• International Journal of Contents
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• v.18 no.3
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• pp.1-10
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• 2022

The advancement of Internet technologies has provided a new and effective way to cultivate international talents. To investigate the effect of native English teachers' online synchronous classes on Chinese primary school students' oral English improvement, an 18-month quasi-experimental study was conducted on 300 primary school students in China. The experiment and control groups were provided biweekly synchronous online classes with native and non-native English teachers. SPSS was used to conduct Paired Sample T-Tests and analyze performance differentials. The results showed that online classes taught by native English teachers perform better than non-native English teachers in three areas: vocabulary accuracy, average sentence length, and phonological intonation.

• Journal of the Korea Safety Management & Science
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• v.8 no.1
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• pp.43-52
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• 2006

The goal of this study is to investigate the ergonomic factors in designing or selecting the hand tool handle. Electromyogram (EMG) were measured for various wrist postures and handle sizes under two loading conditions. Anthropometric data were measured and the correlation with EMG measurement data were analyzed. Investigations of this study show that wrist posture should be neutral for minimum muscle tension and optimum handle size can be found by measuring the EMG measurement data. It show that hand width and EMG measurement data is greatly correlated also. This study can be a guide of designing or selecting a hand tool, but further study with large sample sizes and various groups is needed for making general conclusion.

• Journal of Korean Society of Transportation
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• v.16 no.3
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• pp.113-121
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• 1998

본 연구에서는 신호제어 및 ITS 분야에 활용하기 위한 검지 시스템을 구성하기 위 한 알고리즘의 하나인 대기 행렬 계측 알고리즘을 개발하였다. 본 연구에서는 대기열의 속 성을 standing queue와 moving queue로 구분하여, 각 속성에 따라 대기열의 발생지점을 계측한다. 알고리즘의 평가는 아주대학교 앞 4지교차로의 한 접근로에서 실시되었다. 평가 항목으로는 오차율과 통계적 검정을 실시하였으며, standing queue와 moving queue에 대 하여 주·야간 각 50개씩 sample을 가지고 실시하였다. 평가 결과 standing queue는 주·야 간 모두 비교적 우수한 것으로 평가되었으나, moving queue는 미흡한 결과를 나타내어, 좀 더 보완이 필요한 것으로 나타났다. 대기열의 속성을 standing queue와 moving queue로 분리함으로써 접근로의 상황을 더욱 정확하게 판단할 수 있을 것으로 기대된다.

• Nuclear Engineering and Technology
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• v.35 no.4
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• pp.286-298
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• 2003

A steam explosion module, STX, has been developed using the mechanistic steam explosion analysis code, TEXAS-V, in order to estimate the dynamic load with steam explosion by implementing the module to the integrated safety analysis code, MELCOR. One of the difficulties in using mechanistic steam explosion codes is that they do not have any obvious criteria for defining some uncertain parameters such as triggering timing, triggering magnitude, mesh axial length and mesh cross-sectional area. These parameters have been user decision parts in the past. Steam explosion sample calculations and sensitivity studies on uncertain parameters were conducted to investigate those uncertain parameters. The TEXAS-V simulations were summarized in the format of a look-up table and a linear interpolation technique was adopted to calculate the steam explosion load between the data points in the table. The STX-module merged with MELCOR showed the same results as the original MELCOR and additionally it could estimate the steam explosion load in the reactor cavity.

• Journal of the Korean Chemical Society
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• v.60 no.3
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• pp.181-186
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• 2016

The hydrophilic ophthalmic lens with addition of 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA) and Ag nanoparticles were manufactured. And also, the cross-linker ethylene glycol dimethacrylate (EGDMA) and the initiator azobisisobutyronitrile (AIBN) were used for polymerization. The polymerization of the hydrogel lens material was conducted through thermal polymerization in 100 ℃ for 1h. The optical and physical characteristics of hydrogel lens were evaluated by measuring water content, refractive index and optical transmittance. The water content of sample containing HEA, HEMA and HPMA was in the average of 82.12%, 37.06% and 21.57%, respectively. And also, refractive index of the sample containing HEA, HEMA and HPMA was in the average of 1.3540, 1.4330 and 1.4649, respectively. In case of the optical properties of the sample, the results showed that the near-UV transmittance was 82.67%, 80.32% and 79.83%, and the visible transmittance was 89.72%, 88.24% and 86.89%, respectively. And also, optical transmittance of the sample containing Ag nanoparticles showed that the near-UV transmittance of 10.59% and visible transmittance of 43.74% were obtained. From the results, the molecular length influenced on the water content and refractive index of the polymerized material.

• Journal of the Korean GEO-environmental Society
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• v.12 no.6
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• pp.25-34
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• 2011

Dredged and reclaimed ground in progress at the West Coast has a high content of coarse particles. There will be different behaviors depending on the location of outlet and engineering properties of soil when its ground is dredged by a pump. Therefore, the experiments were conducted that were manufactured about the chamber equipment of length 2,650mm, width 770mm, height 735mm, experimented step filling method and water content about 300%, 500% and 700% respectively with SM and ML samples in order to realize segregating sediment characteristics of dredged ground with changing much fine. With results of analysis, ML sample by higher initial water content was reached to the period of complete sedimentation and coefficient of sedimentation consolidation increased with increases of diffusion distance. SM samples showed behavior of coarse soil with diffusion distance 120cm, diffusion distance of more than 120cm showed a similar tendency with ML sample under the influence of fines. In ML sample, it could be also found that lower depth and the more increasing diffusion distance increase in percentage of sieve #200 but water content decreases. In SM sample, it could be also found that coarse soil was piled at near the diffusion distance zone but fine soil was piled at the far diffusion distance zone and prominent difference showed between percentage of sieve #200 and water content(%) by boundary point 120cm~160cm of both samples. Also, shear strength was expressed ML-maximum 2.97kPa, SM-maximum 10.2kPa with diffusion distance.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.280-291
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• 2023

Purpose: As fire accidents happen at the production and storage sites of superabsorbent polymers for convenience of daily life, an experimental study was conducted to secure basic data to establish practical preventive measures against them. Method: The sample container (20cm width × 20cm length) was made into a rectangular cuboid with the heights of 3cm, 5cm, 7cm, and 14cm, respectively, to allow access to the infinite flat plane. The front and back of the container were covered with a 300-mesh stainless steel mesh for one-dimensional heat transfer. The sample container was placed in the center of the thermostatic bath, which was heated to a predetermined temperature by setting the thermostat program in advance, and it was determined to be 'ignited' when the central temperature of the sample rose by more than 20℃ above the set temperature, and "unignited" when it was maintained at an approximate value of the set temperature. Result: The critical autoignition temperature was calculated to be 217.5℃ when the height of the sample container was 3 cm, 212.5℃ when it was 5 cm, 202.5℃ when it was 7cm, and 187.5℃ when it was 14cm. The ignition induction time to reach the maximum temperature was 34hours for 3cm, 76hours for 5cm, 143hours for 7cm, and 318hours for 14cm. Conclusion: ① As the size of the container increased, the autoignition temperature decreased and the induction time to reach the maximum temperature increased. ② An apparent activation energy was calculated to be 44.92kcal/mol, with a correlation of 96.93%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1783-1788
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• 2009

We newly propose that we may reuse scrap powders ($Z_rO_2$+8 mol%-$Y_2O_3$) as $Y_2O_3$-stabilized zirconia (YSZ) sintered products through sintering process at 1550$^{circ}C$ for 2hrs. We also prepared the reference specimen from fresh $Z_rO_2$+30 mol%-$Y_2O_3$ powder mixture (celluar type with 1㎛-length). The reference sample showed a dense microstructure with grains of $\sim$10㎛ in diameter, while the sintered sample from scrap powder showed irregular grains of 1$\sim$30 ㎛ in diameter. Through XRD analysis, we confirmed that the reference sample has mixed phases of $Y_2O_3$(cubic), $Z_{r0.8}O_{1.9}$(cubic), and $Z_rO_2$(monoclinic), while the sintered YSZ sample from scrap powder has only tetragonal phase. Moreover, the sintered YSZ from scrap powder showed vickers hardness and apparent density more than 70 and 4.11 g/cc, which implies that it can be suitable for structural material application.

• Journal of the Korean Home Economics Association
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• v.8 no.1
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• pp.62-86
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• 1970

A study on the upper garment of Korean women, JUORI The upper garment of Korean women. JUGORI, is an inherited mode from the ancient clothing style in the various aspects based on the particulars of Korean clothes. The ancient style of clothes is originated from KWAMDUI belonging to inhabitants of Northern Territory of Korea. And it is quite different from Chinese clothes in lineage. However, this unicque mode of clothes has been much influnced by the Chinese culture and also by the climate of Korea. And it is quite different from Chinese clothes in lineage. However, this unicque mode of clothes has been much influnced by the Chinese culture and also by the climate of Korean penynsula. The changes of the pattern of JUGORI, in a word, is a sign of shortening tendency of size. This tendency of JUGORI is remarkably seen in the shortening of length and other parts are decreased in size. The JUGORI in the ancient age was fallen below the weist of woman, which is similar to Robe, and was worn with band. However, the length of the JUGORI has been gradually shortened, and therefore, GORUM took place of the band. The shortening tendency of JUGORI is seemed to be shown its sign in the initial time of its origin, because there are some evidences that the women in Sylla Dynasty, and this tendency has been much expedited during the period of Koryu Dynasty with influences of Monggorian culture (Won Lynasty of China) The oldest sample for data of JUGORI in nowaday is one the remains of Yi Dynasty, and this sample for data provides all the particulars of the modern pattern of JUGORI. The tendency of JUGORI had been continued even in Yi Dynasty, and at the end of the Dynasty, the clothes was shortened that the women felt inconvenient wearing it in the status of the shortened JUGORI which was even hardly cover the initial time of epoch of modernization induced from the Western civilization, and after 1920s and 1930s JUGORI become a larger tendency. This is a sing of revival of practical use and rationalization of JUGORI become a shortening tendency again, and the size is similar with that of early age of Yi Dynasty. Instead of these similarities, the particulars of modern JUGORI is weighing on much emphasis on curve beauty and expression of experior beauty. The reason is that, together with westernization of clothes, JUGORI became a special pattern of clothes as a traditional Korean women wears. The very thing explaining this pattern of JUGORI is the "ARIRANG DRESS". And there are some fashion using button instead of GORUM and half sleeve JUGORI for summer use which is regarded as a part of improved aspect of life in Korea. in Korea.

• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.391-397
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• 2009

Eurasian eagle owl (Bubo bubo kiautschensis) is a natural monument (No. 324) and is also classified as an endangered wildlife grade II the Ministry of Environment of Korea. Eurasian eagle owl is threatened by the human being. But the efficient rescue and treatment for Eurasian eagle owl are still problematic, due to lack of basic data. In this study, to obtain basic resources for establishing more efficient rescue system, we held a physical examination and measured size physical part. In addition, we analyzed blood sample and feces samples and autopsy. We conduct the physical examination with measuring tapes and scales for 16 live features and 11 dead features. After inhalation anesthesia take the blood samples from wing vein. Blood samples are analyzed in hematologic and chemistric methods. We collected the feces through individual floor of cages from 12 live features and conducted the feces analysis. Autopsy was conducted for 11 dead samples. In physical examination, the mean body weight and total length of live features was 2.26${\pm}$0.35kg, 61${\pm}$2.38cm, the mean body weight and total length of dead features was 1.57${\pm}$0.51kg, 59.31${\pm}$3.51cm. Mean PCV was 46.57${\pm}$4.97%, while mean TPP was 3.49${\pm}$0.57g/dL. In feces sample analysis, 9 of 12 owls(75%) were infested by gastrointestinal helminths. The infection rates were: Trematoda (41.7%), Capilaria sp.(66.7%), acanthocephalans (25%). In autopsy, we confirmed 11 features were infested by duplicated infection of more than 2 helminths. Result of this study will be used for establishing reference range for physical features, blood analysis in Eurasian eagle owl. Therefore, to obtain basic resources for establishing more efficient rescue system, we have to make long-term conservation plans for Eurasian eagle owl.