• Title/Summary/Keyword: Complex enclosure

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A Study on the Priority Ranks to Improve Work Environments in the Worker's Point of View (작업환경 소음 개선을 위한 작업자 관점의 우선순위 파악에 관한 연구)

  • Kim, Hwa-Il
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.15 no.3
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    • pp.202-212
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    • 2005
  • This study was aimed at rating the existing work environment noise components and alternatives in point of worker's view. To answer the purpose, AHP(Analytic Hierarchy Process) method is adopted in this research. Based on the AHP method, this research abstracts a mathematically rigorous noise components and alternative's weights and proven process for priority and decision-making. By reconstructing complex hearing conservation programs to a series of pair-wise comparisons, and then synthesizing the results, this study not only helps establishments of noise countermeasure, but also provides a clear rationale for noise alternatives. The result of this study is summarized as follows; 1) Job satisfaction index and noise identification index are 63, 56 respectively. 2) Noise level(15.7%), frequency(14.1%) and directivity(13.6%) are main reasons in worker's ground. 3) There are some difference between the estimation of worker's identification and that of work sites. 4) Low noise machine(14.7%), enclosure(13.2%) and shielding(9.6%) are chosen for noise protection method by workers. 5) Noise environment improvement should be focused on noise source rather than personal protection. 6) By the AHP method, noise source countermeasure have a key role at work environments.

ONE-DIMENSIONAL ANALYSIS OF THERMAL STRATIFICATION IN THE AHTR COOLANT POOL

  • Zhao, Haihua;Peterson, Per F.
    • Nuclear Engineering and Technology
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    • v.41 no.7
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    • pp.953-968
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    • 2009
  • It is important to accurately predict the temperature and density distributions in large stratified enclosures both for design optimization and accident analysis. Current reactor system analysis codes only provide lumped-volume based models that can give very approximate results. Previous scaling analysis has shown that stratified mixing processes in large stably stratified enclosures can be described using one-dimensional differential equations, with the vertical transport by jets modeled using integral techniques. This allows very large reductions in computational effort compared to three-dimensional CFD simulation. The BMIX++ (Berkeley mechanistic MIXing code in C++) code was developed to implement such ideas. This paper summarizes major models for the BMIX++ code, presents the two-plume mixing experiment simulation as one validation example, and describes the codes' application to the liquid salt buffer pool system in the AHTR (Advanced High Temperature Reactor) design. Three design options have been simulated and they exhibit significantly different stratification patterns. One of design options shows the mildest thermal stratification and is identified as the best design option. This application shows that the BMIX++ code has capability to provide the reactor designers with insights to understand complex mixing behavior with mechanistic methods. Similar analysis is possible for liquid-metal cooled reactors.

Effect of Non-Metallic Inclusions and Hot Rolling Process Parameters on Hydrogen Induced Cracking of Linepipe Steels (라인파이프 강재의 수소유기균열에 미치는 열간압연 공정변수의 영향)

  • Koh, Seong Ung;Jung, Hwan Gyo;Kang, Ki Bong
    • Korean Journal of Metals and Materials
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    • v.46 no.4
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    • pp.257-266
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    • 2008
  • AHydrogen induced cracking (HIC) was phenomenologically studied in terms of the effect of nonmetallic inclusions and hot rolling process parameters. By comparing the level of non-metallic inclusions in two different kinds of commercial grade steels having different HIC resistance, the role of non-metallic inclusions in HIC occurrence was investigated. Change in inclusion morphology and distribution during hot rolling was also studied throughout slab, rolling at austenite recrystallization region (roughing mill; RM) and rolling at austenite non-recrystallization region (finish mill; FM). In addition, the contribution of RM and FM parameters to HIC was investigated from the standpoint of change in inclusion morphology during hot rolling processes. As a result, HIC was closely related to the separation of large complex inclusion during hot rolling process. Large complex inclusions originated from the improper Ca treatment, after which equilibrium composition of slag should have resulted in eutectoid composition. By controlling the equilibrium slag composition equivalent to eutectoid one, HIC resistance could be improved due to the reduced size of inclusions. In addition, change in reduction/pass in RM had an effect on HIC resistance of steels while that in FM did not. Increase in the reduction/pass in the latter stage of RM improved HIC resistance of steels by enhancing the void enclosure around inclusions.

Study on the Space in Works of Mies Van der Rohe in Terms of Text - Focused on Tugendhat, Hubbe House and Barcelona Pavilion - (Text 측면에서 본 Mies Van der Rohe 작품의 공간성 연구 - Tugendhat, Hubbe 주택과 Barcelona Pavilion을 중심으로 -)

  • Yook, Ok-Soo
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.101-109
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    • 2014
  • It was early in the $20^{th}$ century when the space was begun to say through the mutual circumstances of form and contents. Adrian Forty explained that the characteristics of space can be divided into three steps by the period: a space of enclosure, a space as continuum and a space as an extension of the body. And there is common condition that all three spaces are accompanied by the form. In the new thinking of architectural form in terms of text in modern society, architecture becomes to more complex to understanding. Saying that there is nothing outside text (Il n'y a rien en dehors du text.) in the world, Jacques Derrida insisted the world to be texted and not to be special centrality, where can be existed by difference and delay its meaning. Text is the structural meaning (sign), not a metaphorical one (symbol). Without the symbol, the architecture can be recognized as text with signing to the form. For that, there is a question how can be explained the space in terms of text extracting the meaning and the symbol. Absolutely not intended by Mies van der Rohe, but in his works of houses and pavilion, its characteristics and traces of text can be seen. If it is possible to analyse his works in the textual view, space of Mies will be found in the same direction of text. And it will be an important opportunity to re-evaluate the space of Mies works standing in the heart of Modern Architecture.

A Study on the Application Method for the Enclosed Effect in the Space of Cities (도시공간에 있어서 둘러싸인감의 적용방법에 대한 연구)

  • Hyoung, Sung-Eun
    • Science of Emotion and Sensibility
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    • v.9 no.spc3
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    • pp.277-286
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    • 2006
  • This study evaluates how much D/H and enclosed effects are closely related with each other centering around the spaces of cities in Japan. The partial ranks of the degree of angle in D/H and of the enclosure of the real spaces which the experimenter feels are measured through the method of partial rank correlation analysis on the sane objects. The result shows that all 42 samples(0.49), 25 interior space samples(0.63), and 17 exterior samples(0.59) are analysed to be less correlated. Seen above, there is limit to explaining modern spaces with the degree of angle in D/H. The result reveals that the space structure of modem cities consists of a lot more complex elements, so it is not suitable to evaluate the spaces of cities with the past theories of D/H and enclosed effect. Therefore, to evaluate the enclosed effect, a new evaluation model and a study of influential elements of city spaces and enclosed effect should be developed.

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Does Visitation Dictate Animal Welfare in Captivity? : A Case Study of Tigers and Leopards from National Zoological Park, New Delhi

  • Gupta, Avni;Vashisth, Saurabh;Sharma, Mahima;Hore, Upamanyu;Lee, Hang;Pandey, Puneet
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.3 no.2
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    • pp.103-114
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    • 2022
  • Zoological Parks house exclusive animal species, thus creating a source of education and awareness for visitors. Big cats like tigers and leopards are among the most visited species in zoos globally. However, they often display stressful or stereotypic behaviours. Such behaviours are influenced by multiple factors including visitors, animal history, and captive environment. To understand this impact, we investigated the behavioural response of tigers and leopards to visitation, captive, and biological factors. The behaviour of eight big cats housed in the National Zoological Park, New Delhi, was monitored using focal sampling technique during May and June 2019. We recorded the captive and biological factors and visitor density for the subjects. The study revealed high proportions of inactive and stereotypic behaviours amongst the species. Tigers and leopards were found to perform stereotypic behaviours for 22% and 28% of their time, respectively. Generalised Linear Models revealed a significant variation of stereotypy in association with the factors. Stereotypy was influenced by visitor density, age, sex, breeding history, coat colour, and enclosure design. Adults, males, white-coated, previously bred, and those housed in smaller and simple enclosures display more stereotypy than young, females, normal-coated, unbred, and those housed in larger and complex enclosures, respectively. A high density of visitors induced more stereotypic behaviours amongst the big cats. As providing entertainment and awareness amongst the public is one of the fundamental objectives of the zoo, visitors can not be avoided. Thus, we suggest providing appropriate enrichments that would reduce stereotypies and promote naturalistic behaviours.

Principles and Applications of Multi-Level H2O/CO2 Profile Measurement System (다중 수증기/이산화탄소 프로파일 관측 시스템의 원리와 활용)

  • Yoo, Jae-Ill;Lee, Dong-Ho;Hong, Jin-Kyu;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.11 no.1
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    • pp.27-38
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    • 2009
  • The multi-level profile system is designed to measure the vertical profile of $H_2O$ and $CO_2$ concentrations in the surface layer to estimate the storage effects within the plant canopy. It is suitable for long-term experiments and can be used also in advection studies for estimating the spatial variability and vertical gradients in concentration. It enables the user to calculate vertical fluxes of water vapor, $CO_2$ and other trace gases using the surface layer similarity theory and to infer their sources or sinks. The profile system described in this report includes the following components: sampling system, calibration and flow control system, closed path infrared gas analyzer(IRGA), vacuum pump and a datalogger. The sampling system draws air from 8 inlets into the IRGA in a sequence, so that for 80 seconds air from all levels is measured. The calibration system, controlled by the datalogger, compensates for any deviations in the calibration of the IRGA by using gas sources with known concentrations. The datalogger switches the corresponding valves, measures the linearized voltages from the IRGA, calculates the concentrations for each monitoring level, performs statistical analysis and stores the final data. All critical components are mounted in an environmental enclosure and can operate with little maintenance over long periods of time. This report, as a practical manual, is designed to provide helpful information for those who are interested in using profile system to measure evapotranspiration and net ecosystem exchanges in complex terrain.

An Analysis on the Landscape Structure of Anuisamdong-Dongcheon in the 19th Century (19세기 안의삼동(安義三洞) 동천(洞天)의 경관구조 해석)

  • Kim, Dong-Hyun;Lee, Won-Ho
    • The Journal of the Korea Contents Association
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    • v.16 no.11
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    • pp.742-753
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    • 2016
  • This study aims to reproduce of Anuisamdong's landscape structure and improve the value of Scenic site. It was extract main spot from Geography book published by government in the 19th Century. And analyzed landscape architecture of Dongcheon. Extract main spot from Geography book published by government. Consequently, Hwarim-dong main spot 6 places, Simjin-dong main spot 9 places, and Wonhak-dong main spot 25 places were identified. Hwarim-dong's main spot was divided into 3 places of pavilion and scenery, respectively. Simjin-Dong's main spots was all that natural elements as a scenery. Wonhak-dong's main spot was the most elements of the Anuisamdong in geography book published by government. Hwarim-dong was pavilion-based scenery area complex, Simjin-dong was continues scenery spot along the valley, and Wonhak-dong was hybrid distribution that landscape structure. Each dongcheon in Anuisamdong was created a separate area through isolated geographical, visually for structure of collectively means. Also, a narrow entrance and enclosure topography are areas which arouse atmosphere of paradise. In addition, Aunuisamdong's landscape structure, which was previously divided into individual Dongcheon, was expanded into a single integrated landscape structure of Dongcheon. This is different from the general landscape development of common Dongcheon with the same starting and ending points and sightseeing routes.