• 대한화학회지
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• 제32권2호
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• pp.85-93
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• 1988

등유전상수 용매로 취급되는 MeOH-nitromethane, MeOH-nitrobenzene 및 MeOH-ethylene glycol 혼합용매 하에서 t-butyl halides (X = Cl, Br, I)의 가용매 분해반응을 연구 하였다. MeOH-NM 및 MeOH-NB에서 t-butyl halide의 가메탄올 분해반응 속도는 40~100 % (v/v) MeOH 조성에서 최대치를 보였다. 최대속도 현상은 용매의 극성-편극성과 수소결합 주게능력의 협력적인 결과로 설명하였다. Y값의 변화로 부터 극성-편극성과 수소 결합 주게능력의 협력적인 결과로 설명하였다. Y값의 변화로 부터 극성-편극성과 수소결합 주게능력이 기질의 반응성에 미치는 효과를 논의 하였다. E.G.에서 기질의 반응성은 MeOH에 비해 20배 이상 빠름을 보였으며 이는 아마도 E.G.의 특이한 용매구조에 기인 한다고 여겨 진다.

• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.1981-1985
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• 2005

Kinetic studies have been performed for alkaline hydrolysis of a series of [(methoxy)(p-substituted styryl)carbene]pentacarbonyl chromium(0) complexes ($(CO)_5$Cr=$C(OCH_3)CH=CHC_6H_4X$, X = p-$OCH_3$, p-$CH_3$, H, p-Cl, p-$NO_2$). Second-order rate constants $(k_{{OH}^-})$ for the alkaline hydrolysis in 50% acetonitrile-water(v/v) were determined spectrophotometrically at various temperatures. At a low pH region (pH < 7.5), the observed rate constant $(k_{obs})$ remained constant with a small value, while in a high pH region (pH > 9.5), $k_{obs}$ increases linearly with increasing the pH of the medium. The second-order rate constants $(k_{{OH}^-})$ increase as the substituent X changes from a strong electron donating group to a strong electron withdrawing group. The Hammett plot obtained for the alkaline hydrolysis is consisted of two intersecting straight lines. The nonlinear Hammett plot might be interpreted as a change in the rate-determining step. However, the fact that the corresponding Yukawa-Tsuno plot is linear with $\rho$ and r values of 0.71 and 1.14, respectively indicates that the nonlinear Hammett plot is not due to a change in the rate-determing step but is due to ground-state stabilization through resonance interaction. The positive $\rho$ value suggests that nucleophilic attack by $OH^-$ to form a tetrahedral addition intermediate is the rate-determining step. The large negative ${\Delta}S^\neq$ value determined in the present system is consistent with the proposed mechanism.

• Journal of the Korean Wood Science and Technology
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• 제6권1호
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• pp.8-14
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• 1978

In order to determine the feeding value of t:1e waste wood of Lentinus eddodes, the waste wood was milled and treated with $Ca(OH)_2$ and cellulase, then raw waste wood and the treated waste wood were fed to broiler chicken and Korean native goates. The results obtained were as follows; 1. The chemical composition of the waste wood was c. protein 2.26%. c. fat 2.57%. c. fiber 44.60 and c. ash 5.58%. No differences were detected between the raw waste wood and $Ca(OH)_2$ or cellulase treated waste wood in chemical composition. 2. In amino acid composition. no cystine and methionine was showed, but trace amount of Vitamin A, $B_1$, and $B_2$, and cholin chloride were detected. 3. Trichoderma viride SANK. No. 16374 was used to decompose the cellulose. 4. In broiler performance, when waste wood meal was subsituted for 5% wheat bran, no adverse effect was showed on weight gain, feed in take and feed efficiency. But $Ca(OH)_2$ and cellulase treated waste wood meal could be subsituted for 8% wheat bran. 5. In Korean native goat performance, feeding waste wood meal subsituted by 50% various bran (25% defatted rice bran and 25% barley bran) had no adverse effect on growth and feed efficiency. 6. Considering the above results, though the waste wood meal could be replaced to part of various bran, there was a bottle-neck to process the waste wood. The waste wood of Lentinus edodes was little feeding value on bed of ruminant.

• 유통과학연구
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• 제18권1호
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• pp.59-69
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• 2020

Purpose: This study aims to examine such relationships as the experiential value that customers respond to with regard to maintenance service by empirically revealing how the quality of auto maintenance and repair service affects both customer satisfaction and intention to reuse the same service through the Perceived-experiential Value of customers. Research design, data and methodology: The research model was designed with service qualities such as human quality, material quality, interaction quality, and system quality as independent variables, perceived-experiential value as a parameter, and service satisfaction and return visit intention as dependent variables. Through a questionnaire composed of 24 items, a total of 319 survey data from customers with the experience of using car maintenance service centers in Korea were collected and analyzed using a structural equation. Results: The material quality did not affect the customers' perceived-experiential value, whereas the interaction quality had the greatest influence. It is confirmed that human quality, interaction quality, and system quality can generate customer satisfaction and repurchase intention through the perceived-experiential value. Conclusions: The experiential value of customers can play an important medium role in improving satisfaction, with customers considering interaction quality important. Therefore, the auto maintenance and repair service should consider relationship-focused service strategies.

• The Journal of Asian Finance, Economics and Business
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• 제6권2호
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• pp.105-117
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• 2019

The study aims to investigate the effects of brand value in the oriental medicine cosmetics market, as perceived by consumers, on brand satisfaction, brand loyalty, and purchase intention. The subjects were Korean and Chinese female consumers, the primary consumers of oriental medicine cosmetics. A total of 615 sample surveys were analyzed from consumers who have experience using oriental medicine cosmetics. Out of the sample, 264 respondents had used Oriental medicine cosmetics for one to four years, 199 respondents for more than four years, and 108 respondents for three months to a year. Based on existing research, we categorized the value of oriental medicine cosmetics brands into four dimensions: emotional, social, functional, and epistemic values. Whether brand satisfaction and brand loyalty can be mediating factors in brand value influencing purchase intention was inspected through several hypotheses. As a result, except for the epistemic value factor, the brand value factors were found to have a positive effect on brand satisfaction and brand loyalty. In addition, emotional, social, and functional brand value factors influence purchase intention through brand loyalty, and it was found that brand loyalty is an important factor for oriental medicine cosmetics consumers, however mediator effects did not appear for brand satisfaction.

• 펄프종이기술
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• 제35권4호
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• pp.1-7
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• 2003

In this study, fiber mechanical pretreatment before refining was executed with the addition of papermaking addiditives to find synergistic effects on fiber property improvement. Three fiber furnishes (SwBKP, KOCC, and BCTMP), and five different additives (CMC, CPAM, PEO, NaOH, $Na_2O_2$) were used. It was confirmed again that fiber mechanical pretreatment using Hobart mixer was a special way to modify fiber properties, where fiber WRV (water retention value) increases without losing fiber length. For SwBKP, addition of small amount of CMC (0.2％ OD basis), and for KOCC, PEO (0.2％ OD basis) caused additional significant improvement of the fiber furnish properties, respectively. Other additives did not cause adverse effects on the mechanical pretreatment, or better. For BCTMP, NaOH addition followed by mechanical pretreatment caused more than 20％ improvement in tensile and tear strength simultaneously, compared to the control. The yellowing caused by the treatment of NaOH on BCTMP could be minimized by using $Na_2O_2$ without losing the positive effect of NaOH.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.110.2-110
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• 2002

Evolutionary Algorithm is the general method that can search the optimum value for the various problems. Evolutionary method consists of random selection, crossover, mutation, etc. Since the next generation is selected based on the fitness values, the crossover between chromosomes does not have any restrictions. Not only normal marriage but also consanguineous marriage will take place. In human world, consanguineous marriage was reported to cause various genetic defects, such as poor immunity about new diseases and new environment disaster, These problems translate into searching for the local optimum, not the global optimum. So, a new evolutionary algorithm is needed that prevents traps to...

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.612-617
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• 2000

The vibrational characteristics of Langevin-type piezoelectric torsional transducers have been studied theoretically and experimentally in this paper. The differential equations of piezoelectric torsional motion have been derived in terms of the circumferential displacement and the electric potential. Solutions of the boundary-value problem have yielded the natural frequencies and mode shapes of the transducers. The theoretical solutions have been verified by comparing the numerical results with experimental ones.

• 한국환경농학회지
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• 제29권2호
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• pp.102-108
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• 2010

과실비대기 중에 수산화칼슘의 엽면살포가 '대월' 복숭아의 수체생육 및 과실품질에 미치는 영향을 구명하고자 실험을 수행하였다. 적과 후 수산화칼슘 1, 2, 5, 10 $g{\cdot}L^{-1}$을 일주일 간격으로 엽면살포한 결과, 신초생장은 대조구에 비해 현저히 억제되었다. 신초 기부로부터 5번째 잎의 엽색도를 측정한 결과, 수산화칼슘 엽면살포구에서 평균 42.1 SCDSV로 대조구의 40.9 SCDSV보다 높게 나타났으며, 광합성률은 수산화칼슘을 고농도로 처리할수록 크게 증가하였다. 과실 품질을 조사한 결과, 과중은 고농도의 수산화칼슘을 처리할 수록 유의하게 증가하였다. 당 함량은 대조구가 8.78 $^{\circ}Brix$로 가장 낮았던 반면, 수산화칼슘 처리구에서 9.17, 9.22, 9.71, 10.58 $^{\circ}Brix$로 고농도로 처리할수록 증가하였다. 산도와 안토시아닌 함량은 모든 처리구에서 유의성이 인정되지 않았으며 과피와 과육의 경도는 고농도의 수산화칼슘 처리에 의해 유의하게 증가하였다. 잎의 형태적 관찰 결과, 대조구의 책상조직(63.5 ${\mu}m$)에 비하여, 수산화칼슘 처리구는 86.5, 87.5, 93.6, 107.4 ${\mu}m$로 처리농도가 높을수록 조직이 건전하게 유지되고 잎의 두께 또한 증가하였다. 과실의 표피와 하피의 세포벽을 관찰한 결과, 수산화칼슘 엽면살포에 의해 세포벽의 두께가 증가하는 것을 확인할 수 있었다.

• Journal of the Korean Data and Information Science Society
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• 제25권1호
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• pp.255-261
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• 2014

Many studies have estimated a mixture of binomial distributions. This paper considers an extension, a mixture of shifted binomial distributions, and the estimation of the distribution. The range of each component binomial distribution is rst evaluated and then for each possible value of shifted parameters, the EM algorithm is employed to estimate those parameters. From a set of possible value of shifted parameters and corresponding estimated parameters of the distribution, the likelihood of given data is determined. The simulation results verify the performance of the proposed method.