• The KSFM Journal of Fluid Machinery
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• v.16 no.1
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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.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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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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• v.22 no.1
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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.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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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.

• Journal of the Korean Society for Library and Information Science
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• v.14
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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.

• Journal of The Korea Institute of Healthcare Architecture
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• v.16 no.2
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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.

• Journal of Embryo Transfer
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• v.23 no.3
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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.

• Journal of Embryo Transfer
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• v.26 no.3
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• pp.195-199
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• 2011

The objective of this study was to evaluate the efficiency of the conventional slow freezing and vitrification methods for cryopreserving in vivo and in vitro-produced bovine embryos. Morphology of post-thawed embryos was evaluated and normal embryos were used for successive culture for 72 h. In experiment I, In embryo viability, There was no significant differences in blastocyst re-expansion rates were found between in vivo and in vitro embryos(89.6% vs. 81.5%). whereas hatched-BL and total cell number rates was significantly higher (p<0.05) for in vivo-derived embryos (76.9%, 136${\pm}$3.6 vs. 43.4%, 107${\pm}$3.8). In experiment II, There was no significant differences in blastocyst re-expansion and Expansion-BL rates were found between in slow freezing and vitrification methods (91.3% vs. 85.7% and 71.4% vs. 75.0%, respectively). in conclusion, These results suggested that the field application for bovine embryo transfer is in part supported by improvements of technologies in embryo conventional slow freezing and vitrification cryopreservation.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.92-100
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• 2015

This study proposes measures to improve management performance of construction projects by re-designing the organizational structures of the Regional Construction Management Administrations of the Ministry of Land, Infrastructure and Transport. The re-designing measures are derived based on the three measures which were established by analyses on status of the Regional Construction Management Administrations, requirements from the current organizational structure, and domestic/overseas examples; the measures are: 1) organizational integration and scope expansion, 2) structural re-organization according to construction projects, and 3) building a knowledge management structure. In order to realize the re-designing measures, sixteen tasks are derived; a milestone is established according to importance, feasibility and lead-lag relationships of these tasks. If these tasks are to be carried out successfully, the management performance of the Regional Construction Management Administrations of the Ministry of Land, Infrastructure and Transport will be expected to improve. Ultimately, the Regional Construction Management Administrations can reduce cost and improve the quality of public service by outsourcing the non-core competence tasks and by concentrating on the construction management for the new infrastructure projects.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.6
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• pp.81-93
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• 2016

An actual analysis was made regarding how different the effect of the online WOM information characteristics on the expansion of the WOM information characteristics was depending on the level of the receiver's expertise in consideration of the sender's expertise, the vividness and Consensus of WOM information which can affect the acceptance of WOM information in this study. To begin with, the analysis results showed that the online WOM information characteristics had the positive effect on the information acceptance intention in proportion to the sender's expertise and the vividness and Consensus of WOM information. Secondly, the information acceptance intention was found to have a positive effect on the re-WOM intention. Finally, the level of receiver's expertise was found to control the effect of the online WOM information characteristics on the information acceptance intention.