• 한국유체기계학회 논문집
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• 제16권1호
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• pp.17-23
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• 2013

Recently so much attention has been focused on renewable energy and, since its sources to exploit are already almost saturated in the country, the practical alternative to this situation could be a micro-turbine which uses the low head and low flow. From a point of view of local micro-turbine design capacity and manufacturing technology, the problems such as the accumulation of technical skills, the expansion of related industries, the national policy expansion and the turbine efficiency to improve are still vulnerable and it's true that there are also negative views about the economic feasibility, the technicity and the operation management of the micro-turbine. However, if the improvement can be done in technology of low-head double regulation micro-turbine to generate more outputs and the operation management can be reliably realized, the micro-turbine will be re-evaluated as an appliable source of renewable energy, even the output is small, and by a paradigm shift, it could realize a power generation as an economic and rational system.

• 한국군사과학기술학회지
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• 제9권3호
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• pp.77-87
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• 2006

Micro- or nano-size particles are required to improve the combustion efficiency and stability in the case of solid explosives and propellants. The micro-structural properties of an energetic material strongly influence the combustion and explosion behavior. However, the traditional size reduction techniques, including milling, are not suitable for production of ultra-fine size particles. As an alternative to the traditional techniques, various re-crystallization processes based on supercritical fluids have recently been proposed. Supercritical fluids are fluids at temperatures and pressures above their critical point. In principle, they do not give problems of solvent contamination as they are completely released from the solute when the decompression occurs. Rapid Expansion Supercritical Solutions(RESS) and Supercritical Anti-Solvent Process(GAS/SAS) are representatives of a nano-size particle formation process of energetic materials using supercritical fluids. In this work, various fine particle formation processes using supercritical fluids are discussed and the results are presented.

• Journal of Information Technology Applications and Management
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• 제22권1호
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• pp.61-76
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• 2015

In general universal service in telecommunications means a regulatory tool to secure the availability of basic communication services like fixed telephony at an affordable price throughout a country. A re-evaluation of the scope of existing universal service, however, is becoming a core issue as the penetration and usage of broadband and mobile communications matures and a new ICT ecosystem emerges. This study examined whether the universal service polices in Korea need adapting and updating to include broadband and mobile telephony in the universal service, which is based on the necessary and sufficient conditions derived from previous research and foreign countries' experiences : geographical ubiquity of a certain service and the market's ability to provide the service. The result shows the nationwide ubiquity of broadband and mobile communications exists but the ultimate goal pursued by universal service polices trying to make them available and affordable for all is being fulfilled by market dynamics in Korea. Thus, the inclusion of both services in the scope of universal service is regarded as an unnecessary regulation at present time and the expansion of universal service could be addressed as a long-term issue depending on market conditions in the future.

• 대한기계학회논문집
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• 제18권7호
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• pp.1759-1772
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• 1994

In this study, we re-examined the Tate's modified Bernoulli equation to study penetration phenomena for long rod projectile into single or multi-layered finite thickness plates. We used the force equlibrium equation at mushroomed nose/target interface instead of conventional pressure equation at the stagnation point. In our penetration model, we considered the velocity dependent $R_t$ value for semi-infinite target and considered only the back face effect for finite target. To compensate for $R_t$ value according to target's thickness and back face effect, we used the spherical cavity expansion theory for semi-infinite plate and used the cylindrical cavity expansion theory for finite plate. Also we developed the experimental technique using make screen to measure the penetration duration time at each layered plate. In 3-layered laminated RHA/mild steel/ A1 7039 plate, we observed that spall had occured around the back face of A1 7039 plate by the stress wave interaction. Through the comparison between theoretical and experimental data including Lambert's results, we conform that our study has good confidences.

• 한국문헌정보학회지
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• 제14권
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• pp.19-65
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• 1987

Library classification schedule IS based on the classification theory, principle and the system of the classification of science. It should be consisted of the basic principle of library classification which should use the library materials effectively. Continuous study and research on the each subject field of the discipline are essential for keeping up with the transformation of each learning field and the change of modern society. In this paper, I studied comparatively the sections and subsections of the management in KDC, DDC and NDC and reviewed the academic systems of each subject area in the management. I tried to compare the relationship beween the structure of library classifications and academic systems for the more specialized subsections of the management. KDC is influenced by the principle and structure of DDC, but I found that KDC is more similar to NDC than DDC in the sections and subsections of the management. Being un sufficient of subsections of KDC and NDC, they are not enough for the expansion and specialization of the subsections in the management. DDC is necessary to re-schedule for the proper expansion of 650 and 658 with reflection of the importance of that sections and academic systems. In this study, I adoped 9 sections of management, (1) Management policy (2) Administrative organization (3) Personnel (4) Office management and business information management (5) Marketing (6) Financial management (7) Production management (8) Accounting (9) International management. It would be necessary for us to study continuously about the specilized subsubsections of the management for the more professional classification.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제16권2호
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• pp.17-28
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• 2010

The considerable increase of the elderly with dementia is expected annually and when we think about the family members' and the patients' suffering, it could be painful. Above all things, it imposes heavy economic burdens on the family members that have patients who suffer from diseases of age like dementia or paralysis that caring them at home and also, it is not desirable for those old people in point of physical or environmental circumstances for medical care. Thus, it is needed urgently that the expansion of specified facilities and improvement of services for these old people. Under this present condition, it is the special feature that the subject of research is people/facilities that offer services, not the elderly with dementia-the main user of those facilities. This proposal aims to make a study of expansion and improvement the old people's welfare facilities by using remodeled closed Small and Midium Hospitals which are the bad effect of economic growth. Also, it can save money with re-using abolished buildings which is property of the nation and protect environment too. In this study, We examine the present conditions of old people's welfare institution, and research a factor of remodeling for welfare facilities. Then we will verify remodeling-possibility which is concrete and working by using the product of this study.

• 한국수정란이식학회지
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• 제23권3호
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• pp.223-227
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• 2008

The cryopreservation of Hanwoo embryos has become an integral part of assisted reproduction in animal. The objective of this study was to assess the effect of The objectives of this study were: (1) to evaluate the influence of bovine embryo developmental stage on in vitro embryo development after freezing, (2) to study the efficiency compared with conventional freezed embryos at different embryo source. For conventional slow-freezing, day 7 or 8 expanded blastocysts were collected. The standard freezing medium was 1.8 M ethylene glycol (EG). Embryos were equilibrated in 1.8 Methylene glycol(EG) with 0.1 M sucrose in Dulbecco's phosphate-buffered saline (D-PBS) supplemented with 0.5% bovine serum albumin. Embryos were then loaded individually into 0.25 ml-straw and placed directly into cooling chamber of programmable freezer precooled to $-7^{\circ}C$, after 2 min, the straw was seeded, maintained at $-7^{\circ}C$ for 8 min, and then cooled to $-35^{\circ}C$ at $0.3^{\circ}C$/min, plunged and stored in liquid nitrogen for at least 3 days. For thawing, the straw containing embryos were warmed in air for 10 see and exposed to $37^{\circ}C$ water for 20 sec. Straws were then removed from $37^{\circ}C$ water. Rates of blastocyst survive and hatched were evaluated at 12 to 48h post-warming. The re-expansion and hatched rates of morula embryos were significantly lower than those obtained for blastocysts and expansion blastocysts (31.6%, 10.5% vs, 68.9%, 22.2% vs, 73.7%, 53.6%, respectively). No differences in re-expansion rates were found between in vivo and in vitro blastocysts. whereas hatched rates was significantly higher (51.2%) in vivo compared with in vitro embryos (18.6%). in conclusion, demonstrate that conventional freezing can be used successfully in cryopreservation of in vitro and in vivo bovine embryos, and that it might be considered for use in commercial programs and embryo preservation.

• 한국수정란이식학회지
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• 제26권3호
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• pp.195-199
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• 2011

포유동물 수정란의 동결보존기술은 최근 기후 변화에 따른 생물종 다양성을 보존하기 위해서 중요하게 여겨지는 연구 분야이다. 따라서 멸실 위험에 처한 동물의 개량과 증식, 보존과 복원 및 생명공학의 분야에 이르기까지 응용 기술은 다양하게 이용되어진다. 본 연구에서는 한우 수정란의 동결 후 생존성 향상을 위해서 동결 방법에 따른 체내 외수정한의 내동성을 조사하였다. 완만동결에 따른 체내 외수정란의 동결 융해 후 수정란의 재확장률은 89.6%와 81.5% 그리고 72시간 배양하였을 때 부화된 수정란은 76.9%와 43.4%, 생존수정란의 총세포수는 136${\pm}$3.6개와 107${\pm}$3.8개의 결과를 보여 동결 융해 후 생존율에서는 차이를 보이지 않았으나, 수정란의 부화율과 세포수 조사에서는 체내수정란이 유의적으로(p<0.05) 높은 결과를 보였다. 체내수정란의 완만동결 후 배반포 회복률은 91.3% 그리고 12시간 이상 배양하였을 때 확장배반포까지의 발달률은 71.4%의 결과를 보였으며, 초자화 동경에서는 85.7%와 75.0%의 결과를 보였다. 결과적으로 본 연구에서 수행된 체내 외 수정란의 동결기술을 이용한다면 수정란이식 현장에서도 효과적인 활용이 가능할 것으로 사료된다.

• 한국건설관리학회논문집
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• 제16권1호
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• pp.92-100
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• 2015

본 연구에서는 국토교통부의 지방청 조직의 재설계를 통해 건설사업관리를 활성화하기 위한 방안을 제시하고 있다. 재설계 방안은 지방청 현황분석, 현업 요구사항 분석, 국 내외 선진사례분석을 통해 수립된 조직 통합 및 광역화, 사업관리 조직화, 지식관리 조직화라는 3대 개선방향을 바탕으로 도출되었다. 이후 조직 재설계방안을 구현하기 위해 16개의 추진과제를 도출하였으며, 이들 과제에 대한 중요도, 실현가능성 및 선 후행관계를 바탕으로 추진일정계획을 수립하였다. 수립된 추진일정계획을 바탕으로 도출된 추진과제를 성공적으로 수행한다면, 국토교통부 지방청 조직의 건설사업관리가 보다 활성화 될 수 있을 것이라 기대한다. 궁극적으로는 시설 운영 및 유지보수관리로 대변되는 비핵심역량 영역을 외부에 위탁하고, 지방청 역량을 신규 SOC 건설에 대한 사업관리에 집중함으로써 비용절감 및 대국민 서비스향상을 이룰 수 있을 것이라 기대한다.

• 한국산업정보학회논문지
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• 제21권6호
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• pp.81-93
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• 2016

본 연구는 구전정보 수용에 영향을 미칠 수 있는 발신자의 전문성, 구전정보의 생생함과 동의성을 고려하여 온라인 구전정보특성이 구전정보 확산에 미치는 영향관계가 수신자의 전문성 수준에 따라 어떻게 차이가 나는지 확인하고자 실증 분석하였다. 분석결과 첫째, 발신자의 전문성이 높고 구전정보가 생생하고 동의성이 높을수록 정보수용의도에 긍정적인 영향을 미치는 것으로 나타났다. 둘째, 정보수용의도가 재구전의도에 긍정적인 영향을 미치는 것으로 나타났다. 셋째, 수신자의 전문성 수준은 온라인 구전정보 특성이 정보수용의도에 미치는 영향력을 조절하는 것으로 나타났다.