• Title/Summary/Keyword: 환기 해석

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Study of apartment plan technology adopting structural element of Hanok (공동주택에 적용 가능한 한옥 평면기술에 관한 연구)

  • Park, Kyung Hyun;Roh, Young-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.10
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    • pp.6366-6371
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    • 2014
  • This study examined the structural elements of Korean-style houses (Hanok) and proposed formula accounting for their similar patterns and regular behavior. The design of modern apartment buildings adopts many aesthetic elements from Hanok but those are only for interior decoration. In this study, the projected Hanok eaves were examined in terms of the length of solar insolation. Leaning pillars toward the inside of the building were analyzed in detail not only for the front and back pillar, side pillar, but also the corner pillar. This study also suggested a design element from the Hanok structure, such as the elevated balcony, porch flooring, and inner garden in porch area. In addition, the new apartment plan improved air circulation, ventilation and natural lighting.

A Study of Cooldown Performance of Shutdown Cooling System of Korea Next Generation Reactor (차세대 원자로 정지냉각계통의 냉각 성능에 대한 연구)

  • 유성연;이상섭
    • Journal of Energy Engineering
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    • v.8 no.4
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    • pp.525-532
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    • 1999
  • The standardized Korea Next Generation Reactor (KNGR) NSSS has developed in the basis of the ABB-CE System 80+ design concept. In this study, several regulatory requirements for the KNGR shutdown cooling system (SCS) operation are investigated. The purpose of this study is to establish the technical self-reliance for SCS design by supporting fundamental data such as SDCHX effective area and reactor CCW flow rate. Thermal power of KNGR would be increased to about 4,000 $MW_{th}$ in comparison with thermal power 2.825 $MW_{th}$ of UCN 3&4, therefore, SCS design data shall b recalculated by using the KDESCENT Code, which could evaluate cooling capability of SCS. It is found that SCS minimum flow rate is able to remove the primary sensible heat. Reviewing the major components such as heat exchanger, pump, value, and operating procedure, it is concluded as follows.

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A Study on Heat Transfer Enhancement for a Shear-Thinning Fluid in Triangular Ducts (삼각형 단면 덕트 내의 Shear-Thinning 유체에 대한 열전달 촉진에 관한 연구)

  • Lee, Dong-Ryul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.3808-3814
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    • 2011
  • The prediction of heat transfer and pressure drops in the exchanger passages is a clue to the problem of heat exchanger design. In order to make such predictions for non-Newtonian fluids, it is necessary to know the relation between the viscous properties of the fluid and the wall shear rate in the duct. This study deals with the limits of validity of the power law equation. The useful methodology of the present research involves a consideration of a more general equation which has power law and Newtonian behavior as asymptotes. It isconcluded that use of the power law equation outside of its applicability range can lead to serious errors inpredicting the heat transfer and pressure drops. The present computational results of the friction factors times Reynolds number for shear-thinning fluid flows in a triangular duct are compared with previous published results, showing agreement with 0.13 % in Newtonian region and 2.85 % in power law region. These shear-thinning fluid results also showed the 12% increase of convective heat transfer enhancement compared with Newtonian heat transfer.

Analysis of the Characteristics of Flue Gas in Infrared Mobile Heaters for Gas Room Heating (가스난방용 적외선 히터의 연소배기가스 특성해석)

  • Kim Young-Gyu;Kwon Jeong-Rock;Kim Chung-Kyun
    • Journal of the Korean Institute of Gas
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    • v.2 no.1
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    • pp.66-73
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    • 1998
  • This paper deals with the combustion characteristics of flue gas in infared mobile heaters. The experimental work has been performed to obtain the concentration levels and combustion characteristics of flue gas with varying chamber size and room temperature. The experimental results showed that oxygen depletion sensor device was operated at the oxygen concentration level of $18.3\%$ for all the chamber size. The combustion characteristics of oxygen and carbon dioxide show a linearity After 10 minutes the combustion property of carbon monoxide occurs at random without a level of oxygen and carbon dioxide in closed space of the heater. In these results, it is very important to prevent incomplete combustion through a sufficient ventilation, and accident prevention with a reduction of the oxygen and diffusion of toxic carbon monoxide.

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A study on cross sectional characteristics and available area for using the lower space in TBM road tunnels (TBM 도로터널의 단면특성 및 하부공간 활용을 위한 유효면적 검토)

  • Kim, Hyun-Soo;Kim, Hong-Moon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.2
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    • pp.141-157
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    • 2012
  • For the application TBM tunneling method, Both tunnel design standard and case study designed & constructed in domestic and foreign have been conducted. According to the study, the number of lane and inner shape (single or duplex) vary depending on the volume of traffic. Also extra space located in the top and bottom of tunnel is used for a multipurpose such as ventilation, disaster prevention, maintenance and administration. To find area ratio according to the components of road TBM tunnel, a standard section was considered as a two-lane road. Then, the analysis of area ratio of this section which consists of components for clearance, extra space in upper and lower tunnel was carried on two widths of shoulder. In addition, after a structural analysis, a thickness requirement of lower slab which is essential for road tunnel was derived on a few supporting types. Through correlation analysis, the ranges of available cross-sectional area between slab thickness and lower extra space of the tunnel was presented.

Investigation of Transient Performance of An Auxiliary Power Unit Microturbine Engine (보조동력용 마이크로터빈 엔진에 대한 과도성능 해석)

  • Son, Ho-Jae;Kim, Soo-Yong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.11 no.3
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    • pp.20-28
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    • 2007
  • The easiest way to see the phenomena of compressor surge is to show the static and dynamic operation characteristic on the map. Its operation zone will be restricted by the surge limit and, static and transient process must have some margin for it. Effect of rotor moment of inertia, air/gas volumes and heat transfer are factors to cause the transition from the static line. In case a large volume such as heat exchanger exists in the system it will exert a substantial influence to dynamic characteristics. In the present paper, influence of air volume bled from the compressor exit on transient process is investigated with an example of an auxiliary power unit micro-turbine engine. Turbine mass, pressure ratio, rotation speed, power and moment are calculated based on mass and work conservation. Result from the present study can give guidance to design the control system. A computer program is developed to calculate the dynamic process using the MathCAD commercial software.

Changes in Fire Characteristics according to the Distance Between the Fire Source and Sidewall in a Reduced-Scale Compartment (축소 구획실에서 화원과 측벽의 거리에 따른 화재특성 변화)

  • Yun, Hong-Seok;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.33 no.1
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    • pp.50-59
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    • 2019
  • Experimental and numerical studies on the fire characteristics according to the distance between the fire source and sidewall under the over-ventilated fire conditions. A 1/3 reduced ISO 9705 room was constructed and spruce wood cribs were used as fuel. Fire Dynamics Simulator (FDS) was used for fire simulations to understand the phenomenon inside the compartment. As a result, the mass loss rate and heat release rate were increased due to the thermal feedback effect of the wall in the compartment fire compared to the open fire. As the distance between the fire source and sidewall was reduced, the major fire characteristics, such as maximum mass loss rate, heat release rate, fire growth rate, temperature, and heat flux, were increased despite the limitations of air entrainment into the flame. In particular, a significant change in these physical quantities was observed for the case of a fire source against the sidewall. In addition, the vertical distribution of temperature was changed considerably due to a change in the flow structure inside the compartment according to the distance between the fire source and sidewall.

Valid Algorithm for Short Distance based on Mnemonic System in Mobile Environments (모바일 환경에서 기억법 기반 짧은 거리 유효 알고리즘)

  • Kim, Boon-Hee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.2
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    • pp.301-306
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    • 2021
  • In the field of year-based interpretation of important data, memory laws can be used as a way to enhance educational effectiveness. Studies related to how to remember numbers are conducted in the form of increasing memory rates by presenting information in the form of conventional simple images. We attempt to supplement the method proposed in the paper of numerical algorithm for modifying errors based on mnemonic system in mobile environments. We want to complement the error correction numerical algorithm proposed in previous work. The study was a way to compensate the errors that occur when users enter numerical information in the apps they use. In this work, we want to increase the memory rate based on two-dimensional information by imposing the concept of angles, rather than simply showing data to help recall memories from mistakes. To this end, we propose a problem-solving process using developed app, and implement and evaluate the short distance valid algorithms.

Proposal of finger splint design using design guidelines to reflect user requirements - Using FDM 3D printing technology - (사용자의 요구조건을 반영 할 수 있는 디자인 가이드라인을 이용한 손가락 보조기 디자인 제안 - FDM 방식의 3D 프린팅 기술을 이용하여 -)

  • Shin, I Yeol;Oh, Kwang Myung
    • Design Convergence Study
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    • v.18 no.3
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    • pp.1-14
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    • 2019
  • General finger splint manufactured and sold domestically could have been of great help to patients with disabilities due to damage to the body's. However, it reminded the wearer of his disability that he wanted to hide. This has had a negative effect on the psychological side of self-absorption and depression. If this avoids or rejects wearing, the role of ancillary rehabilitation is lost. This does not meet the user's requirements. Thus, in this study, 3D printing was used to better reflect user requirements. Next, the study examined existing prior studies to identify the characteristics and criteria of each study. It also examined medical finger aids that were being sold in the auxiliary device market. The assessment criteria were derived by compiling and interpreting user surveys of each finger splint device. Based on the evaluation criteria derived, the design guidelines for finger splint were presented using FDM-style 3D printers. Finally, we proposed a finger splint design according to the proposed design guideline.

A Qualitative Study on the Use of Fallacies in the 2022 Korean Presidential Debates (20대 대선 후보 TV토론에서의 오류 사용에 관한 질적 연구)

  • Heo, Man-Sup
    • The Journal of the Korea Contents Association
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    • v.22 no.10
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    • pp.676-690
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    • 2022
  • The present study aims to explore how fallacies, arguments that seem valid but are not, appear in 2022 South Korean presidential debates. It qualitatively analyzes the candidates' remarks in the first and last presidential debates (240 minutes) using 20 formal and informal fallacy concepts as a theoretical framework. Results show that the three candidates used 23 informal fallacies from 15 categories, including the straw man, red herring, begging the question, complex question, hasty generalization, appeal to the masses, and you too. The candidates relied on fallacies to defend their image and electoral agenda from adversary attacks and to contaminate their opponent's image and agenda. The arguers, who struggled with tough questions, frequently made fallacies as pseudo-arguments to avoid the situation without lying and violating election laws. This study indicates that the fallacy system can be a framework for analyzing crucial political content. Moreover, it warns against the abuse of fallacies in TV debates.