• 정보보호학회논문지
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• 제24권5호
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• pp.817-838
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• 2014

금융기관 및 통신사 등 대량의 데이터를 다루는 회사에서 테스트환경은 구축 비용문제로 인한 스토리지 용량의 한계 및 중요정보 컬럼의 변환 등으로 운영환경과 항상 동일한 것은 아니다. 따라서, 이러한 테스트환경과 운영환경이 동일하지 않아 발생하는 SQL 성능저하는 예상치 못한 거래장애로까지 연결되어 기업의 금전적 손실 및 고객민원, 신뢰도 하락을 발생시키는 중요 원인이 되고 있다. 그동안 SQL과 관련한 성능연구는 DBMS Optimizer와 관련한 튜닝연구 중심으로 이루어져, 이러한 문제에 대해서는 다루어지지 않았다. 따라서, 본 논문에서는 테스트환경과 운영환경의 차이로 발생하는 SQL의 성능저하에 따른 온라인 거래장애 방지를 위해 개선된 SQL 성능 기반의 IT 응용프로그램 변경관리 프로세스를 제시하여 그 효과성을 검증한다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.13-17
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• 2004

The aim of this study was to investigate genetic development and genotype${\times}$environment interactions (GEI) in postweaning body weight of fattening bulls at the end of test period (WT-T) under various beef fattening environments. Data on a total of 24,247 fattening bulls obtained from the industrial farm, breeding farms and testing stations were used. Heritability estimates for WT-T in all environments were nearly similar. Significant genetic developments of sire, dam and progenies for WT-T were observed in all environments. However, many differences in annual genetic developments between the environments were significant. The genetic correlations for WT-T between industrial farm and breeding farms, industrial farm and testing stations and breeding farms and testing stations were respectively 0.004, 0.004 and 0.013. These low estimates of genetic correlations and significant differences in genetic developments among environments clearly show the existence of GEI for WT-T among various fattening environments. Results of this study indicate the need for environment-specific genetic evaluation and selection of beef bulls for commercial beef production.

• 음성과학
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• 제14권1호
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• pp.105-119
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• 2007

The purpose of this study is to examine Korean students' production and perception of word-final stop voicing in light of their overseas experience. Subjects were English native speakers, Korean university students with residence experience in America, Korean university students without residence experience in America, and Korean elementary school students. They participated in both production and perception tests. Results showed that the students' production and perception with residence experience in America appeared quite similar to those of the English native speakers. In the production tests, we noticed somewhat different results in temporal and frequency features. The one-year residence in America had some influence on their frequency features, but not the temporal features in the word final stop production. That difference could be seen in the perception tests, too. We could not find any difference in the identification test of the final release environment between the Korean university students who had studied abroad and those who didn't. Rather the difference could be found in the cue influence test in both the final release and non-release environments.

• 대한산업공학회지
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• 제35권1호
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• pp.15-39
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• 2009

Advanced planning and scheduling (APS) refers to a manufacturing management process by which raw materials and production capacity are optimally allocated to meet demand. APS is especially well-suited to environments where simpler planning methods cannot adequately address complex trade-offs between competing priorities. However, most scheduling problems of APS in the real world face both inevitable constraints such as due date, capability, transportation cost, set up cost and available resources. In this survey paper, we address three crucial issues in APS, including basic scheduling model, job-shop scheduling (JSP), assembly line balancing (ALB) model, and integrated scheduling models for manufacturing and logistics. Several evolutionary algorithms which adapt to the problems are surveyed and proposed; some test instances based on the practical problems demonstrate the effectiveness and efficiency of evolutionary approaches.

• 산업경영시스템학회지
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• 제5권7호
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• pp.1-7
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• 1982

This thesis deals with the method of Work Sampling to compare production activity due to change of productivity, workmen's productivity environment, nonproductivity of machine and plant when there is a process before and after change of work environments. So, this study takes $x^2$ - test to discover significant change of process, and obtains Proper observation number due to ratio difference-test over change of productivity before and after process change. Therefore, this thesis represent statistically effective results between two periods before and after process change.

• ALGAE
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• 제29권4호
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• pp.311-319
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• 2014

The biocide sodium hypochlorite (NaOCl) is widely used for controlling algal growth, and this application can be extended to marine environments as well. This study evaluates the biocidal efficiency and cellular toxicity of NaOCl on the harmful dinoflagellate Cochlodinium polykrikoides, with emphasis on pigment production and antioxidant enzyme activity. The test organism showed dose-dependent decrease in growth rate on exposure to NaOCl, and the 72 h $EC_{50}$ was measured to be $0.584mg\;L^{-1}$. NaOCl significantly decreased pigment levels and chlorophyll autofluorescence intensity, indicating possible detrimental effects on the photosystem of C. polykrikoides. Moreover, it significantly increased the activities of antioxidant enzymes, suggesting the production of reactive oxygen species in the cells. These data indicate that NaOCl exerted deleterious effects on the photosynthetic machinery and induced oxidative damage in the dinoflagellate and this biocide could be effectively used for the control of algal blooms.

• 한국축산시설환경학회지
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• 제4권2호
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• pp.113-126
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• 1998

This study was conducted to develop pig-housings based on the forecasting models of swine production, the weather conditions, and so on in Korea. The Korean pig-housings were developed according to the following basis : 1. They should be suitable to domestic weather conditions. 2. They should be designed based on the forecasting models of swine production of farrow to finish operation among the forecasting models of swine production in Korea. 3. Proper environments should be offered to pigs according to the growth. 4. The environmental control, the treatment of swine wastewater, and so on should be interrelated. 5. Manual energy should be saved by effective arrangements of pig-housings. In the future, performance test of the Korean pig-housings and development of facility automation systems which are suitable to these should be accomplished.

• 전자공학회논문지A
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• 제31A권9호
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• pp.156-163
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• 1994

A new circuit simulator for submicron MOS desings was developed by enhancing SPICE3. The minimum conductance stepping, source stepping and pseudo transient methods are applied to improve the convergence. and SECSPICE uses the variation rate of the node volgage in the timestep algorithm. The modified BSIM model was implemented in SECSPICE for submicron MOS designs. And it gives the powerful user environments such as graphic user environments. As the results of test using real measured device data and circuits used in real production desing, we found it gave more accurage results than BSIM and the execution speed was 1.5~2.8 times faster than SPICE3.

• Journal of Positioning, Navigation, and Timing
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• 제9권3호
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• pp.273-284
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• 2020

The performance of Global Navigation Satellite System (GNSS) chipset and Inertial Measurement Unit (IMU) sensors embedded in smartphones for location-based services (LBS) is limited due to the economic reasons for their mass production. Therefore, it is necessary to efficiently process the output data of the smartphone's embedded sensors in order to derive the optimum navigation values and, as a previous step, output performance of smartphone embedded sensors needs to be verified. This paper analyzes the navigation performance of such devices by processing the raw measurements data output from smartphones. For this, up-to-dated versions of smartphones provided by Samsung (Galaxy s10e) and Xiaomi (Mi 8) are used in the test experiment to compare their performances and characteristics. The GNSS and IMU data are extracted and saved by using an open market application software (Geo++ RINEX Logger & Mobile MATLAB), and then analyzed in post-processing manner. For GNSS chipset, data is extracted from static environments and verified the position, Carrier-to-Noise (C/N₀), Radio Frequency Interference (RFI) performance. For IMU sensor, the validity of navigation and various location-based-services is predicted by extracting, storing and analyzing data in static and dynamic environments.

• Corrosion Science and Technology
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• 제11권5호
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• pp.196-204
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• 2012

Corrosion failure of petrochemical facilities is one of the difficulties in maintenance, since operating conditions of crude oil production, storage, and refinement are very aggressive. UNS N08810, which has been used for crude oil transportation pipes and storage tanks in petrochemical industries, shows good resistance to general corrosion and localized corrosion in several environments. Among its environments, UNS N08810 showed better corrosion resistance in fuel gas containing sulfuric acid and phosphoric acid and sulfur. However, ductility and toughness at high temperature over about $500^{\circ}C$ were greatly reduced due to microstructural change. In general, welding process is the representative method to join the parts in industrial components. Because the alloy by welding can be sensitized and corroded, the manufacturing process should be controlled. In this work, UNS N08810 was used and heat treatment conditions including solution and stabilization treatments were controlled. Oxalic acid etch test by ASTM A262 Practice A was done to evaluate the qualitative sensitization in room temperature. Huey test by ASTM A262 Practice C was done to evaluate the intergranular corrosion rate in boiling 65% $HNO_3$ solution. Also, the microstructure by thermal history was analyzed. Experimental alloy showed high intergranular corrosion rate and its corrosion mechanism was elucidated.