• Journal of Digital Convergence
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• v.17 no.2
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• pp.31-36
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• 2019

New technologies are being created and resulted as new types of fusion complex as the barrier between technology and industries are being broken and convergence is becoming more activated in the global economy of the era of fourth industrial revolution. Korea government is trying to foster innovative technologies for new technologies and new services to prepare for the fourth industrial revolution and gain global competitiveness, but many regulations make it difficult to verify and commercialize them. In response, the Korea government is pushing for the introduction of a regulation-free special zone system in which sandboxes are applied so that new technology and new service-based innovation projects can be freely commercialized through experiment and demonstration. This study aims to examine the limitations of the special zones for regional specialization development applied to the zones that are applied uniformly throughout the country and suggest ways for the deregulation special zone to be fostered as an empirical test bed based on new technologies and as a base for regional innovation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.4
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• pp.290-296
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• 2018

In this study, the cold test and the numerical analysis were carried out according to the shape parameters of the test model in order to confirm the operation range of high altitude environment simulation test facility for the supersonic vehicle. The blockage ratio, angle and length ratio were considered as the design parameters. The blockage rate is expected to be limited in the region of more than 40% due to the normal shock and expansion fan. It was confirmed that the angle of model should be selected at the size of 45 degrees or less due to the influence of the strong shock wave. There was no difference in performance between the lengths of 8 times the model diameter. Finally, we obtained the performance database according to the shape parameters of the conical test model and confirmed the operable range of the semi-freejet type high altitude environment simulation test facility.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.3
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• pp.91-100
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• 1988

Assuming that tidal level is constantly changed with an amplitude of 10 meters and a cycle of 12 hours, the slope stability for a typical dyke is analysed. The variation of pore water pressure within the dyke during the tidal change is obtained using a computer program, FLUMP, which is incorporated with saturated-unsaturated and transient flow. The results show that the variation of free water surface and distribution of pore water pressure within the dyke during the tidal fluctuations can be clearly predicted with the computer program. When a tide is lowered to the minimum level, the predicted pressure head is higher than the level of the free water surface in some parts of the dyke; that is, excess pore water pressure is generated in a zone affected by the tidal change. Also an unsaturated zone which shows negative pore water pressure is temporally created when a tide is lowered. The shear strength of the zone can be predicted based on the proposal suggested by Fredlund et al. It is emphasized that the excess pore water pressure generated during tidal fluctuations and strength parameters for the unsaturated zone should be considered in analyzing the slope stability of dykes. When those are considered, the critical slip surface seems to be located below the free water surface obtained when a tide is at the lowest.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.4
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• pp.369-383
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• 1993

An amended form of radiation stress is presented in the present model and the existence of the surface advection terms is verified through comparisons with wave energy equation. The model yields circulation patterns in both cross-shore and longshore directions on the plane beach slope. Comparison with laboratory experiments showed good agreements. Finally, a quasi-three dimensional model suitable for the entire nearshore zone is developed by linking the depth-integrated properties with vertical profiles.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.170-177
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• 2004

A single degree of freedom system and transmissibility are key concepts in many problems of vibration isolation. In order to apply this approach, however, several assumptions must be satisfied, which are often not realistic. In this paper, an approach using vibration power flow is introduced to deal with vibration isolations in a more practical way. Procedures of this approach and some results of research are presented. Difficulties in this method are also discussed.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.21-24
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• 2011

본 연구는 기업규모, 장부가치/시장가치 비율, 순이익/주가 비율, 현금흐름/주가 비율, 레버리지 등 기본적 변수를 사용하여 주식수익률에 유의적인 변수를 확인하고자 하였다. 이를 위해 본 연구에서는 횡단면 자료와 시계열 자료를 결합한 패널자료(panel data)를 이용하여 패널자료분석방법으로 연구모형을 실증적으로 분석하였다. 일반적으로 패널자료를 사용하면 Hsiao(2003)가 지적한 바와 같이 표본의 크기를 확대시켜 자유도를 증가시키고 이론적으로 설명변수간 다중공선성(muti-collinearity) 문제를 완화할 수 있다. 실증분석결과에 의하면 기업규모(SIZ), 장부가치/시장가치 비율(B/M), 순이익/주가 비율(E/P), 현금흐름/주가 비율(C/P) 등이 주식수익률의 횡단면적 차이를 설명할 수 있는 유의적인 변수라 할 수 있다.

• Journal of Korea Port Economic Association
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• v.25 no.1
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• pp.87-106
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• 2009

This paper is intended to suggest benchmarking ascension for the Gwangyang Port as a hub for international logistics. Most countries that seek to join. and lead, the global trading system as they work to develop production and logistics systems that establish a reputation for leadership in international logistics. Our focus in this research is on the Gwangyang Port and whether Gwangyang Port is capable of carving out a competitive niche as a hub of international logistics. Our analysis is based on comparison and analysis with benchmark port developments around the world. As proposals to promote and activate Gwangyang Port as a hub for international logistics, we recommended in this paper several benchmarks. First, Gwangyang Port FTZ must strengthen the incentive system for tenant companies and providing an inducement for new global companies. Second, Gwangyang Port needs to moderation of regulation on the investment tenant companies and strengthening one-stop service. Third, it is required to stabilize labor and management relationship and securing of flexibility of labor market. Lastly, Gwangyang Port must strengthen mutual interaction of Free Economic Zone (FEZ), Customs Free Zone(CFZ) and Free trade Zone(FTZ) in Korea.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.6
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• pp.467-473
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• 2007

Flow visualization study to qualitatively define the flow field over a stealth UCAV(Uninhabited Combat Air Vehicle) configuration in a water tunnel has been conducted to clarify the basic aerodynamic performance. The test was performed at freestream velocity of 12.7 cm/sec which was corresponding to a Reynolds number of $1.4{\times}10^4$ based on mean aerodynamic chord. The development and breakdown of vortices illuminated by using dye were compared to the previous force and moment data. It was shown that the effect of the vortices generated by the main-body and junction are dominant in the low angle-of-attack region. However, in the high angle-of-attack region, the vortex generated by the fore-body mainly influenced the aerodynamic performance of the model.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.307-312
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• 2020

Fluidized bed reactors operated in subatmospheric pressure has been focused because several industrial applications such as vacuum drying and plasma cvd requires reduced pressure fludization. However, the hydrodynamics of fluidized beds in subatmospheric pressure has not been extensively investigated. The pressure drop in the fluidized bed has been measured with variation of downstream pressures from 1.33 to 101.3 kPa in the shallow and deep fluidized beds under the sub-atmospheric pressures. The obtained minimum fluidization velocity of powders is a function of pressure due to the changes of gas density and mean free path. We can experimentally determine the critical Knudsen number and the critical pressure to define the slip regime significantly to influence the hydrodynamics of fluidized beds.

• Korea Petroleum Association Journal
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• no.2 s.96
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• pp.98-104
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• 1989

일본의 휘발유산출량할당제(P.Q제)가 오는 4월부터 폐지됨에 따라 일본석유업계는 본격적인 자유경쟁시대에 들어선다. 그동안의 업계보호정책으로 인해 체질개선이 늦어진 석유업계인 만큼, 이제 적자생존의 시장경쟁원리가 도입되면 정제 및 원매사는 물론 특약점이나 일선 주유소까지도 치열한 판매경쟁에 휩쓸리게 될 전망이다. 더우기 PQ폐지로 말미암아 업계재편바람이 불 것이라는 예상도 있다. 우리는 타산지석의 감으로, 일본석유업계의 규제완화흐름을 주시하지 않을 수 없으므로 현지언론의 예측을 중심으로 현상과 문제점을 살펴본다. <편집자 주>