• Journal of the Korean Solar Energy Society
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• v.25 no.2
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• pp.19-26
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• 2005

Concentric evacuated tube solar energy collector has been interested recently since government has driven to install alternative energy systems in new large building. In this paper, testing of the evacuated tube collector is conducted in outdoor during daytime by transient method. The collector thermal efficiencies are plotted in term of $(T_{in}-T_a)/Ic$, where $T_{in}$ is inlet working fluid temperature, $T_a$ is atmospheric temperature and $I_c$ is solar irradiation on the collector surface. The evacuated tube collector efficiency is ranged from 50% to 63% in real outdoor condition. In addition, the total overall heat loss coefficient is found to have an inverse variation to $(T_{in}-T_a)/I_c$ so that the coefficient becomes very high when $(T_{in}-T_a)/I_c$ is small.

• Fire Science and Engineering
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• v.24 no.5
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• pp.60-67
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• 2010

Fire model shall be verified and validated to reliably predict the consequences of fires within its limitations. Generally the verification and validation procedures are conducted by comparison with experimental test data. This study aims to evaluate predictive capabilities of FDS in the pool fire with two rooms and the sensitivity between input parameters such as heat release rate and ventilation rate and the output values like temperature, concentration, and heat flux. The predictive capabilities of FDS will be evaluated by comparing FDS simulation results with PRISME experimental data which result from the international fire test project. The sensitivity analysis will be conducted to decide which one of input parameters affects outcomes by comparison of FDS results with ${\pm}$ 10% changes of input parameter. From this study, the FDS predictive capabilities are within 20% error range. Heat release rate as input parameter affects most of outcomes and flow rate only has relation with concentration of oxygen and combustion products.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.6
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• pp.107-118
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• 2019

The purpose of this study is to analyze the effect of "emotional leadership" on innovative behavior and psychological depression through mediation of job engagement and self-efficacy. In order to accomplish this objective, hypotheses were set up and we distributed questionnaires to bankers and analyzed the final 294 copies. For the hypothesis test, the SPSS Process Macro was used for regression analysis and double mediation. As a result, emotional leadership positively affects self-efficacy, and self-efficacy positively affects job engagement and innovation behavior. Also, job engagement has a negative effect on psychological depression. As a result of verifying the dual mediation effect, both self-efficacy and job engagement showed a full mediating effect.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.275-281
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• 2013

Probiotics have been reported to benefit human health by modulating immunity, lowering cholesterol, improving lactose tolerance, and preventing some cancer. Once ingested, probiotic microorganisms have to survive harsh conditions such as low pH, protease-rich condition, and bile salts during their passage through the gastro-intestinal (GI) tract colonize and proliferate to exert their probiotic effects. The dual coating technology, by which the bacteria are doubly coated with peptides and polysaccharides in consecutive order, was developed to protect the ingested bacteria from the harsh conditions. The aim of the study was to evaluate the viable stability of a doubly coated blend of four species of Bifidobacterium by comparing its bile/acid resistance and heat viability in vitro with that of the non-coated blend. After challenges with acid, bile salts, heat, and viable cell counts (VVCs) of the dual coated and non-coated blend were determined by cultivation on agar plates or flow cytometric measurement after being stain with the BacLigtht kit$^{TM}$. The results showed that the dual coated blend was much higher resistant to the acidic or bile salt condition than the non-coated blend and heat viability was also higher, indicating that the dual coating can improve the survival of probiotic bacteria during their transit through the GI tract after consumption.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.324-331
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• 2013

All evacuated tube collector is being constantly studied since it can reduce the conductive heat loss in absorber by using vacuum technology and has advantage of heat transport capacity and quick thermal response in comparatively small temperature difference. This study investigated the dynamic thermal performance of the solar collector with the control condition of solar irradiance and fluid temperature by using performance experimental apparatus which is combined with solar collector and refrigerator, examined the thermal characteristics in definite temperature range of fluid in constant temperature tank by simultaneously measuring refrigerating performance. As a result of it, I deducted the related equation of collector efficiency and found that mean collector efficiency has increased through quick heat transfer characteristics according to increase of outdoor temperature and irradiance in case of outlet temperature of constant temperature tank $22^{\circ}C$ when set outlet temperature of solar collector $25^{\circ}C$ with outlet temperature of constant temperature tank $18^{\circ}C$ & $22^{\circ}C$. Also COP of refrigerator was acquired value of 6.2~7.1 at outlet temperature of constant temperature tank $18^{\circ}C$.

• Journal of Venture Innovation
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• v.3 no.2
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• pp.129-145
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• 2020

The purpose of this study was to examine the effects of the job characteristics of the PR practitioner on flourishing and to identify the mediating effect of the meaning of work and job engagement. This study used a survey of 353 PR practitioners from PR firms and the hypothesis was verified by gathering the data of the job characteristics, the meaning of work, the job engagement and the flourishing by conducting hierarchical regression analysis and SPSS Process Macro bootstrapping analysis. The results showed that the job characteristics of the PR practitioner were found to influence the flourishing with the double-mediation effect, the meaning of the work and job engagement. The more PR practitioners regard their work affects their surroundings, the higher the degree of autonomy is, and the more they get feedbacks they engaged more, as they valued their job more thereby experience flourish more. Moreover, when PR practitioners valued their job more, they more engaged in their work and experience flourish. The meaning of work revealed to be the important factor to affect flourish regardless of the job characteristics and the job engagement so that gained the results that PR firms' effort to elevate the meaning of work of PR practitioners has is important. The study findings suggest that PR practitioners' flourishing is manageable in the organization by paying attention to oneself in the aspect of the organization, not leaving in individual areas. Limitaions and implications for future studies were discussed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.981-984
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• 2011

A high-resolution numerical study is carried out to investigate the transient process of the combustion and the shock-train developments in an ethylene-fueled direct-connect dual-mode scramjet combustor. Following the fuel injection, air-throttling is applied at the expansion part of the combustor to provide mass addition to block the flow to subsonic speed. The ignition occurs several ms later when the fuel and air are mixed sufficiently. The pressure build up by the combustion leads to the shock train formation in the isolator section that advances to the exit of the intake nozzle. Then, the air-throttling is deactivated and the exhaust process begins and the situation before the air-throttling is restored. Present simulation shows the detailed processes in the dual-mode scramjet combustor for better understanding of the operation regimes and characteristics.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.208-213
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• 1998

Silicidation of the Co/Ti/Si bilayer system in which Ti is used as epitaxy promoter for $CoSi_2$has recently received much attention. The Co/Ti bilayer on the spacer oxide of gate electrode must be thermally stable at high temperatures for a salicide transistor to be fabricated successfully. In the $SiO_2$substrate was rapid-thermal annealed. The Sheet resistances of the Co/Ti bilayer increased substantially after annealing at $600^{\circ}C$, which is due to the agglomeration of the Co layer to reduce the interface energy between the Co layer and the $SiO_2$substrate. In the bilayer system insulating Ti oxide stoichiometric Ti oxide and silicide were not found after annealing.

• 전기의세계
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• v.15 no.2
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• pp.8-14
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• 1966

보편적으로 들수 있는 상용에너지 공급원으로는 신탄, 석탄, 석유, 천연가스, 수력을 들 수 있고 최근에는 핵분열(Nuclear Fission)을 이용한 원자력이 장래 에너지 공급원으로 가장 유망시되고 있다. 이 밖에 아직 상용으로 각광을 받지 못하고 있지만 금후 개발잠재력(Development Potential)을 갖고 있는 조력, 풍력, 태양열, 지열등이 있다. 이중 풍력은 주로 농사용 양수동력에 조력, 태양열, 지열은 발전용으로 상당히 이용되고 있는 지감도 있다. 본 고에서는 일차에너지인 수력, 석탄, 석유 천연가스 핵자원등에 대하여 살펴보기로 한다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.80.1-80.1
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• 2007