• Title/Summary/Keyword: Tower design

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Development of Vertical Separated Tubular Steel Pole (종방향 분할형 관형지지물 개발)

  • Lee, Won-kyo;Mun, Sung-Duk;Shin, Kooyong
    • KEPCO Journal on Electric Power and Energy
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    • v.5 no.4
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    • pp.257-262
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    • 2019
  • Lattice steel towers for overhead transmission lines have been replaced by tubular steel poles due to the visual impact of large and complex shape of truss type. Demand for tubular steel poles consisting of a single frame member continues to grow because of its advantages such as visual minimization, architectural appeal and minimal site consumptions. However, there are some constraints on the transportation and construction. As the diameter of tower base has been enlarged, it may exceed minimum height limit required to pass the tunnel in case of land transportation. Also, in a narrow place where it is not easy to secure the installation areas such as mountainous places, there might be some areas wherein it must secure a wide working space so that large vehicles and working cranes will be allowed to enter. In this paper, we presented a vertical separated tubular steel pole, which is a new type of support that can be implemented for general purpose such as mountainous areas or narrow areas to improve the issues raised by breaking away from the conventional design and fabrication methods. Technical approaches for overcoming the limit of the cross-sectional size is to separate and modularize the cross-section of the tubular steel pole designed with a size that cannot be carried or assembled, and to lighten it with a weight capable of being transported and assembled in a narrow space or mountainous area. As a result of this research, it will be possible to enter small and medium sized vehicles in locations where it is restricted to transport by large-sized vehicles. In the case of mountainous areas, it will be possible to divide it into a weight capable of being carried by a helicopter and it will be easy to adjust and fabricate it with individual modules. Furthermore, in order to break away from the traditional construction method, we proposed the equipment that can be applied to the assembly of Tubular Steel Pole without using a large crane in locations where there is no accessible road or in locations wherein large cranes cannot enter. In particular, this paper shows the movable assembling equipment and some methods that are specialized for vertical separated tubular steel pole consisting of members with reduced weight. The proposed assembly equipment is a device for assembling the body of the Tubular Steel Poles. It will be installed inside the support and the modules can be lifted by using the support itself.

A Study on Maximum Responses of Rotational Shells Subjected to Uneven Settlements by Stochastic Method (부등침하를 받는 회전 쉘의 최대응답 추정에 관한 연구)

  • 정명채
    • Computational Structural Engineering
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    • v.10 no.3
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    • pp.175-184
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    • 1997
  • The objective of this paper is to study arelationship between maximum response and its standard deviation of rotational shells that are subjected to uneven settlements. For this, the ratio, .eta, of the maximum response to standard deviation and it's approximate, .eta./sub apr/, are investigated by stochastic methods. Also, an equation for .eta./sub apr/, that is a function of predominant harmonic number is suggested. The settlements are represented by the Fourier series. Each term in the series contains two coefficients; the amplitude and the phase angle. It is assumed that phase angles are random variables and amplitudes are deterministic. To investigate the characteristics of .eta. and .eta./sub apr/, 100 phase angles for two types of artificial amplitudes spectra are used in the analysis. .eta. and .eta./sub apr/, are almost constant regardless of amplitude type, position of a shell or type of responses; they fall into from 2.0 to 2.5. .eta./sub apr/ is always close to .eta., but tends to be somewhat greater. It may be concluded that a maximum responses of rotational shells subjected to uneven settlements are .eta./sub apr/ (about 2.5) times of its standard deviation. It is considered that this result is used when we design rotational shell structures subjected to differential settlements.

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The Effect of Supportive Group Nursing Care on Body Image of the Patient With tower Limb Fracture (지지적 집단간호가 하지골절 환자의 신체상(Body Image)에 미치는 영향)

  • 정추자
    • Journal of Korean Academy of Nursing
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    • v.15 no.3
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    • pp.74-80
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    • 1985
  • This study was attempted to identify the difference between body image of the patients with lower limb fracture and that of normal persons, and to examine if supportive group care could offer an apportunity for positive change in body image of the patient with lower limb fracture under the Quasi-experimental design. The subjects for this study were obtained by ta-king convenient sample of soldiers; the experimental group were 44 lower limb fractured patients hospitalized on the orthopedic Surgery unit in S Army General Hospital, while the control group were 44 normal enlisted men serving in the B Army regiment. Supportive group nursing care was given to the lower limb fractured patients who belong to the experimental group. Pre-and post-tests were administered to the experimental and the control group. The instruments to measure body image of the subjects were body Cathexis Scale developed by Scord and Jourard (1953) and Body Meaning Scale dove-loped by the reseacher. The reliability coefficients by Cronhach's u-test were .95 in body Cathexis Scale and .89 in Body Meaning Scale in this study. Data for this study were collected over a period 12 days from the 12th to the 24th of October, 1984 by the questionnaire. Data were analyzed by computer. Frequency, Percentage and x²-test were used to examine general chacteristics of the subjects. t-test was used to analyze the hypotheses. Analysis of variance was used to test difference in body image between groups classified by the general characteristics. Pearson Correlation Coefficient was used to identify the correlation between Body Cathexis Scale and Body Cathexis Scale and Body Meaning Scale. The results of this study were as follows: 1. No significant difference was found between the experimental and the control group on general characteristics of the subjects (p> .05). 2. Hypothesis I:“There will be a difference in body image between patiens with lower limb fracture and normal persons,”was supported(Body Cathexis t=6.91, p<.001, Body Meaning t=5.66, p< .001). 3. Hypothesis Ⅱ;“The will be a difference in body image of patients with lower limb fracture bet-ween after and before, supportive group nursing care was provided,”was supported (Body Cathexis t=5.90, p<.001, Body Meaning t=4.45, p <.001). 4. There was no significant difference in body image between groups classified by the general characteristics (p> .05). 5. The correlation between Body Cathexis Scale and Body Meaning Scale: It was reported that Body Cathexis Scale correlated with Body Meaning Scale in total subjects of the experimental and control group (r=.744, p<.001). That is, there was relatively high correlation between two scales. body Cathexis Scale correlated with Body Meaning Scale in the experimental group(r=.738, p <.001) and in the control group (r=.352, p <.001). That is, there was more than moderate correlation between two scales. In conclusion, it was found that there was a difference in body image between patients with lower limb fracture and normal persons, and supportive group nursing care offered an opportunity for positive change in body image of the patient with lower limb fracture.

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Analysis of the Gas Feed Distribution at the Gas Sweetening Absorber Using CFD (CFD를 활용한 산성가스 처리공정용 흡수탑 가스분산성 향상 연구)

  • Lee, Ji Hyun;Shim, Sung-Bo
    • Korean Chemical Engineering Research
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    • v.52 no.3
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    • pp.314-320
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    • 2014
  • Regarding the design of the gas sweetening absorber, the gas distribution analysis for the increase of the sour gas removal and reduction of the tower height is very important research topics. Recently, regarding the $CO_2$ capture technology which is a promising option for the reduction of the greenhouse gas (GHG), the need for the gas distribution improvement is increased as the gas treating capacity increases. In this paper, we have investigated the sour gas distribution in the absorber using CFD (Computational Fluid Dynamics) based on 10 MW post-combustion $CO_2$ capture plant installed in Boryeong power station, Korea Midland Power company. For this purpose, we suggested the three possible technology options (splash plate, spiral gas line and U-tube) for the gas distribution enhancement and compared the effect of the each cases. The result showed that the U-tube installed in the absorber increase the gas distribution about 30% compared to the base case, while the delta P increasement was about 10%. From these results, it was found that the U-tube installation is an effective technology option for the gas distribution enhancement in the gas sweetening absorber.

An Experimental Study on Pumpability Characteristics of High Strength Concrete Mixed Polymix (폴리믹스 혼입 고강도 콘크리트의 펌프압송 성상에 관한 실험적 연구)

  • Lee, Joo-Ho;Moon, Hyung-Jae;Kim, Jeong-Jin
    • Journal of the Korea Concrete Institute
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    • v.24 no.5
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    • pp.509-516
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    • 2012
  • The aims of this research is to develop a fire resistant admixture to enhance high-pressured pumping of high-strength concrete (HSC) with a compressive strength of 60~80 MPa. Generally, the efficiency of HSC high-pressured pumping is dramatically reduced due to entanglement of short fibers added to prevent fire spalling. Therefore, the fire resistant admixture that can facilitate pumping of fire resistant HSC is urgently needed presently. The fire resistant HSC mix is comprised of Polypropylene fiber, Nylon fiber and Polymer powder. The test results showed that the slump-flow was improved by approximately 70% of the HSC without fire resistant admixture. However, the air void content was increased slightly due to the addition. The standard design compressive strength at 28-days was satisfied, while its flexural strength was similar to the concrete without the admixture. Since the flexural strength was 12~15% of its compressive strength, the general trend of flexural to compressive strength ratio in normal concrete was maintained. Even though its elastic modulus was decreased by adding the admixture, the study results showed that the concrete can be used for construction since all of the test results exceeded the code requirements.

Design of waste Sludge/Food Waste Biological Treatment Process using Closed ATAD System (밀폐형 ATAD system을 이용한 하수슬러지/음식물쓰레기 통합처리 공정 설계)

  • Kwon, Hyeok-Young;Ji, Young-Hwan;Song, Han-Jo;Kim, Seong-Jung
    • Journal of the Korea Organic Resources Recycling Association
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    • v.8 no.4
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    • pp.129-137
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    • 2000
  • In this study, biological treatment process of MWWT(Municipal wet-waste Treatment) has been developed through a moduling of the containerized closed ATAD(Auto thermal aerobic digestion) system & closed vertical dynamic acerator, which were used for food waste and cattle manure, respectively. Though biological process has several advantages such as low concentrations of heavy metals and salts, proper and stable C/N ratio and constant reaction rate against the process treating two wastes separately, it has a obstacles of salt concentration and much usage of bulking agent such as wood chip. After rapid oxidation in the boxed tower reactor for 5 days, the content of sewage sludge would be reduced 65% on around, might be mixed with the food waste that had been treated in the static closed reactor during 6 days and put in the secondary static reactor for curing. During composting process, the odor contained in the gas generated from the reactor was removed by passing it through a biofilter as well as the leachate was treated in the wastewater treatment facility. Consequently, it seemed to be possible to compost sewage sludge at mild and stable operating condition and at low cost through the biological ATAD process resulting in the production of organic compost satisfying the specifications regulated by itself.

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Korea's Free Economic Zone as an Economic Development Strategy and Operational System (경제발전전략으로서 한국의 경제자유구역과 운영체계에 관한 연구)

  • Koh, Eui-Hyeon
    • Journal of Distribution Science
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    • v.12 no.9
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    • pp.113-123
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    • 2014
  • Purpose - After Korea's Free Economic Zone (FEZ) system was launched in 2003, there have been many debates about upgrading it and its support systems. However, as of 2013, there were insufficient results. Further, upon the designation of the East Coast and Chungbuk as official FEZs from February 4, 2013 by the 56th the Commission, there is a concern that many people are in the area designated as FEZ 8. This study investigates Korea's new FEZ system as part of Korea's primary new economic development policy in the 21st century. Therefore, this study examines views on the weaknesses of the past ten years of FEZs so that Korea can expand its FEZ system. Research design, data, and methodology -Many countries have considered the FEZ as an economic special zone. By reviewing previous research models, this study provides an update using recent data and materials, until 2013, from the Center of Free Economic Zones. In previous studies, the lack of support systems was attributed to proposals to ensure operational autonomy and differentiation of each FEZ; however, the main cause cannot be solved through regulatory issues, as difficulties caused by the operational system are responsible for the problems. We wish to analyze the FEZ, specifically the operational system; this is the main issue of this study. Results - After the first FEZs were established, it became necessary to have basic plans, as investment results in 2013 compared to the same period this year led to lower earnings in the first half of 2014. We propose an improvement of the operational system because in the free economic zones, the operational system is the root cause of the underlying problem. The results of this research are as follows. The weak management of the FEZ system is influenced by weak investment, delayed development, foreigners' living facilities, benefits of foreign investments, the control tower's policy making decision process, quickness of the process of satisfying legal requirements, and support For the independence of FEZs. Conclusion - Local governments do not have legal rights over FEZ deregulation and investment industries. This study suggests that the local government should have more independence from the central government. Moreover, independent management committees are more effective for ensuring public rights, better employee responsibilities, and better-qualified personnel. The FEZ committee struggles to effectively manage the locations of FEZs, foreign investments, and related facilities under the control of the Ministry of Trade, Industry and Energy. Thus, the FEZ committee should be under either the Prime Minister's office or the Presidential committee, to control and effectively coordinate between the local and central governments. If the problem clearly applies to the operational system in 2013, it is necessary to provide materials and methods so that the results of the first half of 2014 can be computed despite the data limits and lack of resources, and the data can be analyzed in a more diachronic thesis.

A Study on Identifying Problems by the Comparative Analysis of High-Rise Apartment Evacuation Design Codes (고층 아파트 피난설계기준 비교분석을 통한 문제점 도출 연구)

  • Hwang, Eun-Kyoung;Seo, Dong-Goo
    • Fire Science and Engineering
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    • v.31 no.6
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    • pp.47-52
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    • 2017
  • The recent tragic outbreak of fire at the Grenfell Tower in the United Kingdom compels all branches of government to reexamine and reassess the safety measures against fires in high-rise buildings from a broad perspective. Accordingly, this study examined what problems stem from the current evacuation codes by comparative analysis of the high-rise apartment evacuation codes that range over various individual laws before introducing a new evacuation code. The outcome of this study can be utilized as basic data for amending the existing evacuation codes for high-rise buildings. The codes related to high-rise building evacuation include the Building Act, the Housing Act, the Skyscraper Disaster Management Act, and the Fire-Fighting System Act. Some local governments have also drawn up their own codes and put them into practice. Comparative analysis of the major evacuation codes has helped identify a variety of problems, such as different codes being applied to each individual law and ordinance, the use of additional codes other than the provisions of laws and ordinances, and the in effectiveness of evacuation codes. Most of these problems occur when diverse codes are applied to a single building, which means that cooperation among the relevant ministries is urgently needed to improve the related codes in the future.

Environment as an Indicator in the Buddhist Art of Asia (아시아 불교미술에서 지표로서의 환경)

  • Lee, Jung-Hee
    • Journal of Science of Art and Design
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    • v.13 no.1
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    • pp.61-86
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    • 2008
  • Buddhism and Buddhist art originated in India, but when they were introduced to different countries, they created an international environment. Buddhism was introduced as cultural package, with written texts, visual images, rituals, and the organization of monasteries. Buddhist art originated in India during the reign of King Asoka and then was developed under the political, intellectual, artistic, religious, social and natural environments of the regions. The stupa and the chaitya halls create monastic environment. The natural environment of the trade routes and caravans in the Central Asian deserts preserved brilliant-colored murals and helped spread tram India to China. When Buddhism and Buddhist art were introduced to China, Korea, and Japan, Buddhism became a part of government institution and social organization. Gigantic statues were carved in caves in mountains for political purposes. The Chinese transformed the stupa into a square pillar and created pagodas with tiled roofs in tower forms. Koreans not only transmitted the Buddhist art from China to Japan, but it also changed it with originality in the iconography of the pensive bodhisattva images and in the architecture of Seoggulam. The official ideology of Neo Confucian philosophy brought the rise of Chan Buddhism. Zen monasteries in Japan created unique environments by establishing the Zen Buddhist garden. to prompt believers to meditate. An important development in Buddhist art is the Esoteric Buddhist art in China and Tibet. This category belongs to the intellectual, religious as well as artistic environments. The Tibetan deities with consorts in their embrace symbolize the union of the god and the devotees. Buddhist art created a unique environment that was spread out to many nations and changed greatly over time.

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Analysis of the Effectiveness of Emergency Response Measures during the Design Basis Accident of the Research Reactor 'HANARO' using MACCS2 Code (MACCS2 코드를 이용한 연구용원자로 '하나로' 설계기준사고시 비상대응조치 효과분석)

  • Lee, Goan-Yup;Kim, Jong-Su;Lee, Hae-Cho;Kim, Bong-Suk
    • Journal of Radiation Protection and Research
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    • v.39 no.2
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    • pp.109-117
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    • 2014
  • Nuclear emergency planning is to plan sheltering, evacuation and iodine prophylaxis for the residents living in the area where the emergency plan is needed, the area is confirmed based on the dose assessment using the source-term through an accident analysis and the data measured from meteorological tower. In this study, the does change before and after protective measures was assessed stochastically based on the one year meteorological data in the condition of the maximum hypothetical accident which can be considered at the research reactor 'HANARO', and the optimized protective measures were derived based on the reference levels defined as a residual dose by ICRP 2007 recommendation which can be applied in a emergency exposure situation. The optimized protective measures for the HANARO in the maximum hypothetical accident were the evacuation to radius 300 m, the sheltering from 300 m to 800 m, the iodine prophylaxis only for the emergency workers under the protective measures for non emergency workers.