• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.2
• /
• pp.253-258
• /
• 2020

Petrochemical industry complex in Korea always has high riskiness due to explosive and inflammable gases. To prevent these explosion, most facility of petrochemical industry complex requires the performance of explosive proof. The control panel, which is used as explosive proof, has been used the air injection method by manually from outside to constantly keep the temperature and pressure between inside and outside of the panel. In this paper, we propose the automatic temperature controller, which performs automatic heating and cooling according to temperature inside the panel in order to control temperature automatically.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.29 no.1
• /
• pp.35-47
• /
• 2000

최근 정부의 공기업 경영혁신계획에 따라서 민영화와 경영혁신 대상 공기업이 확장되었다. 이에 따라서, 한국지역 난방공사(이하 '한난')는 1차 민영화 대상 공기업으로서 단계적 민영화를 위하여 안양 및 부천 사업소를 한국전력공사(이하 '한전')의 열병합발전소와 통합매각하여 2001년 51%이상 지분을 매각함으로써 민영화를 완료하도록 추진방안이 수립된 상태이다. 이렇듯 가시화된 정부의 에너지산업에 대한 경쟁 촉진 및 규제완화는 정부주도의 하향식 계획을 지양하고 에너지 구성(energy mix)을 시장에서 결정되게 하자는 것이다. 이는 관련업체간에 해당에너지의 사업주체에 대한 경쟁이 아니라 개별기업이 다양한 에너지사업을 운영하면서 한 기업의 최적 에너지 구성을 시장원리에 따라서 자체적으로 결정한다는 것이 핵심사항이다. 따라서, 현재 한난과 에너지관리공단이 운영 및 소유주체로 되어 있는 국내 집단에너지사업은 정부방안에 능동적으로 대처하고, 특히 에너지산업 변화에서 제기능을 담당할 수 있도록 합리적이고 효율적인 발전계획 및 민영화 방안을 수립할 필요가 있다. 본고에서는 현재 추진중인 국내 에너지 산업 구조개편에 따른 집단에너지사업의 발전방향을 정책적인 측면에서 제시하고자 한다. 논의의 대상은 국내 집단에너지 사업으로, 공업단지 집단에너지사업을 제외한 지역냉난방 사업을 중심으로 하여 전력 및 가스사업고의 연계방안 등이 주요 사항이다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.1292-1295
• /
• 2012

인구 과밀화 및 급격한 도시 팽창은 지상공간에서 거주하는 인간 삶의 질을 위협하고 있다. 따라서 지상공간의 개발을 억제하여 환경을 보호하고 도시 공간 이용의 효율성을 최대화하기 위해 지하 공간을 개발하고자 하는 움직임이 활발하다. 자연환경으로부터 격리된 구조인 지하공간은 지상공간에 비해 실내 공기 질을 쾌적한 상태로 유지하기 어려운 밀폐된 환경이므로 오랜 시간동안 상주하는 거주자 및 한시적 이용자들의 건강에 영향을 미치는 온도, 습도, $CO_2$, 먼지 등의 환경을 제어하기 위한 기술 개발이 필요하다. 본 연구에서는 지하공간의 쾌적도 향상을 위해 온 습도 및 $CO_2$, 먼지센서를 이용한 통합 센서를 제작하여 현재 지하공간의 환경정보를 실시간 모니터링하고 실내공간의 쾌적 지표를 기반으로 환풍기, 송풍기 등의 디바이스를 제어하기 위한 USN 기반의 환경제어시스템을 구현한다. 제안한 시스템을 통해 지하공간의 환경을 개선할 뿐만 아니라 고가의 계측 장비로 인한 비용 절감 및 이동성과 확장성 등의 부가적인 효과를 기대한다.

• Land and Housing Review
• /
• v.12 no.3
• /
• pp.1-10
• /
• 2021

A public management paradigm matters for public enterprises as it has a direct impact on their business management and the performance evaluation on public institutions by the Ministry of Strategy and Finance. This research reviews key theories about public management that has attracted attention since the 1980s: New Public Management (NPM), New Public Governance (NPG), and New Public Service (NPS). These paradigms represent their unique features in terms of efficiency, networks, and public service, and have their own merits and shortcomings. This research asserts that more integrated and multi-dimensional approaches to the public management theories are needed to effectively cope with rapidly changing environments for public enterprises.

• Journal of the Society of Naval Architects of Korea
• /
• v.58 no.5
• /
• pp.271-280
• /
• 2021

The code developed using a pressure-based method for unified conservation laws of incompressible/compressible fluids is expanded to handle moving or deforming body boundaries using the hybrid Cartesian/immersed boundary method. An instantaneous pressure field is calculated from a pressure Poisson equation for the whole fluid domain, including the compressible gas region. The polytropic gas is assumed for the compressible fluid so that the energy equation is decoupled. Immersed boundary nodes are identified based on edges crossing body boundaries. The velocity vector is reconstructed at the immersed boundary node using an interpolation along the assigned local normal line. The developed code is validated by comparing the time histories of pressure and wave elevation for sloshing in a rectangular and a membrane-type tank. The validated code is applied to simulate air cushion effects in a rectangular tank under sway motion. Time variations of pressure fields are analyzed in detail as the air pocket pulsates. It is shown that the contraction and expansion of the air pocket dominate the pressure loads on the wall of the tank. The present results are in good agreement with other experimental and computational results for the amplitude and the decay of the pressure oscillations measured at the pressure gauges.

• Korean Journal of Plant Resources
• /
• v.27 no.5
• /
• pp.546-555
• /
• 2014

The final aim of this study is to develop a biofiltration system integrated with plant vegetation for improving indoor air quality effectively depending on indoor space and characteristics. However, to approach this final goal, several requirements such as constant pressure drops (PDs) and soil moisture contents (SMCs), which influence the capacity design for a proper ventilation rate of biofiltration system, should be satisfied. Thus, this fundamental experiment was carried out to adjust a proper wind speed and to ensure a stabilization of initial SMCs within biofilter for uniform distribution of SMCs and PDs, and for normal plant growth, especially avoiding root stress by wind. Therefore, we designed horizontal biofliter models and manufactured them, and then calculated the ventilation rate, air residence time, and air-liquid ration based on the biofilter depending on three levels of wind speed (1, 2, and $3cm{\cdot}s^{-1}$). The relative humidity (RH) and PD of the humidified air coming out through the soil within the biofilter, and SMC of the soil and plant growth parameters of lettuce and duffy fern grown within biofilter were measured depending on the three levels of wind speed. As a result of wind speed test, $3{\cdot}sec^{-1}$ was suitable to keep up a proper RH, SMC, and plant growth. Thus, the next experiment was set up to be two levels of initial SMCs (low and high initial SMC, 18.5 and 28.7%) within each biofilter operated and a non-biofiltered control (initial SMC, 29.7%) on the same wind speed ($3cm{\cdot}sec^{-1}$), and measured on the RH and PD of the air coming out through the soil within the biofilter, and SMC of the soil and plant growth parameters of Humata tyermani grown within biofilter. This result was similar to the first results on RHs, SMCs, and PDs keeping up with constant levels, and three SMCs did not show any significant difference on plant growth parameters. However, two biofiltered SMCs enhanced dry weights of the plants slightly than non-biofiltered SMC. Thus, the stability of this biofiler system keeping up major physical factors (SMC and PD) deserved to be adopted for designing an advanced integrated biofilter model in the near future.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.6
• /
• pp.567-575
• /
• 2011

With the development of construction information, a computerization tool for architectural process control is a necessary tool. However, the reality is that the conditions and understanding of users are not sufficient to fully utilize such a tool. In particular, it was analyzed that the reason for the negative feedback from hands-on workers regarding the current process control information system is that there is a difficulty in accessing the system for users that are not process and planning experts, due to a lack of information and technical contents at the phase of control and planning prior to the process plan. Therefore, the demands of users and a direction for the improvement of a system in terms of optimizing process control computerization were investigated, with the aim of addressing the disadvantages of the existing system and developing a professional system that is specialized in the construction industry. Therefore, it is necessary to construct an integrated WBS (IWBS) that combines WBS with CBS, and subsequently, it is judged that the most important aspect is the integrated technology of compatibility and operation of data that is linked with OBS. The process information must then deal with the changing information; in other words, the amount of construction, construction cost, and the required construction period etc., by coding data into a 4-unit index, such as a project unit (WBS Level 1), a project facility unit (WBS Level 2), a management department unit (OBS Level 1), and a control manager unit (OBS Level 2). After that, it was found that it is necessary to develop a computer system to consistently integrate process information into a management department.

• Fire Science and Engineering
• /
• v.20 no.4 s.64
• /
• pp.1-12
• /
• 2006

In this study, CFD computer simulations by FDS are carried out in order to confirm the performance of the combined operation of both sprinkler system and smoke curtain of 0.54 m depth installed for cooling and blocking the smoke which propagates beneath the sloped ceiling of a stairway corridor of which dimensions are 17.92 m long, 4.00 m wide, and 6.12 m high. It is shown that the response time of sprinklers decreases with fire size and it increases more about 1.1 second in case without smoke curtain than in case with smoke curtain, that the time of smoke transport from the fire source to the stairway outlet decreases considerably with fire size, and that the delay effect of smoke transport is not related to the sprinkler system, whether it is operated or not. This study shows that the combined operation of both sprinkler system and smoke curtain is very effective in smoke cooling, but it is a little for effect on smoke blockage. Although the hazard of skin burn due to radiative heat flux from hot smoke layer is decreased by spray cooling effect, the hazard of smoke suffocation and the weakening of visibility is increased by smoke downdrag and the turbulence of smoke-air mixing due to water spray. These conditions may result in preventing occupants from going out of the stairway during evacuation.

• Land and Housing Review
• /
• v.7 no.3
• /
• pp.137-145
• /
• 2016

This study aims to empirically verify the positive impacts of PB(performance-based) HRM on the organizational effectiveness in a public corporation. The independent variables are 'PB staffing', 'PB appraisal', 'PB compensation'. The dependent variables are 'JS(job satisfaction)', 'OC(organizational commitment)'. The results are as follows. 'PB staffing' shows positive impact on both 'JS' and 'OC', but 'PB compensation' doesn't show positive impact on both 'JS' and 'OC'. Also, it is found that both 'PB appraisal' and 'PB compensation' do not show positive impact on 'OC'. 'PB appraisal' shows positive impact on 'JS', though. From the empirical analysis, the positive effects of the PB-HRM on the organizational effectiveness are partially verified. It is thought that these mixed results are originated from the particular situation in which the surveyed corporation is placed. After the merger of the corporation in 2009, even though it has introduced various PB-HRM systems, it has been through a harsh time such as wage freeze and return as measures of business normalization. This organizational situation may influence the verification of effectiveness of the normal PB-HRM.

• Journal of the Korean Institute of Gas
• /
• v.23 no.1
• /
• pp.27-35
• /
• 2019

In order to solve the global warming and reduce greenhouse gas emissions, $CO_2$ capture technology was developed by applying oxy-fuel combustion. But there has been such a problem that its economic efficiency is low due to the high price of oxygen gases. ASU is known to be most suitable method to produce large quantity of oxygen, to reduce the oxygen production cost, the efficiency of ASU need to be improved. To improve the efficiency of ASU, exergy analysis can be used. The exergy analysis provides the information of used energy in the process, the location and size of exergy destruction. In this study, the exergy analysis was used for process developing and optimization of large scale ASU. The process simulation of ASU was conducted, the results were used to calculate the exergy. As a result, to reduce the exergy loss in the cold box of ASU, a lower operating pressure process was suggested. It was confirmed the importance of heat leak and heat loss reduction of cold box. Also, the unit process of ASU which requires thermal integration was confirmed.