• International Journal of Highway Engineering
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• v.10 no.1
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• pp.75-85
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• 2008

Moisture damage of asphalt mixtures can occur because of a loss of bond between the asphalt binder and the fine and coarse aggregates. Therefore, moisture damage on asphalt pavements is the main cause of potholes, which is one of the main distress type of asphalt pavement. The purpose of this study is to evaluation effect moisture damage on material properties of asphalt mixtures through the laboratory performance test. The existing Modified Lottman test procedure was improved and the number of times that thermal cyclic conditioning can be added until the asphalt mixtures is damaged, was tested in order to exhibit the changes of the material properties because of moisture damage by immersion. Through the above experiments, it was found that the material properties of asphalt mixtures on room-temperature were rapidly decreased with loss of about 50% at initial stage of moisture damage caused by the amount of repeated immersion. Also, it was found that the property damage ratio using material properties of failure energy and $DCSE_f$ by test temperature $25^{\circ}C$ were showed a high relationship to moisture damage of the asphalt mixtures caused by the amount of repeated immersion.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.29-36
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• 2008

The shotcrete is a NATM technique as a major tunnel support for ground stability after tunnel excavation. Instead of a general concrete lining method, it is a trend for curtail of construction periods and reduction of construction expenses that required to use of the permanent shotcrete lining. This high-strength shotcrete is required to use as a permanent shotcrete lining. This brought out the solution of environmental pollution and harmfulness to human. Accordingly, in this study specimens for strength measurement were made to develop shotcrete possible to develop materials in early with cement mineral accelerator as NATM method construction. It was compared with existing shotcrete material, unconfined compression test, flexural strength test, antiwashout underwater test were experimented. The fish poison test was experimented to evaluate an influence of environment. As a results of the test, unconfined compressive strength and flexural strength were equivalent with 28-curing day strength of existing material. An antiwashout of research subject material was revealed excellently in antiwashout Underwater test. As a results of the fish poison, an evaluation research subject material was founded more environmentally friendly than existing shotcrete.

• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.85-97
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• 1999

For a deltaic clay in the mouth of the Nakdong river, OCR was investigated through methods using the results of field measurement, laboratory and field soil tests. As a result, OCRs were obtained around the range of 0.95 to 1.20 by analysis of field measurements, although they were estimated around the values of 0.4 to 0.7 by the results of conventional consolidation tests for the clay. From the dissipation test it was found out that the excess pore pressures scarcely existed in the clay deposit and then the soil was not in the underconsolidated condition. And the OCRs obtained through methods of Mayne(1991) and Cao et al(1996) using the piezocone test and of Mayne & Kemper(1988) using the cone penetration test were in good agreement with those of field measurement.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.05a
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• pp.73-82
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• 2003

본 연구에서는 국내 종계의 생산성 저하요인들을 평가·분석하였으며, 국내사육 종계의 실질적인 생산성을 극대화 시킬 수 있는 방안을 제시하고자 시험을 수행하여 다음과 같은 결론을 얻었다. 1. 혈청검색에 의한 품종별 종게군 질병 모니터링을 실시 한 결과, SE, MS 등 2종의 난계대성 세균성 질병과 REV, APV, CAV, ORT, REO 등 5종의 만성소모성 질병을 유발하는 질병이 종계군의 산란기에 감염되어 이들이 단독 또는 중복감염되어 나타나는 피해가 예상되었으며, 이들의 감염을 효과적으로 예방 할 수 있는 백신의 개발 및 도입의 필요성이 대두되었다. 2. 집중관리 모니터링 대상농장에 대한 ND, IB, IBD 등 3종의 생독백신에 대한 접종효능을 평가해 본 결과 산란종계, 육용종계를 막론하고 전반적으로 니플급수기를 이용한 음수접종법 적용시 5주령 이하 계군에 2내지 3회의 음수접종을 실시하였음에도 불구하고 항체가 거의 형성되지 못하거나 매우 불균일한 면역반응이 나타나는 것으로 조사되어 국내 야외농장에 대한 분무접종 유도 등 기존의 백신접종법에 대한 시급한 개선대책 마련이 요구되었다. 3. 육성기 및 산란기 종계 질병·위생관리 프로그램 확립을 위하여 ND, IB, IBD에 대한 개선된 백신접종 프로그램을 모델계군에 적용한 후, 주령별로 생독백신 접종효능을 조사한 결과 백신접종 후 ND, IB, IBD에 대한 평균 항체가와 항체의 균일도 (%CV)가 표준 목표치 이상 상승하여 개선의 효과를 볼 수 있었다. 4. 산란기 종계 질병·위생관리 프로그램 확립을 위하여 실시된 변이형 IB에 대한 방어능 시험결과 정기적인 Mass type IB 생독백신의 분무접종은 국내 유행 호흡기형 IBV 유전형 VI에 대한 방어효과는 다소 떨어지는 것으로 조사되어 국내분리주를 이용한 IB 생독백신의 개발이 요구되었다. 5. 종계장 살모넬라 및 마이코플라즈마 조기 검출을 위하여 실시한 종계장 살모넬라 및 마이코플라즈마 환경 모니터링 실시 결과 기존의 평판응집반응이나 ELISA에 의한 혈청검색법에 비하여 검출효율이 매우 높은 것으로 조사되어 향후 국내 종게군에 대한 살모넬라 및 마이코플라즈마 조기검출과 방제연구에 큰 도움이 될 것으로 사료되었다.

• International Journal of Highway Engineering
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• v.4 no.3 s.13
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• pp.43-49
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• 2002

Asphalt pavements have to perform under the conditions of heavily-loaded vehicles due to the industrialization and large temperature variance between the summer and the winter. Due to these factors, a characteristics change of early permanent deformation becomes a big issue, and to remedy this problem many research to use modified asphalt are being widely conducted. However, most of the modified asphalt is being paved after milling the surface course and applying tackcoating, and it is being used mostly for the repair and maintenance purpose rather than pavement of new national road. The purpose of this investigation is to obtain some fundamental data for the evaluation of the performance and long-term performance of the construction material mixtures by the laboratory test and field experiments. For the field experiment, 200m of two-lanes national road, that is being paved for the new national road under the direction of Pusan Regional Construction Management Office, was paved with SBS PMA and PSMA asphalt mixtures, which are an modified asphalt mixtures used for the surface course, on top of the base course paved with other modified asphalt mixtures. The remaining section of the new national road was paved with dense grade mixture. The laboratory tests assessed and analyzed the mixture characteristics by Marshall's stability test, strength tests and wheel-tracking test. On the basis of the evaluation result of the temperature control and roughness of the newly constructed road at the field experiment site, it is desired to evaluate and identify the most economic modified asphalt mixtures by long-term performance evaluation and LCC(Life Cycle Cost) analysis in order to apply the test result to the design of new road construction in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.468-474
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• 2017

A test service for the weapon systems evaluation is one of the most important processes during the weapon systems acquisition or development life cycle. Before completion of weapon systems development, the appropriate evaluation test can reduce risk and expense which might be expected during weapon systems development procedure. In this paper, it is suggested that a probabilistic prediction method based on Monte Carlo simulation for how much the annual weapon systems evaluation test excution ratio can be reached compared to the yearly initial planned test quantity. And then a weapon systems evaluation test quantitative management scheme is suggested to assist decision making for the test schedule manager who can arrange monthly test schedule based on the prediction result of annual test excution ratio. And the proposed method is applied for the weapon systems evaluation firing test data of the 8th directorate, Agency for Defense Development(ADD). And also the application result is examined.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.5
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• pp.78-86
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• 2014

The purpose of this study is the displacement and velocity dependence evaluation of I type and S type metallic dampers. For this purpose, 12 metallic damper specimens are prepared and dependence test are performed. Test variables are strut type, displacement and velocity dependence. From the evaluation results of dependence tests, number of cycles are fully exceeded than minimum 5 cycles described in ASCE 7-10. According to displacement dependence test results, larger target displacement (50mm) shows lower cyclic numbers and cumulated energy dissipated area than lower target displacement (25mm). Also it show higher strength and early failure than short target displacement. In velocity dependence evaluation, fast target velocity (60mm/sec) shows lower cyclic numbers and cumulated energy dissipated area than target velocity (40mm/sec). As a results of basic properties, dependence evaluation and cumulated energy dissipated area evaluation, dependence capacity of S type metallic damper is far superior than I type.

• Journal of the Korea Concrete Institute
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• v.14 no.5
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• pp.774-781
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• 2002

Shear behaviors of eight dapped ends of four full-scale domestic single-tee slabs were evaluated. The dapped ends with 10cm topping concrete were designed based on live load requirements for the domestic parking lot of m 500kgf/㎡ and for the large market of 1,200 kgf/㎡. All specimens were designed by the ACI 318-99 design. The variations of the experiment were the shape of hanger reinforcements as followings: 1) general PCI design method(currently used in domestic), 2) 90 degree bent-up, 3) 60 degree bent-up. All experiments were conducted with 1.2 m shear span. The results obtained in this study were 1) all specimens fully complied with the shear strength requirements as specified by ACI 318-99 except for one strand bond slip specimen, 2)a specimen with the 60 degree bent up hanger reinforcing detail showed the best shear behaviors under full service and ultimate load, and 3)a specimen with the 90 degree bent up hanger reinforcing detail resulted in the worst shear behaviors.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.59-67
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• 2012

This study presents the evaluation of the patching materials that are used to repair the distress of asphalt pavement. Four kinds of patching materials currently used in practice were tested in both laboratory and field. The laboratory tests included the dry and soaked Marshall stability test, indirect tensile test, wheel tracking test and adhesive strength between the asphalt pavement and the repairing material was tested as a performance test. The field study was conducted using the slab samples placed on the location of vehicle tire passing and the performance of the repairing materials were investigated as passing the traffic load. The result of the laboratory tests were satisfied with the current design criteria and material standard except for water-immersion stability. Type C patching material showed the highest adhesive shear strength among the patching materials tested. However, the mature distress, such as rutting and stripping were monitored after construction in 10 days. It was found that performance of patching material is lack of quality behavior when they were applied in the field and required to develop and applu to prevent the mature distress of the current patching materials.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.124-131
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• 2016

The toxic responses of flagellate Euglena agilis Carter to 8 heavy metals (Ag, Cd, Cr (VI), Cu, Hg, Ni, Pb, Zn) were measured using E. agilis system (E-Tox), an automated biomonitoring system. The E-Tox measures cell movement parameters, such as velocity, motility, and forms of the cells, as biological endpoints. $EC_{50}$ values from the E. agilis biomonitoring test were compared with the literature data from the tests with Daphnia magna, Vibrio fischeri and Euglena gracilis. Measurement of the E. agilis movement behavior and D. magna acute toxicity test were also conducted for the wastewater samples. E. agilis is less sensitive than D. magna but is comparable to or more sensitive than V. fischeri and E. gracilis for the heavy metals tested in this study. E. agilis shows prompt changes of these parameters for the toxic metal plating wastewater. Major advantages of the E-tox are automatic, easy to handle and fast ecotoxicity monitoring system compared to other biological test systems. These results imply that E. agilis biomonitoring test using E-Tox can be a putative ecotoxicity test as a good early warning tool for the monitoring of toxic wastewater.