• Fisheries and Aquatic Sciences
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• 제18권2호
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• pp.165-171
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• 2015

Abalone containing phlorotannins is produced by feeding the phlorotannin-rich brown seaweed Eisenia bicyclis after 4 days of starvation. Reverse-phase high-performance liquid chromatography (RP-HPLC) was used to isolate and quantify phlorotannins, which were identified by mass spectrometry and [$^1H$]-nuclear magnetic resonance to be the P1 compound, 7-phloroeckol, and eckol. When E. bicyclis was used as feed, P1 compound accumulated to an average of 1.60 mg/g dry weight of abalone muscle tissue after 18 d, 7-phloroeckolol to 0.21 mg/g after 16 d, and eckol to 0.22 mg/g after 12 d. Saccharina japonica was used as a control feed, and the abalone showed little or no accumulation of phlorotannins in muscle tissue. Feed consumption and growth rate were very similar when either E. bicyclis or S. japonica was fed for 20 d. Half-maximal reductions in the levels of P1 compound, 7-phloroeckol, and eckol accumulation were attained in 1.5, 1.9, and 3.4 days, respectively, after the feed was switched from E. bicyclis to S. japonica. Value-added abalone containing bioactive phlorotannins can be produced by simply changing the feed to the phlorotannin-rich E. bicyclis 18 d prior to harvesting.

• 음성과학
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• 제8권4호
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• pp.171-184
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• 2001

American English vowels and Korean vowels were compared by the plotformant method. For American English vowels, six General American English speakers pronounced English words in the b_t environment. For Korean vowels eight Kyongsang dialect speakers and eight Seoul dialect speakers pronounced Korean words in the environments of k_t, p_t and t_t. The formant plots were obtained by plotting F1/F2 tokens of 13 American English vowels on the F1xF2 plane. In spite of personal variations the 13 vowel spaces of all six American English speakers maintained their relative positions with some overlaps. Clear distinctions were made between i-I, e-$\varepsilon$, u-$\sigma$, and o-c. The domain of c and $\alpha$ overlapped for three American English speakers, but it did not for three other speakers. The 8 Korean vowel spaces of Kyongsang dialect speakers and Seoul dialect speakers were very similar and maintained their relative positions. No distinction was made between e and $\varepsilon$. In contrast with American English e which is a neutral vowel, Korean e was a back vowel. The comparison of 13 American English vowel positions and 8 Korean Vowel positions is expected to shed some light on the errors of English vowel pronunciation of Korean learners.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.171-173
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• 2015

본 논문에서는 DirectX 개발도구를 기반으로 3차원 입체 eBook을 쉽게 제작할 수 있는 저작도구 설계 방법을 제안한다. 제안하는 3D 저작 도구는 크게 3차원 객체 생성 및 수정, 텍스쳐 변경, 입체영상 모드 및 사진, 동영상 익스포트 기능으로 구성된다. 이러한 기능을 지원하기 위하여 3차원 객체를 생성하기 위한 데이터 구조, 색상차를 이용한 애너그리프 방식, 반디캡 라이브러리를 사용하여 동영상 익스포트 방법 등의 설계 방안을 제시한다.

• 한국환경농학회지
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• 제14권2호
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• pp.171-178
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• 1995

본 연구는 원제 phosalone (94.4%)에 함유된 불순물들의 동정과 원제 및 정제 phosalone의 in vitro와 in vivo에서의 독성효과를 조사하였다. 원제 phosalone에 대한 GC/MS 분석에서 phosalone oxon, 6-chloro-3-methylthio-2-oxobenzoxazole, 6-chloro-2-oxobenzoxazole, O,O,S-triethylphosphorodithioat (OOSTEPDT), dichlorophosalone 들 5개의 불순물이 동정되었으며, P-NMR 분석에서 OOSTEPDT와 phosalone oxon 등 2종의 불순물이 확인되었다. In vitro에서 원제 Phosalone과 정제 phosalone의 AchE와 BuChE에 대한 $k_i$ 값을 비교한 결과, 원제 phosalone이 정제 phosalone보다 약 10배 빠르게 ChE를 저해하는 것으로 나타났으며, cytosolic esterases에 대해서도 10배 정도 더 강한 저해력을 보였다. In vivo에서도 원제 phosalone이 정제 phosalone 보다 생쥐의 뇌 AChE의 활성을 약 35% 더 저해 하였으며, 쥐의 혈액 erythrocyte AChE와 plasma BuChE 그리고 cytosolic esterases의 활성도 더 심하게 저해하는 것으로 관찰되었다. 이러한 결과는 원제 phosalone 중 함유된 불순물들에 의한 것으로 사료되었으며, 특히 phosalone oxon에 의한 것으로 추정되었다.

• Nuclear Engineering and Technology
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• 제41권2호
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• pp.171-178
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• 2009

The rate of delayed hydride cracking (DHC), V, has been measured in cold-worked and stress-relieved Zircaloy-4 fuel cladding using the Pin-Loading Tension technique. At $250^{\circ}C$ the mean value of V from 69 specimens was $3.3({\pm}0.8)x10^{-8}$ m/s while the temperature dependence up to $275^{\circ}C$ was described by Aexp(-Q/RT), where Q is 48.3 kJ/mol. No cracking or cracking at very low rates was observed at higher temperatures. The fracture surface consisted of flat fracture with no striations. The results are compared with previous results on fuel cladding and pressure tubes.

• 한국인터넷방송통신학회논문지
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• 제15권1호
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• pp.171-178
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• 2015

IT 관련 교과에서 실습 교육이 그 어느 때보다 강조되고 있다. 이 글은 IT 교육을 위한 클라우드 컴퓨팅 기반의 가상 데스크탑 서비스 제공 방안과 효율적인 운영 관리 방안을 연구하였다. 구현된 가상 실습 환경 시스템을 이용하면 교과의 커리큘럼에 적합하도록 커스토마이징된 실습환경을 제공할 수 있다. 뿐만 아니라, 제안된 시스템을 이용할 경우 교과운영 사전에 미리 교과별로 프로비저닝 할 수 있다. 따라서 본 논문에서 산정한 규모와 운영 정책을 참고하여 여러 사이버대학이 공동 활용할 수 있는 클라우드 실습 포털시스템을 구축한다면 보다 효율적이고 효과적인 가상실습 교육 서비스 시스템을 구축하고 제공할 수 있을 것으로 예상된다.

• 한국정보시스템학회지:정보시스템연구
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• 제26권1호
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• pp.171-188
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• 2017

Purpose This study investigates the effects of trust and distrust on intention to purchase in open market, based on the idea that trust and distrust can co-exist. Specifically, this study approached the effects of trust and distrust of the open market on the intention to purchase from a two-dimensional perspective, and examined trustworthiness as the antecedents of trust and distrust. Design/Methodology/Approach In this study, we conducted a questionnaire survey on consumers who have actually purchased a product from open markets in Korea for two months. As a result, 141 users are chosen for the sample. We apply PLS (Partial Least Squares) structural equation modeling (SEM) to verify our theoretical model using the software application SmartPLS 3.0. Findings First, trust in open market positively affects intention to purchase, whereas distrust in open market negatively affects intention to purchase. Second, the three antecedents of trust (i.e. three factors constituting trustworthiness such as ability, benevolence and integrity) affect trust in open market. Third, integrity negatively affects distrust in open market. Since integrity plays an important role in building both trust and distrust in open market, the operators of open market should pay attention to managing their integrity.

• 한국지능시스템학회논문지
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• 제12권2호
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• pp.171-176
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• 2002

This paper describes a new automated analysis system for model plane engine. An automatic finite element (FE) mesh generation technique, which is based on the fuzzy knowledge processing and computational geometry technique, is incorporated into the system, together with one of commercial FE analysis codes, ANSYS, and one of commercial solid modelers, Designbase, The system allows a geometry model of concern to be automatically converted to different FE models, depending on physical phenomena of plane engine to be analyzed, i.e. deformation analysis, thermal analysis and so on. The FE models are then automatically analyzed by the FE analysis code. Among a whole process of analysis, the definition of a geometry model, the designation of local node patterns, the assignment of material properties and boundary conditions onto the geometry model are only the interactive processes to be done by a user. The interactive operations can be processed in a few minutes. The other processes which are time consuming and labour-intensive in conventional CAE systems are fully automatically performed in a personal computer environment. The proposed analysis system is successfully applied to evaluate a model plane entwine.

• Carbon letters
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• 제16권3호
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• pp.171-182
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• 2015

Mesophase pitch is an important starting material for making a wide spectrum of industrial and advanced carbon products. It is produced by pyrolysis of petroleum residues. In this work, mesophase formation behavior in petroleum residues was studied to prepare environmentally-benign mesophase pitches, and the composition of petroleum residues and its influence on the mesophase formation was investigated. Two petroleum residues, i.e., clarified oil s (CLO-1, CLO-2) obtained from fluid catalytic cracking units of different Indian petroleum refineries, were taken as feed stocks. A third petroleum residue, aromatic extract (AE), was produced by extraction of one of the CLO-1 by using N-methyl pyrrolidone solvent. These petroleum residues were thermally treated at 380℃ to examine their mesophase formation behavior. Mesophase pitches produced as a result of thermal treatment were characterized physico-chemically, as well as by instrumental techniques such as Fourier-transform infrared spectroscopy, nuclear magnetic resonance, X-ray diffraction and thermogravimetry/derivative thermogravimetry. Thermal treatment of these petroleum residues led to formation of a liquid-crystalline phase (mesophase). The mesophase formation behavior in the petroleum residues was analyzed by optical microscopy. Mesophase pitch prepared from CLO-2 exhibited the highest mesophase content (53 vol%) as compared to other mesophase pitches prepared from CLO-1 and AE.

• Mycobiology
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• 제37권3호
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• pp.171-182
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• 2009

Many aspergilli that belongs to ascomycetes have sexuality. In a homothallic or self-fertile fungus, a number of fruiting bodies or cleistothecia are formed in a thallus grown from a single haploid conidia or ascospores. Genome-sequencing project revealed that two mating genes (MAT) encoding the regulatory proteins that are necessary for controlling partner recognition in heterothallic fungi were conserved in most aspergilli. The MAT gene products in some self-fertile species were not required for recognition of mating partner at pheromone-signaling stage but required at later stages of sexual development. Various environmental factors such as nutritional status, culture conditions and several stresses, influence the decision or progression of sexual reproduction. A large number of genes are expected to be involved in sexual development of Emericella nidulans (anamorph: Aspergillus nidulans), a genetic and biological model organism in aspergilli. The sexual development process can be grouped into several development stages, including the decision of sexual reproductive cycle, mating process, growth of fruiting body, karyogamy followed by meiosis, and sporulation process. Complicated regulatory networks, such as signal transduction pathways and gene expression controls, may work in each stage and stage-to-stage linkages. In this review, the components joining in the regulatory pathways of sexual development, although they constitute only a small part of the whole regulatory networks, are briefly mentioned. Some of them control sexual development positively and some do negatively. Regarding the difficulties for studying sexual differentiation compare to asexual one, recent progresses in molecular genetics of E. nidulans enlarge the boundaries of understanding sexual development in the non-fertile species as well as in fertile fungi.