• Journal of the Korean Geotechnical Society
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• v.31 no.5
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• pp.23-33
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• 2015

In the present study, a ground heat exchanger was installed for each heat source in the system at the site to evaluate ground heat conductivity, constructability, and economic feasibility; the factors considered in the study included ground heat, groundwater, fillers (such as bentonite and pea pebbles) and the shape of the heat exchange pipe (e.g., U and D-U). The aim was to determine the ground heat exchanger appropriate for the geothermal system in the 3rd-phase construction of Incheon International Airport. A comparative cost analysis of the initial costs based on the above information showed that although the initial costs of the regular vertical closed loop-II and modified vertical closed loop were lower than those of the regular vertical closed loop-I, they could not be expected to deliver high economic efficiency from the viewpoint of constructability (filler injection, heat exchange pipe insertion). The initial costs proved to be higher in the case of Geohil.

• Journal of the Korean Geotechnical Society
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• v.28 no.10
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• pp.41-54
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• 2012

This paper is to develop the method of surface soil improvement by electric heating equipment. For this purpose, the electric heating systems were invented to apply to the in-situ soil. Iaboratory tests were done to study the behaviors of sea clays by eletric heating. In lab tests, two different heating temperatures, $70^{\circ}C$ and $110^{\circ}C$, were applied to the saturated clays to examine the relationship between evaporation and compaction. In addition, trafficability was analyzed to the heated by applying cone penetrometer to the heated clays Furthermore, in-situ tests were conducted to analyze the range of soil improvement and strength variations. The temperature changes in field were measured and they were compared with those of the commercial program (Temp/W). Also, the bearing capacities of electrically heated field were tested by PBT (plate bearing test). Several conclusions were derived from the results of the numerical analysis and tests (lab and field). The improvement ranges and strength variations of electrically heated soil depended on the heating temperature and time. If the heating temperature is more than $100^{\circ}C$ evaporating the ground water, the bearing capacity and settlement increased rapidly. The bearing capacities of in-situ soil increased more than 3 times, and heated soil emitted a lot of vapors. The soil around electric heater was sintered completely, and its range was almost 20 cm.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.196-200
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• 2006

In this study we investigated fecundity and survivorship of four staple Korean freshwater cladocerans for their whole life to develop a new standard method used for ecological risk assessment of pesticide. The tested Korean freshwater cladocerans were Daphnia obtusa, Daphnia sp., Moina macrocopa and Simocephalus vetulus. In addition, standard test species, Daphnia magna endorsed formally by the major international organizations was tested together in order to compare with the reproductive characteristics of Korean cladocerans. A total of 358 young was produced by D. magna, whereas, 297 young was reduced by Daphnia sp. throughout the entire life. The average life span of Daphnia magna was 50 days much longer than any other Korean species. Nevertheless all of the Korean water flea tested showed good fecundity, produced over 60 young for 21 days as the validation criterion for reproduction toxicity test in Ecological Effects Test Guidelines published by USEPA. Especially Moina macrocopa produced their first brood in 4 days. Therefore 10 day reproduction test with Moina macrocopa may be an alternative good method to save cost and time to elucidating the effects of hazardous substances on the reproduction of aquatic invertebrates.

• Asian Journal of Turfgrass Science
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• v.24 no.1
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• pp.56-61
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• 2010

This study was conducted to evaluate the effect of application of SCB liquid fertilizer produced after slurry composting and biofiltration (SCB) on turfgrass growth in golf course during 6 month period from May to October in 2008. The change of soil properties by applying CF and SCB was unaffected respective treatments. As compared with NF, turf color index of CF, S-1 and S-2 increased by 1.8%, 2.5%, and 3.4%, respectively and chlorophyll content by 13%, 19%, and 25%, respectively. Dry weight of S-1 and S-2 was increased by 15% and 26% than that of CF. As compared with CF, N uptake rate in S-1 and S-2 was increased by 21% and 37%, P uptake rate 57% and 28%, and K uptake rate 16% and 27%, respectively. S-2 showed the best effect for turf color index, chlorophyll content, dry weigh and nutrient uptake rate in creeping bentgrass. These results suggested that an mixed application of SCB and compound fertilizer was improved turf quality and growth of creeping bentgrass by increasing nutrient uptake rate of turfgrass.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.298-305
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• 2017

Benzovindiflupyr is a new pyrazole carboxamide fungicide that inhibits succinate dehydrogenase of mitochondrial respiratory chain. This study was carried out to develop an analytical method for the determination of benzovindiflupyr residues in agricultural commodities using LC-MS/MS. The benzovindiflupyr residues in samples were extracted by using acetonitrile, partitioned with dichloromethane, and then purified with silica solid phase extraction (SPE) cartridge. Correlation coefficient ($r^2$) of benzovindiflupyr standard solution was 0.99 over the calibration ranges ($0.001{\sim}0.5{\mu}g/mL$). Recovery tests were conducted on 5 representative agricultural commodities (mandarin, green pepper, potato, soybean, and hulled rice) to validate the analytical method. The recoveries ranged from 79.3% to 110.0% and then relative standard deviation (RSD) was less than 9.1%. Also the limit of detection (LOD) and limit of quantification (LOQ) were 0.0005 and 0.005 mg/kg, respectively. The recoveries of interlaboratory validation ranged from 83.4% to 117.3% and the coefficient of variation (CV) was 9.0%. All results were followed with Codex guideline (CAC/GL 40) and Ministry of Food and Safety guideline (MFDS, 2016). The proposed new analytical method proved to be accurate, effective, and sensitive for benzovindiflupyr determination and would be used as an official analytical method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.47-56
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• 2020

In this study, three levels of W/B(Water to Binder) ratio (0.37, 0.42, 0.47) and substitution ratio of GGBFS (Ground Granulated Blast Furnace Slag) rate (0 %, 30 %, 50 %) were considered to perform RCPT (Rapid Chloride Diffusion Test) at the 1,095 aged day. Accelerated chloride diffusion coefficient and passed charge of each concrete mixture were assessed according to Tang's method and ASTM C 1202, and improving behaviors of durability performance with increasing aged days are analyzed based on the test results of previous aged days from the preceding study. As the age of concrete increases, the passed charge and diffusion coefficient have been significantly reduced, and especially the concrete specimens containing GGBFS showed a significantly more reduction than OPC(Ordinary Portland Cement) concrete specimen by latent hydraulic activity. In the case of OPC concrete's results of passed charge, at the 1,095 days, two of them were still in the "Moderate" class. So, if only OPC is used as the binder of concrete, the resistance performance for chloride attack is weak. In this study, the time-parameters (m) were derived based on the results of the accelerated chloride diffusion coefficient, and the deterministic and probabilistic analysis for service life were performed by assuming the design variable as a probability function. For probabilistic service life analysis, durability failure probabilities were calculated using Monte Carlo Simulation (MCS) to evaluate service life. The service life of probabilistic method were lower than that of deterministic method, since the target value of PDF (Probability of Durability Failure) was set very low at 10 %. If the target value of PDF suitable for the purpose of using structure can be set and proper variability can be considered for each design variable, it is believed that more economical durability design can be made.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.305-314
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• 2018

The steel-plate concrete composite beam is composed of a steel plate, concrete and a shear connector to combine the two inhomogeneous materials. In general, the steel plate is assembled by welding an existing composite beam. In this study, a new steel-plate concrete composite (SPCC) beam was developed to reduce the size of the shear connector and improve its workability. The SPCC beam was composed of folded steel plates and concrete, without any shear connector. The folded steel plate was assembled with high strength bolts instead of welding. To improve the workability in field construction, a hat-shaped cap was attached in the junction with the slab. Monotonic two-point load testing was conducted under displacement control mode. The flexural strength of the SPCC beam specimen was calculated to be 76% of that of the complete composite beam by using the plastic stress distribution method and strain compatibility method. The cap acted as the stud and accessory. The synthesis rate could be increased by controlling the gap of the cap, and the bending performance could be evaluated by using the strain fitting method considering the synthesis rate of the SPCC beam.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.352-359
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• 2010

The objective of this paper is to study on the property transformation for materials and to evaluate the precision through marginal gap depending on heat-treatment of metal-porcelain by the gold electro-forming system. Specimens for evaluating property of hardness treat non-treat(HC), once(H1), twice(H2), and three times(H3) by heating, respectively. Specimens for marginal gap classified as each groups of special bonder(FS), special bonder, opaque(FO), special bonder, opaque, body(FB) and non-treatment(FC). As a result for micro-hardness test, the level of hardness on each groups of H1, H2, H3 decreased rather than HC group(p<0.05). In addition, marginal gap was not affected by the number of times being treated by heating. Therefore, the marginal fitness and the precision for mterials were not affected by the heat-treatment on the process to make GES metal-porcelain.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.22-27
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• 1997

특정 제품이 가진 "감성 이미지"란 그 제품의기능과 함께 제품의 감각적 요소 그리고 사용자가 제품에 대해 가진 개념적인 사고 과정의 산물이다. 감성이미지의 국제 비교 연구는 사용자가 특정 제품에 대해 가지고 있는 이미지를 국가나 문화의 맥락 속에서 상호 비교 평가하여, 각 국가나 사회집단을 특팅지울 수 있는 문화적 감성 요소를 추출하고자 하는 것이다. 즉, 각 국가의 생활문화 속에서 사용자들이 제품에 대해 가지는 감성이미지를 계량적으로 규명하고 비교 평가하며, 이 정보를 기초로 각국의 문화와 정서에 적합한 제품 디자인의 모형을 제시하는데 본 연구의 목적이 있다. 구체적인 연구방법은 우선, 자동차 제품을 중심으로 '제품 이미지'를 나타내는 '언어 이미지'스케일을 각 문화 집단 별로 구성한다. 이 제품 이미지에 대비하여, 감성적 요소로 선정된 표준 색채 스케일을 중심으로 나타난 집단의 '이미지'를 상호 비교 평가한다. 이 경우, 각 국가별 집단에서 특징적으로 나타나는 제품의 주요 특성이 감성 이미지로 표현되는 색채 이미지에 어떻게 반영되는가를 상호 비교한다. 이 연구에서는 특정 지역의 사람들이 제품에 적용하는 감성이미지는 색채나 기타 감성 요소에 대한 선호의 문제가 아니라 그 집단의 사람들이 그 제품을 통해 표현하고자 하는 사회적 표상의 반영이라는 것을 보여준다. 따라서, 제품의 이미지가 각 국가별로 공유되는 감성 이미지로 변환되기 위해서는 동일한 의미나 상징성을 지닌 감성 요소를 활용하여 그 제품의 이미지를 포장할 수 있는 방법을 적용하는것이다. 본 연구에서는 각 문화 집단들이 특정 제품에 대해 가지고 있는 사회적 표상(social representation) 체계를 색채스케일에서 나타난 감성 이미지를 통해 구체화하는 것이다.로서는 방전효율의 저하가 없는 양호한 성능을 보였으며, SC의 시범 작동시험을 실차(소나타 1800cc)에 장착하여 수행한 결과 20회 이상의 연속시동에서도 아무런 문제점 없이 잘 동작하였다.되는 데이타를 입력한후 마우스로 원하는 작업의 메뉴를 선택하면 된다. 방법을 타액과 혈청내 testosterone 농도 측정에 응용하여 RIA의 결과와 비교하여 본 바 상관관계가 타액에서 r=0.969, 혈청에서 r=0.990으로 두 결과가 잘 일치하였다. 본 실험에서 측정된 한국인 여성의 타액내 testosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the le

• Korean Journal of Organic Agriculture
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• v.26 no.2
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• pp.281-296
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• 2018

This study was conducted to evaluate the effect of different processing of rice on rumen fermentation in in vitro and in situ experiments. Different processing treatments (extruding, roasting, and steaming) were used in this study and all treatments were ground through a cyclone mill (Foss, Hillerød, Denmark) fitted with a 1 mm screen. Non-treated rice was considered to a control substrate. Then, all treatments were used in in vitro and in situ experiments. Total gas production and dry matter digestibility in control were lower than any other treatment at all incubation times (P<0.01). The lowest ammonia nitrogen ($NH_3-N$) concentration was observed in control among treatments at 6, 12, and 24 h incubation (P<0.01). Extruding had a highest total volatile fatty acids (VFA) concentration at 6, 12 h incubation (P<0.01) and Steaming exhibited a highest total VFA at 24 h (P<0.01). The lowest total VFA concentration was observed in control at 6, 12, and 24 h (P<0.01). In an in situ, The highest value of soluble fraction, degradation rates, effective degradability was observed in extruding (P<0.01). It was considered that feed processing increased dry matter digestibility, total VFA concentration, and decreased pH as well as $NH_3-N$ concentration indicating that processing may increase nutrient degradation of rice in the rumen.