• Title/Summary/Keyword: Directed evolution

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Study to Select a Strategic Fisheries for the Encouragement of a Long Term Planning Project in the Korean Fishing Industry. (한국어업의 장기적 진흥계획을 위한 전략 업종 선정에 관한 연구)

  • 장수호
    • The Journal of Fisheries Business Administration
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    • v.1 no.1
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    • pp.19-68
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    • 1970
  • This is a study of a long term project to encourage the Korean fishing industry. It seeks to supply a sound theoretical background in an attempt to liberalize the capital investment of the industry. However, the discussions developed in this thesis are based on, the existing world's fisheries resources, the possibility of their prospective cultivation, and the analysis of the evolution of Korean fisheries and fisheries organization. According to the reasults of the analysis ; out of the prospective world fisheries resources which are estimated at about 200 millions m/t the total yield per year is only about 70 millions m/t (1969), and Korea occupies only 850 thousands m/t. This therefore means that the Korean fishing industry allows much room for further growth. But the purpose of Korea's existing fishing industry organizations is entirely directed toword coastal fisheries and their functions never reache beyond the limit of off-shore fisheries. Thus almost 99% of the fisheries population engage in small scale fisheries along the coast line. The result is that the resource are almost exhausted by such over-exploitation. Being faced by this fact, it is of urgent necessity to modernize the management of fisheries as well as to encourage larger scale management of fisheries industries. This should be accompanied by the liberalization of capital investment. For this purpose this study also recommends the unification or annexation of small organizations to establish larger ones that will function for a larger scale industry. and further this study recommends that, in order to reorganize the existing fisheries organizations, a principle of selection should be applied in the areas of (1) maximum sustainable yields, (2) the possibility of forming an enterprise and (3) the maintenance of organization stability.

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Characterization of Squalene Synthase Inhibitor Isolated from Curcuma longa (울금(Curcuma longa)으로부터 분리한 squalene synthase 저해물질의 특성)

  • Choi, Sung-Won;Yang, Jae-Sung;Lee, Han-Seung;Kim, Dong-Seob;Bai, Dong-Hoon;Yu, Ju-Hyun
    • Korean Journal of Food Science and Technology
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    • v.35 no.2
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    • pp.297-301
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    • 2003
  • An inhibitor of squalene synthase, a key enzyme in the cholesterol biosynthetic pathways and a target for improved agents to lower plasma levels of low-density lipoprotein, was sequentially purified from Curcuma longa by acetone extraction, silica gel column chromatography, and sephadex LH-20 column chromatography. Active compound, YUF-01, was successfully purified and analyzed as $C_{20}H_{21}O_6$ by electron ionization mass spectrum. Through $^1H-NMR$ and $^{13}C-NMR$ analyses, YUF-01 was identified as curcumin, which showed strong inhibition of squalene synthase.

An Analysis of 30 Years of Literature on the International Adjustment on of International Expatriate Managers: Bibliometric Analysis using CiteSpace (해외파견관리자의 국제적응에 관한 30년간의 문헌 분석- CiteSpace를 이용한 계량서지학적 분석)

  • Ma, Chao;Kwon, Jong-Wook;Zhang, Yong-Feng;Pan, Jing-Jing
    • Korea Trade Review
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    • v.44 no.5
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    • pp.1-16
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    • 2019
  • As the activities of global enterprises have become more globalized and the labor movement among nations has increased, many studies have been carried out on the effective adjustment of expatriate managers. By examining the literature over the past 30 years on the adjustment of expatriate managers, this study identified major research trends and presented future research directions. While prior studies have often been cumbersome, time-consuming, and dependent on the researchers' subjective judgments, this study performs a bibliometric analysis using quantitative and visualized reference materials to provide a map showing the evolution process of existing research on the adjustment of expatriates. Using the CiteSpace program, this study conducted a bibliometric analysis of 517 papers focusing on major research trends, research countries, research institutions, authors, and journals. Study results found that the study of international adjustment was mainly focused on self-directed senders, attribution adaptations, and personal characteristics. The United States, Britain, and Australia were the most represented countries, while the most influential institutions included Aarhus University, the University of Wisconsin, and Hong Kong Baptist University. As one of the leading researchers, Selmer of Orhuss University published 19 papers, followed by Luring of Orhuss University. The Journal of International Business Studies (JIBs) most frequently featured studies of overseas expatriate adjustment.

Novel LTE based Channel Estimation Scheme for V2V Environment (LTE 기반 V2V 환경에서 새로운 채널 추정 기법)

  • Chu, Myeonghun;Moon, Sangmi;Kwon, Soonho;Lee, Jihye;Bae, Sara;Kim, Hanjong;Kim, Cheolsung;Kim, Daejin;Hwang, Intae
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.3
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    • pp.3-9
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    • 2017
  • Recently, in 3rd Generation Partnership Project(3GPP), there is a study of the Long Term Evolution(LTE) based vehicle communication which has been actively conducted to provide a transport efficiency, telematics and infortainment. Because the vehicle communication is closely related to the safety, it requires a reliable communication. Because vehicle speed is very fast, unlike the movement of the user, radio channel is rapidly changed and generate a number of problems such as transmission quality degradation. Therefore, we have to continuously updates the channel estimates. There are five types of conventional channel estimation scheme. Least Square(LS) is obtained by pilot symbol which is known to transmitter and receiver. Decision Directed Channel Estimation(DDCE) scheme uses the data signal for channel estimation. Constructed Data Pilot(CDP) scheme uses the correlation characteristic between adjacent two data symbols. Spectral Temporal Averaging(STA) scheme uses the frequency-time domain average of the channel. Smoothing scheme reduces the peak error value of data decision. In this paper, we propose the novel channel estimation scheme in LTE based Vehicle-to-Vehicle(V2V) environment. In our Hybrid Reliable Channel Estimation(HRCE) scheme, DDCE and Smoothing schemes are combined and finally the Linear Minimum Mean Square Error(LMMSE) scheme is applied to minimize the channel estimation error. Therefore it is possible to detect the reliable data. In simulation results, overall performance can be improved in terms of Normalized Mean Square Error(NMSE) and Bit Error Rate(BER).

An Interpretation of the Korean Fairy-Tale "Borrowed Fortune From Heaven" From the Perspective of Analytical Psychology (한국민담 <하늘에서 빌려온 복>에 대한 분석심리학적 이해)

  • Kihong Baek
    • Sim-seong Yeon-gu
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    • v.38 no.1
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    • pp.112-160
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    • 2023
  • This study examined the Korean folklore "Borrowed Fortune from Heaven" from the perspective of Analytical Psychology, considering it a manifestation of the human psyche, and tried to gain a deeper understanding of what happens in our mind. Through the exploration, the researcher was able to re-identify the ongoing psychological process operating in the depths of our mind, pertaining to the emergence of a new dimension of consciousness. Particularly the researcher was able to gain some insights into how the potential psychic elements for the new consciousness are prepared in the unconscious, how they get integrated into the conscious life, and what is essential for the accomplishment of the process. The tale begins with a poor woodcutter who, in order to escape from poverty, starts gathering twice as much firewood. However, the newly acquired amount disappears overnight, so the woodcutter gets perplexed and curious about where it goes and who is taking it. He seeks to find out the truth, which leads him to an unexpected journey to Heaven. There he learns the truth concerning his very tiny amount of fortune, and discovers another big fortune for an unborn person. By pleading with the ruler of Heaven, the woodcutter borrows that grand fortune, on the condition that he must return it to the owner when the time comes. After that, the woodcutter's life undergoes a series of changes, in which he finally becomes a wealthy farmer, but gradually is reminded more and more that the destined time is approaching. In the end, the fortune is completely transferred to the original owner, resulting in a dramatic twist and the creation of a new life circumstances. The overall plot can be understood as a reflection of the psychological process aiming at the evolution of consciousness through renewal. In this context, the woodcutter can be considered a psychic element that undergoes a continuous transformation in preparation for participating in the upcoming new consciousness. In other words, the changes brought about by this figure can be interpreted as a gradual and increasingly detailed foreshadowing of what the forthcoming new consciousness would be like. Interestingly, as the destined time approaches, the protagonist's anguish in conflict reaches its climax, despite his good performance in his role until then. This effectively portrays the difficulty of achieving a new dimension of consciousness, which requires moving past the last step. All the events in the story ultimately converge at this point. After all, the resolution occurs when the protagonist lets go of everything he has and follows the will of Heaven. This implies what is essential for the renewal of consciousness. Only by completely complying with the entire mind, the potential constituents of the new consciousness that should play important roles in a renewal and evolution of consciousness through experiencing, can participate in the ultimate outcome. As long as they remain trapped in any intermediate stage, the totality of the psyche would develop another detour aiming at the final destination, which means the beginning of another period of suffering carrying a purposeful meaning. The tale suggests that this truth will be applied everywhere that renewal of consciousness is directed, whether for an individual or a society.

Management of the Development of Insecticide Resistance by Sensible Use of Insecticide, Operational Methods (실행방식 측면에서 살충제의 신중한 사용에 의한 저항성 발달의 관리)

  • Chung, Bu-Keun;Park, Chung-Gyoo
    • Korean journal of applied entomology
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    • v.48 no.2
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    • pp.123-158
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    • 2009
  • An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

Optimization of Multiclass Support Vector Machine using Genetic Algorithm: Application to the Prediction of Corporate Credit Rating (유전자 알고리즘을 이용한 다분류 SVM의 최적화: 기업신용등급 예측에의 응용)

  • Ahn, Hyunchul
    • Information Systems Review
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    • v.16 no.3
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    • pp.161-177
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    • 2014
  • Corporate credit rating assessment consists of complicated processes in which various factors describing a company are taken into consideration. Such assessment is known to be very expensive since domain experts should be employed to assess the ratings. As a result, the data-driven corporate credit rating prediction using statistical and artificial intelligence (AI) techniques has received considerable attention from researchers and practitioners. In particular, statistical methods such as multiple discriminant analysis (MDA) and multinomial logistic regression analysis (MLOGIT), and AI methods including case-based reasoning (CBR), artificial neural network (ANN), and multiclass support vector machine (MSVM) have been applied to corporate credit rating.2) Among them, MSVM has recently become popular because of its robustness and high prediction accuracy. In this study, we propose a novel optimized MSVM model, and appy it to corporate credit rating prediction in order to enhance the accuracy. Our model, named 'GAMSVM (Genetic Algorithm-optimized Multiclass Support Vector Machine),' is designed to simultaneously optimize the kernel parameters and the feature subset selection. Prior studies like Lorena and de Carvalho (2008), and Chatterjee (2013) show that proper kernel parameters may improve the performance of MSVMs. Also, the results from the studies such as Shieh and Yang (2008) and Chatterjee (2013) imply that appropriate feature selection may lead to higher prediction accuracy. Based on these prior studies, we propose to apply GAMSVM to corporate credit rating prediction. As a tool for optimizing the kernel parameters and the feature subset selection, we suggest genetic algorithm (GA). GA is known as an efficient and effective search method that attempts to simulate the biological evolution phenomenon. By applying genetic operations such as selection, crossover, and mutation, it is designed to gradually improve the search results. Especially, mutation operator prevents GA from falling into the local optima, thus we can find the globally optimal or near-optimal solution using it. GA has popularly been applied to search optimal parameters or feature subset selections of AI techniques including MSVM. With these reasons, we also adopt GA as an optimization tool. To empirically validate the usefulness of GAMSVM, we applied it to a real-world case of credit rating in Korea. Our application is in bond rating, which is the most frequently studied area of credit rating for specific debt issues or other financial obligations. The experimental dataset was collected from a large credit rating company in South Korea. It contained 39 financial ratios of 1,295 companies in the manufacturing industry, and their credit ratings. Using various statistical methods including the one-way ANOVA and the stepwise MDA, we selected 14 financial ratios as the candidate independent variables. The dependent variable, i.e. credit rating, was labeled as four classes: 1(A1); 2(A2); 3(A3); 4(B and C). 80 percent of total data for each class was used for training, and remaining 20 percent was used for validation. And, to overcome small sample size, we applied five-fold cross validation to our dataset. In order to examine the competitiveness of the proposed model, we also experimented several comparative models including MDA, MLOGIT, CBR, ANN and MSVM. In case of MSVM, we adopted One-Against-One (OAO) and DAGSVM (Directed Acyclic Graph SVM) approaches because they are known to be the most accurate approaches among various MSVM approaches. GAMSVM was implemented using LIBSVM-an open-source software, and Evolver 5.5-a commercial software enables GA. Other comparative models were experimented using various statistical and AI packages such as SPSS for Windows, Neuroshell, and Microsoft Excel VBA (Visual Basic for Applications). Experimental results showed that the proposed model-GAMSVM-outperformed all the competitive models. In addition, the model was found to use less independent variables, but to show higher accuracy. In our experiments, five variables such as X7 (total debt), X9 (sales per employee), X13 (years after founded), X15 (accumulated earning to total asset), and X39 (the index related to the cash flows from operating activity) were found to be the most important factors in predicting the corporate credit ratings. However, the values of the finally selected kernel parameters were found to be almost same among the data subsets. To examine whether the predictive performance of GAMSVM was significantly greater than those of other models, we used the McNemar test. As a result, we found that GAMSVM was better than MDA, MLOGIT, CBR, and ANN at the 1% significance level, and better than OAO and DAGSVM at the 5% significance level.