• Journal of the Korean Solar Energy Society
• /
• v.27 no.3
• /
• pp.71-77
• /
• 2007

In past, parking lot was placed on the ground and for the reason air quality was not in problem. But recently parking lot has been placed under the ground and the air quality becomes problem. So in this study, the ventilation performance on the underground parking lot was estimated by using CFD software and alternative system was suggested. Three case studies are handled in this study. 1st case is just an underground parking lot. 2nd case is about an underground parking lot where has 4 fan rooms on each floor and 3rd case is about an underground parking lot where has 4 fan rooms and 30 guidance fans on each floor.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2017.11a
• /
• pp.148-150
• /
• 2017

무인선은 사람이 탑승하지 않기 때문에 회수에 어려움이 있다. 본 연구에서는 무인선의 회수를 용이하도록 하기 위하여 히빙라인 발사장치를 개발하였고, 히빙라인 발사장치 이용에 대한 검증을 위하여 해상시험을 수행하였다. 무인선 회수 시스템은 히방리인 발사장치, 견인장치, 크레인-무인선 결합장치, 원격조종기로 구성되어 있고, 히빙라인 발사장치는 발사관, 원격 격발장치, 공기통, 견인탄과 히빙라인으로 구성되어 있으며, 히빙라인 발사장치는 원격조종기를 이용하여 모선에서 제어가 가능하다. 제작된 히빙라인 발사장치를 유인선에 설치하여 실제로 해상에서 사용이 가능한지 검토하였다. 히빙라인을 원격으로 발사하고 모선에서 크레인을 이용하여 무인선에 결합하는 해상시험을 수행하였으며, 해상시험을 통하여 히빙라인 발사장치의 유용성을 확인하였다.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2002.05a
• /
• pp.83-88
• /
• 2002

This study is to provide the experimental information and basic data on heat transfer characteristics of horizontal liquid film driven by hot wind. Heat transfer characteristics of the liquid film in the rectangular duct was observed and the change of film temperature was measured. The experiments were carried out for a variety of parameter, such as feed water rate and velocity and temperature of feed air. From the observation and the measurement the general understanding of heat transfer characteristics for liquid film driven by hot wind was provided.

• Journal of the Korean Institute of Gas
• /
• v.5 no.4 s.16
• /
• pp.8-20
• /
• 2001

Neoliberalism became a catch word of a post-cold war era. It began to develop in the middle of welfare state crisis in developed countries. It promoted both a unified world market through mutual penetration of national boundaries in International scene and maximization of efficiency through market competition in domestic scene. Privatization of public corporations is a major policy to pursue market efficiency through deregulation. Two reasons are often adduced to support the cause The socio-economic changes diminished the necessity to establish public corporation on the one hand. On the other hand gross inefficiency has been observed in the management of public corporation. 'Government failure' is an apt expression of the inefficiency. In analysing the experiences of privatization of utility industries of some other countries we found a couple of lessons for a Korean case. First, it is doubtful if privatization, that is a change in the form of ownership, is a necessary condition for achieving market efficiency. Because it is possible to operate a mechanism of market competition while maintaining competition among public corporations and with private actors. Second, the patron-agent dilemma is often cited as a major culprit of an inefficient management of public corporations. But it is without saying that the dilemma is also found in the management of private firms. So, the issue is not the privatization per se but to realize responsible management through discipline and incentives.

• Korean journal of applied entomology
• /
• v.40 no.3
• /
• pp.219-226
• /
• 2001

To identity the composition and ratio of the sex pheromone in the asiatic leafroller, Archippus breviplicanus (Walsingham), which is a major pest on apple leaves, and to develop a monitoring system using this sex pheromone, abdominal tips of their virgin female during the calling period were extracted and analysed. The GC/GC-MS analysis revealed the following three compounds; (E)11-tetradecenyl acetate (E11-14: Ac), (Z)11-tetradecenyl acetate (Z11-14: Ac), and tetradecyl acetate(14: Ac) with the ratio of 56:22:22. Electroantennogram (EAG) assay was also conducted to examine biological activity of the components. The three components evoked significantly higher responses than hexane or air but there was no significant differences between the mixtures made by components. Field trapping experiments for determining the optimum blend, seasonal fluctuation and the optimum amount for male attracting were carried out over 4 years from 1997 to 2000. Although male moths were attracted to 8:2 and 7:3 between E11-14: Ac and Z11-14: Ac, their 7:3 blend was found to be the most effective. Archippus breviplicanus appears to occur three times a year in Korea. The optimum amount for monitoring was found to be 1mg per trap. 14: Ac, the third component, did not show synergistic effect on male moth attraction.

• Journal of Energy Engineering
• /
• v.24 no.3
• /
• pp.82-88
• /
• 2015

After a reheating furnace installation, the modification of the size and the heat capacity is very difficult. Therefore, the development of design package tool is required for the computation on the correct specifications before the design and the installation. Prior to development of the design tool, a module that calculates the amount of heat loss of each part according to the specifications for determining the thermal efficiency of a continuous heating furnace was developed and applied to the oxy-fuel industrial furnace. Through this, the effects of fuel type, oxygen fraction and recirculation on the efficiency of the furnace of which the output is 110Ton/hour were analyzed. In oxy-fuel combustion condition, the efficiency was 15% higher than air combustion conditions. With the using COG(Coke Oven Gas) instead of LNG, the efficiency was slightly increased. In the air combustion condition, the efficiency was increased about 33% with the preheated air. But, in oxy-fuel condition, the amount of exhaust gas was reduced, so the efficiency was increased about 7%.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.7
• /
• pp.683-687
• /
• 2012

The purpose of this paper is to numerically study the characteristics of the indoor air flow of a square ceiling type diffuser according to the vane angle and flow rate. The CFX of ANSYS 13.0 was used for the CFD tool. The size of the room is $6m(X){\times}6m(Y){\times}2.7m(Z)$. The exhaust diffuser was positioned diagonally to the supply diffuser. This diffuser was designed to have many holes, so the air supply had long throw patterns with low velocity decay. The characteristics of the indoor air flow was studied at volume flow rates of 5.1 CMM and 7.4 CMM, and a vane angle from $30^{\circ}$ to $60^{\circ}$, every $10^{\circ}$.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.10
• /
• pp.928-935
• /
• 2010

A bag filter system was partially burnt down during a trial run of waste wood incineration boiler. This brought about unburned hydrocarbon which caused a rapid deactivation of low temperature SCR catalyst set up in two stage after the bag filter. The deactivated catalyst was investigated in order to trace the origin by several characterization methods such as XRD, EDX, BET, TGA, SEM. The deactivated catalyst was regenerated by different methods such as acid washing, water washing in ultrasonication, and calcination treatment under air condition. It is found the calcination treatment under air condition at $450^{\circ}C$ for 2 hours to be the best regeneration method. The catalytic activity was measured in the form of 2 cm ${\times}$ 2 cm ${\times}$ 10 cm (catalyst weight 10 g) honeycomb type. A deNOx efficiency of the regenerated catalyst showed 100% at $180^{\circ}C$ which is the same level of fresh one.

• Environmental and Resource Economics Review
• /
• v.32 no.2
• /
• pp.77-105
• /
• 2023

This paper investigates the management stability of KOSPI-listed energy public enterprises from the perspective of median voter theory. We analyze the profitability and stability of five energy public enterprises during the period 2011~2022, and conduct an empirical analysis to determine whether they are related to the preferences of median voters who can represent the general public. Our analysis of the profitability and stability of the energy public enterprises shows that the stability of their has been deteriorating in recent years. The results of the empirical analysis also show that the management stability of the energy public enterprises is related to the preference of median voter. Specifically, they indicate that when the median voter's income is smaller than the average income, the profitability of the utility decreases and the debt ratio increases. This paper suggests that from the median voter's point of view, excessive utility and energy bills may strengthen the incentives for governments and politicians to suppress rate increases, leading to lower profitability and higher debt for public enterprises.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.06a
• /
• pp.81-86
• /
• 2005

The purpose of this study is to develop venturi type after-burner in order to obtain pollutant reduction effect and find the best stable combustion condition. For this purpose, through a flow analysis, the shape of venturi type was made and flame holder locations were also decided by measuring chemical species at before and after the after-burner. Also, various chemical species concentration were measured at changing the induced air rates and the oxygen for oxygen enrichment for the solution the problems of much oxygen flow rate and the flame stability range. As results of this study, a flow distribution and the purification effect was excellent at venturi contraction 0.5 and flame holder location 12mm below the center of Venturi throat. On the purification characteristics, we found that pollutants reduction was effective when area ratio and oxygen are increased. But there are suitable quantities due to the flame shape change and combustion efficiency.