• Title/Summary/Keyword: earth-work

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Antitank Mine Detection with Geophysical Prospecting (물리탐사를 이용한 대전차 지뢰 탐지)

  • Cho, Seong-Jun;Kim, Jung-ho;Son, Jeong-Sul;Bang, Eun-Seok;Kim, Jong-Wook
    • 한국지구물리탐사학회:학술대회논문집
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    • 2007.06a
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    • pp.219-224
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    • 2007
  • We conducted geophysical surveys to detect antitank mine at Namji-eup, Gyeongsangnam-do which had been installed during Korean war. The surveys consisted of 2 stages, at the first stage we divided the survey area into 7 block and carried out magnetic gradient survey and GEM-3 EM survey sequentially for each block. Hence we verified anomaly areas using an excavator and a metal detector. Most of anomalies were found to be garbages such as trash cans, metallic wastes, and so on. And also, the concrete pipe was found at depth of 1 m, which had not referred in any report of that area. At the second stage, after trenching the covered soil down to 75 cm the same surveys were conducted. We could not find the strong signal to be inferred from a antitank mine, but we pointed out some anomalies to need careful handling because demining is very dangerous work even though there is few possibility that is mine.

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A Study on Trend of the DDA Environmental Negotiation and Measures to Settle Environmental Dispute (DDA(Doha Development Agenda) 환경협상동향과 환경분쟁 예방 방안)

  • Jo Seok-Hong
    • Journal of Arbitration Studies
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    • v.14 no.1
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    • pp.185-211
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    • 2004
  • It is a common and prevailing Construction that recent environmental problems such as earth's warmer climate and depletion of ozone layers can never be solved by the efforts of any one nation. That is why the international conventions have been held more often lately in order to discuss the matter of environment protection and there has been increased tendency of using economic activities of any nation especially their international trades as means for achieving the purpose of environment protection. Furthermore, there is an ample possibility for the advanced countries to use the regulatory restrictions for environment protection as an another measure of none-tariff barrier against countries including Korea which has high dependence on international trade with not very high technological capability of environment protection. Some of the developed countries have recently moved toward the creation of a new system of international regulatory measures on world trade in the name of Environment Protection. They Plan to impose strict control over the process and technology of production of good they are importing from other country. However, ever though the international regulatory measures, in a short term, could play a negative role on our trade capability, they could, in the long run, also play a role of helping hands if we usefully work out positive countermeasures as a result of hand-working government supported by industry and all the society as a whole.

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A Study on the Cognition of Structure and Contents of Elementary 3rd and 4th Grade Science Textbook in the 7th curriculum (제7차 교육과정에 따른 초등학교 3, 4학년 과학 교과서의 체제와 내용에 대한 인식 조사)

  • 김정애;노석구
    • Journal of Korean Elementary Science Education
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    • v.22 no.1
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    • pp.37-50
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    • 2003
  • The purpose of this study was to develop the quality of the textbook and to find out reasonable selection and structure by examining and analyzing the cognition of teacher and students on the structure and contents of elementary science textbook in the 7th curriculum. The findings of this study were as follows: First, as a result of the students’ cognition, their interest level of the learning contents was high and the degree of the difficulty of the learning contents was low on the whole. Second, as a result of the teachers’ cognition of contents of the textbook, teachers who taught third graders understood that the third graders have relatively much contents to be studied and the level of the contents of the textbook was high. On the other hand, fourth graders’ teachers recognized that contents to be studied and the level of the contents were appropriate. And they understood that there were much work to be studied in the units which were difficult and there were difference between contents to be studied and the degree of the difficulty in some units such as life or the earth fold. Third, as a result of the teachers' cognition of structure of the textbook. teachers were very affirmative to reduce school hours. They understood that current numbers and scale of the unit were appropriate. Teachers were satisfied with the structure of elementary science textbook in the 7th curriculum on the whole.

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The Effect of Fusible Interlining on the Appearance related Properties & Mechanical Characteristics of the Lyocell Fabrics(II) (리오셀직물의 심지접착에 따른 외관적 성능 및 역학적 특성(II))

  • 김인영;오수민;송화순
    • Journal of the Korean Home Economics Association
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    • v.40 no.7
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    • pp.15-24
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    • 2002
  • In this work, the effect of fusible interlining on the appearance related properties and mechanical characteristics of Lyocell fabric after fusing was investigated. Two different types(20's and 10's) of Lyocell face fabric with six different interlining(by thickness and structure) for earth Lyocell fabric were examined. In order to establish the optimum fusing condition for the different face fabric and interlining, peel strength of each fused fabric was measured, which was dependent on the fusing temperature, pressure, and time. The characteristics related appearance and mechanical characteristics of each fused fabric were determined. The results are as follows: The peel strength was excellent, when the fabric was fused with the force of 3kgf/$textrm{cm}^2$ at $120^{\circ}C$ for 15seconds. Flex stiffness, G, 2HG, 2HG5(shear), B, 2HB(bending) of 100% Lyocell fabric 10's were higher than those of 100% Lyocell 20's. Flex stiffness, crease recovery, G, 2HG, B, 2HB of thicker woven interlining were higher than those of thinner woven interlining. Crease recovery of twill interlining were higher than those of plain interlining. In case of shear and bending properties, however, plain interlining was higher than twill interlining. Flex stiffness, crease recovery, G, 2HG, 2HG5, B, 2HB of nonwoven interlining were higher than those of woven interlining. In case of drapability, however, woven interlining was higher than nonwoven interlining.

A Study of CFRD using a Gravel Fill (하상사력재를 이용한 CFRD의 연구)

  • Jeong, Chan-Kyun;Noh, Tae-Gil;Lee, Song
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.842-853
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    • 2008
  • In the construction of dam, the key factor which decides the type of dam is security of materials resource. Because of the large scale earth work, the ability to supply the materials is essential part about economical efficiency. The research is the case study about controlling the plan to secure the material resources in the design of Buhang multipurpose dam. In case of Buhang multipurpose dam, at that time of basic design, it was planned to use a rock fill material. From the detail investigation about the river bed accumulative layer widely spread on the submerged district on the basic design, the research is accomplished to replace rock material with gravel material. After the investigation of whole reserves of gravel material, estimation of conformity as dam construction material from analysis of grain size distribution, the case study of oversea construction, and the material property comparison between rock fill material and gravel fill material, it is verified th possibility of using the gravel fill. Thereafter, the analysis of dam stability using a gravel fill material is accomplished. Finally, A gravel fill material can be used as the main construction material of CFRD, therefore the efficiency of resource recycling in the submerged area is maximized, and the established plan is more advantageous to stability, constructibility, environmentibility than the case of using a rock fill.

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A Case Study for Deformation of Caisson caused by Friction Shortage (케이슨 하부의 마찰저항 부족에 따른 케이슨 안벽 변위발생 사례연구)

  • Shim, Dong-Hyun;Park, Jun-Ho;Lee, Kyung-Sook
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.325-336
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    • 2008
  • Deformation of caisson occurred during the backfilling behind the caisson and some caisson moved toward seaside. A series of site investigation were conducted to figure out various circumstances at site and also used to analyze the cause of deformation. The soil condition of backfilling is also investigated because dredged material was used as a backfill material. The friction angle of backfill is supposed to be lower than the estimated one which was used in design stage. To determine the cause of friction shortage, back analysis for sliding safety were carried out with considering the soil condition of backfilling. A remedial plan, re-rising and relocating a caisson with backfilling good earth after treatment of caisson rubble mound to achieve the safety for sliding was proposed as a best solution based on the back analysis results. Reform concrete structure including service gallery and crane rail was also considered with the remedial work to improve the cape line of caisson.

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Characteristics of Location Accuracy in KOMPSAT-2 (다목적실용위성2호 위치정확도 특성)

  • Seo, Doo-Chun;Park, Ji-Yong;Choi, Hea-Sun;Jung, Jae-Heon;Hong, Ki-Byung;Lee, Sun-Gu
    • Aerospace Engineering and Technology
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    • v.12 no.1
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    • pp.144-151
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    • 2013
  • The KOrea Multi-Purpose SATellite-2 (KOMPSAT-2) is to provide 1.0 m Ground Sample Distance (GSD) panchromatic image and 4.0 m GSD multi-spectral image data for various applications. The KOMPSAT-2 system performs mission applications in the field of earth observations, covering land, sea, coastal zones, and Geographic Information Systems (GIS). The purpose of this document is to compute ground coordinate using satellite position, velocity and attitude data in KOMPSAT-2 and document for work-flow of location accuracy correction in KOMPSAT-2.

Fashion Design Study by Whole Cut Way (Whole cut에 의한 패션디자인 연구)

  • Park, You Shin
    • Journal of Fashion Business
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    • v.19 no.5
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    • pp.199-212
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    • 2015
  • Environmentally-friendly whole-cut designs can minimize carbon dioxide emissions which are harmful to the earth, and reduce energy, labor force and time in cutting or sewing clothes. The design and way of wearing clothing will be investigated by classifying whole-cut clothing appearing in the history of costume and past traditional outfits such as Drapery, a Pancho, Tunic, or Loincloth. According to the results from the analysis of whole-cut methods applied in design, they were classified as follows: whole-cut, utilizing square-panels as is, pleats, smoking, lip band, origami, cutting way, and subtraction-cutting whole-cut design. The whole-cut design utilizing square panel as it is can minimize the waste of energy and material but can also maximize the possibility of circulation by recycling. In utilizing an all square panel, it broke away from the existing whole-cut in the western pattern, namely, the pattern of clothes clinging to the body, and was found to have new aesthetic value with a new approach. Due to the whole-cut method having a restriction in the use of dart and line cutting in its designing process, there were only designs that did not show the body line, such as designs clinging to the body. Therefore we developed a design similar to those that cling to the body by whole-cut, In addition, the work produced was with high efficiency and variability, which produces simple designs but can be worn in a variety of ways.

Preliminary Design of Power Control and Distribution Unit for LEO Application (저궤도 위성 응용을 위한 전력조절분배기 설계)

  • Park, Sung-Woo;Park, Hee-Sung;Jang, Jin-Baek;Jang, Sung-Soo;Lee, Sang-Kon
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.55-57
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    • 2007
  • A Power control and Distribution Unit (PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU for the small Low Earth Orbit (LEO) Satellite applications. The main constitutes of the PCDU are the battery interface module, solar array regulators with maximum power point tracking (MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation, power distribution modules of unregulated and regulated primary bus, and instrument power distribution modules.

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Aspect Ratio Behavior of Grinding Particles with Variation of Particle Size by Wet Grinding (습식분쇄에 의한 입자크기 변화에 따른 분쇄입자의 종횡비 거동)

  • Choi, Jin Sam
    • Korean Journal of Materials Research
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    • v.30 no.5
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    • pp.223-230
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    • 2020
  • As a case study on aspect ratio behavior, Kaolin, zeolite, TiO2, pozzolan and diatomaceous earth minerals are investigated using wet milling with 0.3 mm media. The grinding process using small media of 0.3 pai is suitable for current work processing applications. Primary particles with average particle size distribution D50, ~6 ㎛ are shifted to submicron size, D50 ~0.6 ㎛ after grinding. Grinding of particles is characterized by various size parameters such as sphericity as geometric shape, equivalent diameter, and average particle size distribution. Herein, we systematically provide an overview of factors affecting the primary particle size reduction. Energy consumption for grinding is determined using classical grinding laws, including Rittinger's and Kick's laws. Submicron size is obtained at maximum frictional shear stress. Alterations in properties of wettability, heat resistance, thermal conductivity, and adhesion increase with increasing particle surface area. In the comparison of the aspect ratio of the submicron powder, the air heat conductivity and the total heat release amount increase 68 % and 2 times, respectively.