• Proceedings of the SAREK Conference
• /
• 2005.11a
• /
• pp.317-322
• /
• 2005

This study is aimed to analyze the effects of heat pipe shape on the heat transfer in solar collector with a axial grooved heat pipe. In the design of a heat pipe. two of the most important criteria to be met are the operating temperature range and the maximum heat transport capacity, When the operating temperature range is known and the working fluid has been selected, the maximum heat transport capacity depends strongly on capillary pressure and liquid flow. The heat transport capacity of the heat pipe will depend on the geometry of the heat pipe, the wick structure. the vapor channel shape. groove number. cooling temperature. condenser length and pipe diameter. So various shapes are used for mathematical models of two-phase flow in grooved heat pipe. From the results. the adequate groove shape and scale are presented by considering the heat transport and capillary limitation.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.16 no.3
• /
• pp.50-57
• /
• 2008

This paper analyse the economic inducement effects of aviation industry using Input-Output Model. For measuring economic inducement effects of aviation industry on korean economy, this paper divides air transport industry as two - manufacturing industry and service industry. we also use Input-Output Table of year 1990 through 2003 from Bank of Korea. Empirical results tells that aviation manufacturing industry have high product inducement effects to national economy although its low value-added coefficient such as 0.486 for aviation manufacturing industry and 0.447 for aviation service industry. public R&D doesn't have much effect to each of aviation industries.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.15 no.4
• /
• pp.108-116
• /
• 2007

The purpose of this study is to analyze the technical and cost efficiency of Air Transport Industry on Global strategic alliances. In particular, this study develops Stochastic Frontier Approach for accurate judgement. Based on 20 major international airline corporations related with strategic alliances during the period 1995-2001, we find that alliances make a significant contribution to efficiency. On the other hand, it is found that the level of contribution to efficiency is different according to alliances. These results also changed greatly between pre- and post- Asian financial crisis period.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.23 no.2
• /
• pp.84-88
• /
• 2015

In this study, we surveyed the CAO Dangerous Goods, the Cargo Compartment Classification, IATA DGR(Dangerous Goods Regulations), ICAO Doc. 9284 and the regulation for the Air Transport of Dangerous Goods by Ministry of land Infrastructure and Transport of Korea. We found that the differences between these regulations. Applied according to the type of dangerous goods cargo compartment Class is determined. These regulations have caused confusion was due to the difference, because of the need for revision and amendment regulations were analyzed.

• Journal of Korean Society for Atmospheric Environment
• /
• v.8 no.3
• /
• pp.162-168
• /
• 1992

Numerical solutions to the advection equations used for long-range transport air pollution models are calculated using three numerical methods; Antidiffusion correction method(Smolarkiewicz, 1983), Positive definite advecton scheme obtained by nonlinear renormalization of the advective fluxes(Bott, 1989), and Positive definite pseudospectral method(Bartnicki, 1989). Accuracy, numerical diffusion and computational time requirement are compared for two-dimensional transport calculations in a uniform rotational flow field. The solutions from three methods are positive definite. Bartnicki(1989)'s method is most conservative but requires approximately 10 times as much computational time as Smolarkiewicz(1983)'s method of which numerical diffusion is the largest. All three methods are more conservative for a cone shape initial condition than for a rectangular block initial condition with a steep gradient.

• Journal of Advanced Navigation Technology
• /
• v.4 no.1
• /
• pp.78-92
• /
• 2000

This study will be regarded significant in terms that empirical analysis was used to prove "Aviation Safety", a variable which had not been regarded as a airline choice factor within Korea air transport market so far, has an effect on the aviation consumers' airline preference change and choice after recent frequent aviation accidents. On releasing this paper. I wish, it can be another opportunity for Korean two national flag airlines to reappraise and reinforce the significance of "aviation safety" and set forth immediate vigorous efforts to support the government's aviation safety improvement countermeasures The study was performed to provide data and information for this.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.10 no.2
• /
• pp.180-192
• /
• 1998

Enthalpy transport in a pulse tube was investigated by two-dimensional analysis of mass, momentum and energy equations assuming that the axial temperature gradient in the pulse tube is constant. Time-averaged second-order conservation equations of mass, momentum and energy were used to show the existence of steady mass streaming and enthalpy streaming. Effects of axial temperature gradient, velocity amplitude ratio and heat transfer between the gas and the wall on the steady mass streaming and enthalpy streaming were shown. Enthalpy loss due to the steady mass streaming is zero for basic and orifice pulse tube refrigerators, but it is proportional to the axial temperature gradient and steady mass flow rate through a pulse tube for double inlet pulse tube refrigerators.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.7
• /
• pp.33-44
• /
• 1999

Enthalpy transport in a pulse tube was investigated by two-dimensional analysis of mass, momentum and energy equations assuming that the axial temperature gradient in the pulse tube was constant. The time-averaged second-order conservation equations of mass, momentum and energy were used to show the existence of steady mass and enthalpy streaming. Effects of the axial temperature gradient, velocity amplitude ratio, and heat transfer between the gas and the tube wall On the steady mass and enthalpy streaming were shown. Enthalpy loss due to the steady mass streaming is zero for basic and orifice pulse tube refrigerators, but it is proportional to the axial temperature gradient and steady mass flow rate through a pulse tube for double inlet pulse tube refrigerators.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.2
• /
• pp.113-132
• /
• 2003

In May 2001, the Stockholm Convention on Persistent Organic Pollutants (POPs) for phasing out and eliminating POPs was signed by 90 countries at the Diplomatic Meeting in Stockholm. In 1998, three years before the Convention, the protocols on POPs and heavy metals were adopted by the United Nations Economic Commission for Europe under the Convention on Long-Range Transboundary Air Pollution. Growing attention on POPs and heavy metals during the past 10 years is primarily due to their toxicity in minute quantities. POPs and some metal compounds are even more toxic because of their bioaccumulation potentials associated with a high lipid solubility. Furthermore, owing to their persistence and semi - volatility, they are widely distributed in the environment, traveling great distances on wind and water currents. Recent international cooperation to address POPs and heavy metals has focused on these issues. Long -range transport of those pollutants are particularly concerned since Korea is located downwind of prevailing westerlies from China. In this paper, a review is provided to assess the properties, sources, emissions, and atmospheric concentrations on POPs and heavy metals.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.277-281
• /
• 2008

This paper presents the development of a high efficiency transport refrigeration system for sliced-raw fish transportation. The refrigeration system is equipped with heat storage for reverse cycle-hot gas defrost (the stored heat is used during defrost cycle of the system). System performance and container operating conditions are analyzed during experimental investigation on a $3,225{\times}1,740{\times}1,640\;mm$ full-scale refrigerated container under cooling and defrosting conditions. The prototype system indicates better performance in terms of shorter cooling-down time, shorter defrost time and smaller fluctuations of refrigerated container's temperature.