• Title/Summary/Keyword: U-Value

Search Result 2,052, Processing Time 0.024 seconds

Relationship Between Physical Properties and Compression Index for Marine Clay (해성점토의 물리적 특성과 압축지수의 상관성)

  • 김동후;김기웅;백영식
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.6
    • /
    • pp.371-378
    • /
    • 2003
  • The compression index of clay distributed in the west and south coast of the Korean Peninsula had been studied. Compression index was obtained from the conventional consolidation test, and was conducted accordingly to obtain the field virgin compression curve by means of Schmertmann's graphical correction. To examine a correlation closely between physical properties of soils($e_o$, LL, w) and compression index(Cc), linen. and non-linear regression analysis were employed based on the data collected from tests. The conclusions are as follows. The compression index obtained by means of Schmereann's graphical correction is about 1.16 times for the value of original oedometer test curve for U/D samples. Non-liner regression curve was preferable to establish a correlation equation rather than linear regression curve. All derived equations so far achieved have been summarized and given. However, linear equation is better for practical use so that part by part simplified linear equations were also suggested alternatively together with their own non-linear regression curve.

The Development of Performance Evaluation Program of Building Integrated Photovoltaic System (건물일체형 태양광발전 시스템 성능평가 프로그램 개발)

  • Kim, Beob-Jeon;Park, Jae-Wan;Yoon, Jong-Ho;Shin, U-Cheul
    • KIEAE Journal
    • /
    • v.15 no.4
    • /
    • pp.85-90
    • /
    • 2015
  • Purpose: In design and planning Building Integrated Photovoltaic(BIPV) system can reduce cost by replacing building facade as construction material such as roofs, outer walls and windows as well as generating electricity. BIPV system should be applied at the early stage of architectural design. However, it is hard to decide whether using BIPV system or not for architects and builders who are not professional at BIPV system because performance of system is considerably influenced by types of module, installation position, installation methods and so on. It is also hard for experts because commercialized analytical program of photovoltaic systems is too complicated to use and domestic meteorological data is limited to partial areas. Therefore, we need evaluation program of BIPV system which can easily but accurately interpret generating performance and evaluate validity of BIPV system at the early stage of architectural design even for inexpert. Method: In this study, we collected meteorological data of domestic major region and analyzed generation characteristic of BIPV system by using PVsyst(commercialized software) in accordance with regions, types of solar module, place and methods of installation and so on. Based on this data, we developed performance evaluation program of BIPV system named BIPV-Pro, through multiple regression analysis and evaluated its validity. Result: When comparing predictive value of annual average PR and annual electricity production of BIPV-Pro an that of PVsyst, each of root mean square error was 0.01897 and 123.9.

The verification about possibility of introducing Window to Floor Ratio as design index for building energy performance

  • Choi, Won-Ki;Lee, Yong-Jun;Lee, Hyun-Soo;Eom, Jae-Yong;Lee, Chung-Kook
    • KIEAE Journal
    • /
    • v.17 no.1
    • /
    • pp.23-28
    • /
    • 2017
  • Purpose: Many design index that are using in planning phase have been developed. The most popular things among them are Window to Wall Ratio and Surface to Volume Ratio. However there are some limits. Window to Wall Ratio cannot consider building size and Surface to Volume Ratio cannot do Window to Wall Ratio. Accordingly, in this paper, the Window to Floor Ratio was proposed that it can be considered both building size and Window to Wall Ratio. And analyzed correlation of energy demand. Method: For the test, 16 modules with the size of $6m{\times}6m{\times}4m$ were used to make 35 models with the same volume. The simulation was conducted to 945 cases using the window-to-wall ratio of 30, 50 and 70 % in three areas such as Seoul, Gwangju and Jeju and three kinds of windows. And IES_VE was used. Result: The findings above show that the Window to Floor Ratio that can be considered both building size and Window area have to become as design index. It was found out that design criteria with SHGC is necessary, not with the thermal performance (U-value). It is needed to additional analysis about residential building and the effect of 24-hours heating and cooling condition. It plans to carry out research to establish design indicators for climatic conditions in the country and building applications.

Analyzing Home Network System Adaptation Status in Apartments (아파트 홈네트워크 시스템 적용실태 조사연구)

  • Lee Sun-A;Chang Kyung-Moon;Kim Jae-Jun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
    • /
    • 2004.11a
    • /
    • pp.571-574
    • /
    • 2004
  • It is rapidly expanding to provide Home Digital Service based on the Home Network System in intelligent apartment. Fortunately, Korea has one of the highest rates of Internet penetration and access in the world. Construction companies used the Home Network system as a strategy of differentiation and it is available to the customers to raise their asset value. Besides, the government has a positive response to accept the new movements to make the digital environment with 'u-Korea (Ubiquitous Korea)' as the slogan. However, the level of providing Home Digital Service is actually at the beginning. The develop the home network industry more effectively, the related industries' cooperation is essential. The purpose of this study is to propose a providing model of Home Network System for the construction company and to make a method to response the fast change of technology development and customer's request at the point of construction companies' view.

  • PDF

A Historical Analysis on the Limitation of Carriers' Liability (운송인(運送人)의 손해배상책임제한(損害賠償責任制限)에 관한 역사적(歷史的) 고찰(考察))

  • Oh, Soo-Geun
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.5
    • /
    • pp.171-205
    • /
    • 1993
  • On the contrary to the general principle of private law, carriers' liability for passengers and cargo owners have been quantatively limited in some cases. The author traces the rule of liability limitation in the law of Korea and United States to verify two hypotheses. The first hypothesis is that the rule of liability limitation has been introduced to motivate investment when new technology with high risk has been adopted in business. The second hypothesis is that the rule of liability limitation can be maintained only when damages have been fully compensated. The former is a necessary condition for liability limation, and the latter sufficient condition. There are strong evidences for the first hypothesis. Navigation or aviation, artificial satellite lauching, urban transportation system are good examples. The second hypothesis is supported by the fact that there have been continuous controversies on the Warsaw System, including the failure of ratification of Montreal Additional Protocols No.3 & 4 by the U.S. Senate and voluntary removal of liability limitation by the Japanese airline companies. Loss of cargo can be compensated fully, but damages from personal injury and death not. The value of human body and life is not easy to be estimated. Passengers, moreover, do not usually buy insurance for accidents in travel. Passengers do not accept insurance premium as the cost of being whole and alive. They do not accept accident rates realistically. They have no bargaining power in dealing with insurers. The rule of liability limitation in personal losses would not be supported in future because damages have not fully compensated.

  • PDF

Design of a Low Power Consumption Accumulator for Parallel Correlators in Spread Spectrum Systems (대역확산 시스템용 병렬 상관기를 위한 저 전력 누적기 설계)

  • Ryoo, Keun-Jang;Chong, Jong-Wha
    • Journal of the Korean Institute of Telematics and Electronics C
    • /
    • v.36C no.12
    • /
    • pp.27-35
    • /
    • 1999
  • In a typical spread spectrum system, parallel correlator occupies a large fraction of power consumption because of the large number of accumulators in the system. In this paper, a novel accumulator is proposed that can reduce the power consumption in the parallel correlator. The proposed accumulator counts the numbers of 1 of the incoming input data. The counted values are weighted and added together to obtain the final correlation value only at the end of the accumulation. The proposed accumulator has been designed and simulated by CADENCE Verilog-XL and synthesized by SYNOPSYS Design Compiler with $0.6{\mu}m$ standard cell library. Power consumption results have been obtained from EPIC PowerMill simulations. Simulation results are very encouraging. First, the power dissipation is reduced by 22% and the maximum operating frequency is increased by 323%. In addition, the parallel correlator using the proposed accumulators consumed less power than the conventional active parallel correlators by 22%, and less power than the conventional passive correlator by 43%.

  • PDF

The effects of dentin bonding agent formulas on their polymerization quality, and together with tooth tissues on their microleakage and shear bond strength: an explorative 3-step experiment

  • Erfan, Mohmmad;Jafarzadeh-Kashi, Tahereh Sadat;Ghadiri, Malihe;Rakhshan, Vahid
    • The Journal of Advanced Prosthodontics
    • /
    • v.6 no.5
    • /
    • pp.333-345
    • /
    • 2014
  • PURPOSE. Bonding agents (BA) are the crucial weak link of composite restorations. Since the commercial materials' compositions are not disclosed, studies to formulize the optimum ratios of different components are of value. The aim of this study was to find a proper formula of BAs. MATERIALS AND METHODS. This explorative experimental in vitro study was composed of 4 different sets of extensive experiments. A commercial BA and 7 experimental formulas were compared in terms of degree of conversion (5 experimental formulas), shear bond strength, mode of failure, and microleakage (3 experimental formulas). Statistical analyses were performed (${\alpha}$=.05). The DC of selected formula was tested one year later. RESULTS. The two-way ANOVA indicated a significant difference between the shear bond strength (SBS) of two tissues (dentin vs. enamel, P=.0001) in a way that dentinal bonds were weaker. However, there was no difference between the four materials (P=.283). The adhesive mode of failure was predominant in all groups. No differences between the microleakage of the four materials at occlusal (P=.788) or gingival (P=.508) sites were detected (Kruskal-Wallis). The Mann-Whitney U test showed a significant difference between the microleakage of all materials (3 experimental formulas and a commercial material) together at the occlusal site versus the gingival site (P=.041). CONCLUSION. A formula with 62% bisphenol A-glycidyl methacrylate (Bis-GMA), 37% hydroxy ethyl methacrylate (HEMA), 0.3% camphorquinone (CQ), and 0.7% dimethyl-para-toluidine (DMPT) seems a proper formula for mass production. The microleakage and SBS might be respectively higher and lower on dentin compared to enamel.

Evaluation of the reproducibility of various abutments using a blue light model scanner

  • Kim, Dong-Yeon;Lee, Kyung-Eun;Jeon, Jin-Hun;Kim, Ji-Hwan;Kim, Woong-Chul
    • The Journal of Advanced Prosthodontics
    • /
    • v.10 no.4
    • /
    • pp.328-334
    • /
    • 2018
  • PURPOSE. To evaluate the reproducibility of scan-based abutments using a blue light model scanner. MATERIALS AND METHODS. A wax cast abutment die was fabricated, and a silicone impression was prepared using a silicone material. Nine study dies were constructed using the prepared duplicable silicone, and the first was used as a reference. These dies were classified into three groups and scanned using a blue light model scanner. The first three-dimensional (3D) data set was obtained by scanning eight dies separately in the first group. The second 3D data set was acquired when four dies were placed together in the scanner and scanned twice in the second group. Finally, the third 3D data set was obtained when eight dies were placed together in the scanner and scanned once. These data were then used to define the data value using third-dimension software. All the data were then analyzed using the non-parametric Kruskal-Wallis H test (${\alpha}=.05$) and the post-hoc Mann-Whitney U-test with Bonferroni's correction (${\alpha}=.017$). RESULTS. The means and standard deviations of the eight dies together were larger than those of the four dies together and of the individual die. Moreover, significant differences were observed among the three groups (P<.05). CONCLUSION. With larger numbers of abutments scanned together, the scan becomes more inaccurate and loses reproducibility. Therefore, scans of smaller numbers of abutments are recommended to ensure better results.

The Application of Jean Michel Basquiat's Graffiti to Fashion Painting (Jean Michel Basquiat의 그래피티(Graffiti)를 응용한 패션페인팅)

  • Jang, Ae-Ran;Ko, Eun-Suk
    • Journal of the Korean Home Economics Association
    • /
    • v.44 no.6 s.220
    • /
    • pp.23-34
    • /
    • 2006
  • Graffiti has been recognized as an art form since the influence of free, black culture and Neo-Expressionism in the 1980s, though Graffiti remains the subject of controversy both inside and outside the school Modem Art. Jean Michel Basquiat is the most famous Graffiti artist of the '80. He was regarded as the genius and star of American art, leaving a lot of experimental and creative works during his short, 9-year, creative period. In his works, Basquiat well expressed the isolated and dark shadows in the U.S., the pursuit of self identification, the purpose of expression and the epochally social phenomenon. The purpose of this study is to investigate the application of Jean Michel Basquiat's Graffiti to fashion painting. To achieve this purpose, we present a lot of fashion painting works which apply Jean Michel Basquiat's Graffiti by focusing on autographic experience, racialism, cartoon themes, monely value, and anatomical death in the characteristics of Basquiat's works. Through this process, we can express and apply Basquiat's Graffiti to fashion painting by analogizing the themes and modeling the methods of his works, such as childish and simple features, intentionally wrong spellings and sentences, and symbols of death including skeletons, intestines, bones and teeth. In addition, Basquiat's techniques are examined in this study, including the representational handling of a brush, primitive and strong colors, and maximized shape. This study found that fashion painting can juxtaposes art and fashion by expressing Jean Michel Basquiats' Graffiti.

CHARACTERISTICS OF THE FAIRCHILD 486 CCD AT MAIDANAK ASTRONOMICAL OBSERVATORY IN UZBEKISTAN (우즈베키스탄 Maidanak 천문대 Fairchild 486 CCD의 기본적인 특성)

  • Lim, Beom-Du;Sung, Hwan-Kyung;Karimov, R.;Ibrahimov, M.
    • Publications of The Korean Astronomical Society
    • /
    • v.23 no.1
    • /
    • pp.1-12
    • /
    • 2008
  • Understanding of the basic characteristics of an astronomical instrument is a prerequisite to obtaining reliable data from the instrument. We have analyzed more than 1,000 calibration images from the Fairchild 486 CCD (hereafter the Maidanak 4k CCD system) attached to the AZT-22 1.5m telescope at Maidanak Astronomical Observatory in Uzbekistan. The Maidanak 4k CCD system supports three readout modes through 1, 2, or 4 amplifiers. In most cases observers use 4-amplifier readout mode to save time. We have tested the stability and seasonal variation of zero levels and confirm that two quadrants of the images (Amp 1 & 2) show no appreciable seasonal variation. but the other two quadrants (Amp 3 & Amp 4) show an evident seasonal variation in the bias level. The Cryo Tiger, the cooling system used at the Maidanak 4k CCD system, maintains the CCD temperature at -108'E, and effectively suppresses the dark electrons. The mean value versus the variance plot of the flat images does not show the expected relation for an ideal Poisson noise distribution and this is attributed to the large variation in quantum efficiency between different pixels. In addition, we confirm that there is no appreciable difference in gain between readout amplifiers, but there is a large variation in quantum efficiency across CCD chip especially in U. Due to the finite length of shutter opening and closing time, the effective exposure time varies across the science images. We introduce two parameters to quantify the effect of this uneven illumination and present a method to remove these effects. We also present a method to remove the interference patterns appearing in the images obtained with longer wavelength filters and investigate the spatial variation of the point spread function.