditions of managing the SVB. The questionnaire is given to 527 local enterprises belonging to the Software Industry Association and to 171 enterprises in the Software Center. This study compromises the characteristics of the SVB, the actual conditions of its technology and R & D, finance and accounting, and marketing. The characteristics of the SVB are classified into categories such as the stage of its growth(the stage of its seed and start-up, the stage of tis development and growth, the stage of its stability and maturity) and the main business(the system integration, the software development for contract, the package software development service, the software-related service). Additionally, the study attempts to analyze positively the actual condition of its management after classified by the areas of business profile, its general management, its technology development, its finance and accounting, and its marketing The result of this study is found that the SVB has a lot of troubles in part of marketing and finance & accounting activity as well as general management. The SVB realizes the importance of the technology development rather than that of management activity including marketing activity. So we expect this study can assist the SVB to establish the business guidelines for own management plans.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.305-309
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• 2007

FTL(Fuel Test Loop) is a facility that confirms performance of nuclear fuel at a similar irradiation condition with that of nuclear power plant. FTL construction work began on August, 2006 and ended on March, 2007. During Construction, ensuring the worker's safety was the top priority and installation of the FTL without hampering the integrity of the HANARO was the next one. The installation works were done successfully overcoming the difficulties such as on the limited space, on the radiation hazard inside the reactor pool, and finally on the shortening of the shut down period of the HANARO. The Commissioning of the FTL is to check the function and the performance of the equipment and the overall system as well. The FTL shall start operation with high burn up test fuels in early 2008 if the commissioning and licensing progress on schedule.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.125-130
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• 2008

The main components of the KSTAR helium refrigeration system (HRS) can be classified into the warm compression system (WCS) and the cryogenic devices according to the operating temperature levels. The WCS itself consists of the compressor station (C/S) and the oil removal system (ORS). The process helium is compressed from 1 bar to 22 bar maximum in the C/S and downstream, the ORS removes the oil mixed in the helium to less than 10 ppbw as per the operation criteria of the cryogenic devices of the KSTAR HRS. After the installation, the pre-commissioning and commissioning activities were started on July, 2007. Before the start-up of the C/S, vibration measurement and the skid reinforcement jobs were performed for stable operation of the C/S. The results of the WCS performance tests met the requirements of the KSTAR HRS but satisfied the vibration level criteria only at the compressors' full load condition.

• 플랜트 저널
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• 제12권4호
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• pp.37-43
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• 2016

원자력발전소의 사고 대처 부하에 전력을 공급하는 전원계통은 다양한 조건에서도 일정 전압이 유지됨을 분석을 통하여 입증한다. 이를 위하여 발전소를 일정부하 운전 상태로 유지하고, 대용량 전동기(원자로냉각재펌프(RCP), 기기냉각수펌프(CCWP))를 각각 기동하여 기동 전 후 안전관련 모선의 전압을 측정하였다. 현장 시험으로 확보된 자료(예, 전압, 전류, 역율 등)는 기존 전력계통해석 모델의 운전 조건으로 재입력하고 재분석을 수행하였다. 이는, 기존 전력계통분석에 사용된 분석기법과 가정들을 실질적인 측정과 결과 분석으로 입증하는 과정이다. 결국, 두 경우의 전압 강하는 발전소 안전에 중요한 기기의 전압이 허용전압 이하로 저하되지 않음과 두 값의 비교 결과가 요구되는 제한치 이내임을 검증한다.

• Nuclear Engineering and Technology
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• 제41권6호
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• pp.831-840
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• 2009

In order to evaluate the start-up behavior and to identify, through abnormal operation occurrences, the transient behaviors of the Sulfur Iodine(SI) process, which is a nuclear hydrogen process that is coupled to a Very High Temperature Gas Cooled Reactor (VHTR) through an Intermediate Heat Exchanger (IHX), a dynamic simulation of the process is necessary. Perturbation of the flow rate or temperature in the inlet streams may result in various transient states. An understanding of the dynamic behavior due to these factors is able to support the conceptual design of the secondary helium loop system associated with a hydrogen production plant. Based on the mass and energy balance sheets of an electrodialysis-embedded SI process equivalent to a 200 $MW_{th}$ VHTR and a considerable thermal pathway between the SI process and the VHTR system, a dynamic simulation of the SI process was carried out for a sulfuric acid decomposition process (Second Section) that is composed of a sulfuric acid vaporizer, a sulfuric acid decomposer, and a sulfur trioxide decomposer. The dynamic behaviors of these integrated reactors according to several anticipated scenarios are evaluated and the dominant and mild factors are observed. As for the results of the simulation, all the reactors in the sulfuric acid decomposition process approach a steady state at the same time. Temperature control of the inlet helium is strictly required rather than the flow rate control of the inlet helium to keep the steady state condition in the Second Section. On the other hand, it was revealed that the changes of the inlet helium operation conditions make a great impact on the performances of $SO_3$ and $H_2SO_4$ decomposers, but no effect on the performance of the $H_2SO_4$ vaporizer.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.520-523
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• 2016

본 논문에서는 MPPT(Maximum Power Point Tracking) 기능을 갖는 열에너지 하베스팅을 위한 DC-DC컨버터를 설계하였다. 설계된 회로는 열전소자로부터 수확된 낮은 전압을 변환하여 부하에 승압된 전압을 공급한다. 시동회로는 제어기가 동작할 수 있는 VDD를 공급하고 결과적으로 Main 부스트 변환기의 파워스위치를 ON/OFF하게 되며, 스위칭 동작을 통해 부하에 승압된 전압을 공급한다. Bulk-driven 비교기를 이용하여 낮은 전압에서도 비교동작을 가능하게 하였고, 이를 이용하여 시스템 효율을 높이고, 전압안정화 동작을 하게 된다. 최대 효율은 76%이다. 제안된 회로는 0.35um CMOS 공정으로 설계되었으며, 모의실험을 통하여 동작을 검증하였다. 설계된 회로의 칩 면적은 $933um{\times}769um$이다.