• Title/Summary/Keyword: 수렴

Search Result 4,087, Processing Time 0.03 seconds

Impact of East Asian Summer Atmospheric Warming on PM2.5 Aerosols (동아시아 지역의 여름철 온난화가 PM2.5 에어로졸에 미치는 영향)

  • So-Jeong Kim;Jae-Hee Cho;Hak-Sung Kim
    • Journal of the Korean earth science society
    • /
    • v.45 no.1
    • /
    • pp.1-18
    • /
    • 2024
  • This study analyzed the effect of warming on PM2.5 aerosol production in mid-latitude East Asia during June 2020 using PM2.5 aerosol anomalies, which were identified by incorporating meteorological and climate data into the Weather Research Forecasting model coupled with Chemistry (WRF-Chem) model. The decadal temperature change trend over a 30-year period (1991-2020) in East Asia showed that recent warming has been greater in summer than in winter. Summer warming in East Asia generated low and high pressure in the lower and upper troposphere, respectively, over China. The boundary between the lower tropospheric low and upper tropospheric high pressure sloped along the terrain from the Tibetan Plateau to Korea. The eastern China, Yellow Sea, and Korean regions experienced a convergence of warm and humid southwesterly airflows originating from the East China Sea with the development of a northwesterly Pacific high pressure. In June 2020, the highest temperatures were observed since 1973 in Korea. Meanwhile, enhanced warming in East Asia increased the production of PM2.5 aerosols that travelled long distances from eastern China to Korea. PM2.5 anomalies, which were derived solely by inputting meteorological and climatic data (1991-2020) into the WRF-Chem model and excluding emission variations, showed a positive distribution extending from eastern China to South Korea across the Yellow Sea as well as over the Pacific Northwest. Thus, the contribution of warming to PM2.5 aerosols in East Asia during June 2020 was more than 50%. In particular, PM2.5 aerosols were transported from eastern China to Korea through the Yellow Sea, where the warm and humid southwesterly airflows implied wet scavenging of sulfate but promoted nitrate production.

Evaluating Reverse Logistics Networks with Centralized Centers : Hybrid Genetic Algorithm Approach (집중형센터를 가진 역물류네트워크 평가 : 혼합형 유전알고리즘 접근법)

  • Yun, YoungSu
    • Journal of Intelligence and Information Systems
    • /
    • v.19 no.4
    • /
    • pp.55-79
    • /
    • 2013
  • In this paper, we propose a hybrid genetic algorithm (HGA) approach to effectively solve the reverse logistics network with centralized centers (RLNCC). For the proposed HGA approach, genetic algorithm (GA) is used as a main algorithm. For implementing GA, a new bit-string representation scheme using 0 and 1 values is suggested, which can easily make initial population of GA. As genetic operators, the elitist strategy in enlarged sampling space developed by Gen and Chang (1997), a new two-point crossover operator, and a new random mutation operator are used for selection, crossover and mutation, respectively. For hybrid concept of GA, an iterative hill climbing method (IHCM) developed by Michalewicz (1994) is inserted into HGA search loop. The IHCM is one of local search techniques and precisely explores the space converged by GA search. The RLNCC is composed of collection centers, remanufacturing centers, redistribution centers, and secondary markets in reverse logistics networks. Of the centers and secondary markets, only one collection center, remanufacturing center, redistribution center, and secondary market should be opened in reverse logistics networks. Some assumptions are considered for effectively implementing the RLNCC The RLNCC is represented by a mixed integer programming (MIP) model using indexes, parameters and decision variables. The objective function of the MIP model is to minimize the total cost which is consisted of transportation cost, fixed cost, and handling cost. The transportation cost is obtained by transporting the returned products between each centers and secondary markets. The fixed cost is calculated by opening or closing decision at each center and secondary markets. That is, if there are three collection centers (the opening costs of collection center 1 2, and 3 are 10.5, 12.1, 8.9, respectively), and the collection center 1 is opened and the remainders are all closed, then the fixed cost is 10.5. The handling cost means the cost of treating the products returned from customers at each center and secondary markets which are opened at each RLNCC stage. The RLNCC is solved by the proposed HGA approach. In numerical experiment, the proposed HGA and a conventional competing approach is compared with each other using various measures of performance. For the conventional competing approach, the GA approach by Yun (2013) is used. The GA approach has not any local search technique such as the IHCM proposed the HGA approach. As measures of performance, CPU time, optimal solution, and optimal setting are used. Two types of the RLNCC with different numbers of customers, collection centers, remanufacturing centers, redistribution centers and secondary markets are presented for comparing the performances of the HGA and GA approaches. The MIP models using the two types of the RLNCC are programmed by Visual Basic Version 6.0, and the computer implementing environment is the IBM compatible PC with 3.06Ghz CPU speed and 1GB RAM on Windows XP. The parameters used in the HGA and GA approaches are that the total number of generations is 10,000, population size 20, crossover rate 0.5, mutation rate 0.1, and the search range for the IHCM is 2.0. Total 20 iterations are made for eliminating the randomness of the searches of the HGA and GA approaches. With performance comparisons, network representations by opening/closing decision, and convergence processes using two types of the RLNCCs, the experimental result shows that the HGA has significantly better performance in terms of the optimal solution than the GA, though the GA is slightly quicker than the HGA in terms of the CPU time. Finally, it has been proved that the proposed HGA approach is more efficient than conventional GA approach in two types of the RLNCC since the former has a GA search process as well as a local search process for additional search scheme, while the latter has a GA search process alone. For a future study, much more large-sized RLNCCs will be tested for robustness of our approach.

Measuring Consumer-Brand Relationship Quality (소비자-브랜드 관계 품질 측정에 관한 연구)

  • Kang, Myung-Soo;Kim, Byoung-Jai;Shin, Jong-Chil
    • Journal of Global Scholars of Marketing Science
    • /
    • v.17 no.2
    • /
    • pp.111-131
    • /
    • 2007
  • As a brand becomes a core asset in creating a corporation's value, brand marketing has become one of core strategies that corporations pursue. Recently, for customer relationship management, possession and consumption of goods were centered on brand for the management. Thus, management related to this matter was developed. The main reason of the increased interest on the relationship between the brand and the consumer is due to acquisition of individual consumers and development of relationship with those consumers. Along with the development of relationship, a corporation is able to establish long-term relationships. This has become a competitive advantage for the corporation. All of these processes became the strategic assets of corporations. The importance and the increase of interest of a brand have also become a big issue academically. Brand equity, brand extension, brand identity, brand relationship, and brand community are the results derived from the interest of a brand. More specifically, in marketing, the study of brands has been led to the study of factors related to building of powerful brands and the process of building the brand. Recently, studies concentrated primarily on the consumer-brand relationship. The reason is that brand loyalty can not explain the dynamic quality aspects of loyalty, the consumer-brand relationship building process, and especially interactions between the brands and the consumers. In the studies of consumer-brand relationship, a brand is not just limited to possession or consumption objectives, but rather conceptualized as partners. Most of the studies from the past concentrated on the results of qualitative analysis of consumer-brand relationship to show the depth and width of the performance of consumer-brand relationship. Studies in Korea have been the same. Recently, studies of consumer-brand relationship started to concentrate on quantitative analysis rather than qualitative analysis or even go further with quantitative analysis to show effecting factors of consumer-brand relationship. Studies of new quantitative approaches show the possibilities of using the results as a new concept of viewing consumer-brand relationship and possibilities of applying these new concepts on marketing. Studies of consumer-brand relationship with quantitative approach already exist, but none of them include sub-dimensions of consumer-brand relationship, which presents theoretical proofs for measurement. In other words, most studies add up or average out the sub-dimensions of consumer-brand relationship. However, to do these kind of studies, precondition of sub-dimensions being in identical constructs is necessary. Therefore, most of the studies from the past do not meet conditions of sub-dimensions being as one dimension construct. From this, we question the validity of past studies and their limits. The main purpose of this paper is to overcome the limits shown from the past studies by practical use of previous studies on sub-dimensions in a one-dimensional construct (Naver & Slater, 1990; Cronin & Taylor, 1992; Chang & Chen, 1998). In this study, two arbitrary groups were classified to evaluate reliability of the measurements and reliability analyses were pursued on each group. For convergent validity, correlations, Cronbach's, one-factor solution exploratory analysis were used. For discriminant validity correlation of consumer-brand relationship was compared with that of an involvement, which is a similar concept with consumer-based relationship. It also indicated dependent correlations by Cohen and Cohen (1975, p.35) and results showed that it was different constructs from 6 sub-dimensions of consumer-brand relationship. Through the results of studies mentioned above, we were able to finalize that sub-dimensions of consumer-brand relationship can viewed from one-dimensional constructs. This means that the one-dimensional construct of consumer-brand relationship can be viewed with reliability and validity. The result of this research is theoretically meaningful in that it assumes consumer-brand relationship in a one-dimensional construct and provides the basis of methodologies which are previously preformed. It is thought that this research also provides the possibility of new research on consumer-brand relationship in that it gives root to the fact that it is possible to manipulate one-dimensional constructs consisting of consumer-brand relationship. In the case of previous research on consumer-brand relationship, consumer-brand relationship is classified into several types on the basis of components consisting of consumer-brand relationship and a number of studies have been performed with priority given to the types. However, as we can possibly manipulate a one-dimensional construct through this research, it is expected that various studies which make the level or strength of consumer-brand relationship practical application of construct will be performed, and not research focused on separate types of consumer-brand relationship. Additionally, we have the theoretical basis of probability in which to manipulate the consumer-brand relationship with one-dimensional constructs. It is anticipated that studies using this construct, which is consumer-brand relationship, practical use of dependent variables, parameters, mediators, and so on, will be performed.

  • PDF

Export Control System based on Case Based Reasoning: Design and Evaluation (사례 기반 지능형 수출통제 시스템 : 설계와 평가)

  • Hong, Woneui;Kim, Uihyun;Cho, Sinhee;Kim, Sansung;Yi, Mun Yong;Shin, Donghoon
    • Journal of Intelligence and Information Systems
    • /
    • v.20 no.3
    • /
    • pp.109-131
    • /
    • 2014
  • As the demand of nuclear power plant equipment is continuously growing worldwide, the importance of handling nuclear strategic materials is also increasing. While the number of cases submitted for the exports of nuclear-power commodity and technology is dramatically increasing, preadjudication (or prescreening to be simple) of strategic materials has been done so far by experts of a long-time experience and extensive field knowledge. However, there is severe shortage of experts in this domain, not to mention that it takes a long time to develop an expert. Because human experts must manually evaluate all the documents submitted for export permission, the current practice of nuclear material export is neither time-efficient nor cost-effective. Toward alleviating the problem of relying on costly human experts only, our research proposes a new system designed to help field experts make their decisions more effectively and efficiently. The proposed system is built upon case-based reasoning, which in essence extracts key features from the existing cases, compares the features with the features of a new case, and derives a solution for the new case by referencing similar cases and their solutions. Our research proposes a framework of case-based reasoning system, designs a case-based reasoning system for the control of nuclear material exports, and evaluates the performance of alternative keyword extraction methods (full automatic, full manual, and semi-automatic). A keyword extraction method is an essential component of the case-based reasoning system as it is used to extract key features of the cases. The full automatic method was conducted using TF-IDF, which is a widely used de facto standard method for representative keyword extraction in text mining. TF (Term Frequency) is based on the frequency count of the term within a document, showing how important the term is within a document while IDF (Inverted Document Frequency) is based on the infrequency of the term within a document set, showing how uniquely the term represents the document. The results show that the semi-automatic approach, which is based on the collaboration of machine and human, is the most effective solution regardless of whether the human is a field expert or a student who majors in nuclear engineering. Moreover, we propose a new approach of computing nuclear document similarity along with a new framework of document analysis. The proposed algorithm of nuclear document similarity considers both document-to-document similarity (${\alpha}$) and document-to-nuclear system similarity (${\beta}$), in order to derive the final score (${\gamma}$) for the decision of whether the presented case is of strategic material or not. The final score (${\gamma}$) represents a document similarity between the past cases and the new case. The score is induced by not only exploiting conventional TF-IDF, but utilizing a nuclear system similarity score, which takes the context of nuclear system domain into account. Finally, the system retrieves top-3 documents stored in the case base that are considered as the most similar cases with regard to the new case, and provides them with the degree of credibility. With this final score and the credibility score, it becomes easier for a user to see which documents in the case base are more worthy of looking up so that the user can make a proper decision with relatively lower cost. The evaluation of the system has been conducted by developing a prototype and testing with field data. The system workflows and outcomes have been verified by the field experts. This research is expected to contribute the growth of knowledge service industry by proposing a new system that can effectively reduce the burden of relying on costly human experts for the export control of nuclear materials and that can be considered as a meaningful example of knowledge service application.

Evaluating efficiency of application the skin flash for left breast IMRT. (왼쪽 유방암 세기변조방사선 치료시 Skin Flash 적용에 대한 유용성 평가)

  • Lim, Kyoung Dal;Seo, Seok Jin;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.30 no.1_2
    • /
    • pp.49-63
    • /
    • 2018
  • Purpose : The purpose of this study is investigating the changes of treatment plan and comparing skin dose with or without the skin flash. To investigate optimal applications of the skin flash, the changes of skin dose of each plans by various thicknesses of skin flash were measured and analyzed also. Methods and Material : Anthropomorphic phantom was scanned by CT for this study. The 2 fields hybrid IMRT and the 6 fields static IMRT were generated from the Eclipse (ver. 13.7.16, Varian, USA) RTP system. Additional plans were generated from each IMRT plans by changing skin flash thickness to 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm and 2.5 cm. MU and maximum doses were measured also. The treatment equipment was 6MV of VitalBeam (Varian Medical System, USA). Measuring device was a metal oxide semiconductor field-effect transistor(MOSFET). Measuring points of skin doses are upper (1), middle (2) and lower (3) positions from center of the left breast of the phantom. Other points of skin doses, artificially moved to medial and lateral sides by 0.5 cm, were also measured. Results : The reference value of 2F-hIMRT was 206.7 cGy at 1, 186.7 cGy at 2, and 222 cGy at 3, and reference values of 6F-sIMRT were measured at 192 cGy at 1, 213 cGy at 2, and 215 cGy at 3. In comparison with these reference values, the first measurement point in 2F-hIMRT was 261.3 cGy with a skin flash 2.0 cm and 2.5 cm, and the highest dose difference was 26.1 %diff. and 5.6 %diff, respectively. The third measurement point was 245.3 cGy and 10.5 %diff at the skin flash 2.5 cm. In the 6F-sIMRT, the highest dose difference was observed at 216.3 cGy and 12.7 %diff. when applying the skin flash 2.0 cm for the first measurement point and the dose difference was the largest at the application point of 2.0 cm, not the skin flash 2.5 cm for each measurement point. In cases of medial 0.5 cm shift points of 2F-hIMRT and 6F-sIMRT without skin flash, the measured value was -75.2 %diff. and -70.1 %diff. at 2F, At -14.8, -12.5, and -21.0 %diff. at the 1st, 2nd and 3rd measurement points, respectively. Generally, both treatment plans showed an increase in total MU, maximum dose and %diff as skin flash thickness increased, except for some results. The difference of skin dose using 0.5 cm thickness of skin flash was lowest lesser than 20 % in every conditions. Conclusion : Minimizing the thickness of skin flash by 0.5 cm is considered most ideal because it makes it possible to keep down MUs and lowering maximum doses. In addition, It was found that MUs, maximum doses and differences of skin doses did not increase infinitely as skin flash thickness increase by. If the error margin caused by PTV or other factors is lesser than 1.0 cm, It is considered that there will be many advantages in with the skin flash technique comparing without it.

  • PDF

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
    • /
    • v.38 no.1
    • /
    • pp.112-160
    • /
    • 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.

The Aspects of Change of Sijo (시조의 변이 양상)

  • Kang Myeoung-Hye
    • Sijohaknonchong
    • /
    • v.24
    • /
    • pp.5-46
    • /
    • 2006
  • Korean verse has flexibly changed its form and contents according to the historical background of the times. This fact arouses reader sympathy because it has reflected ideas, historical aspects and realities of the times. However, korean verse has kept its own characteristics in some ways, allowing it to exist today. It holds its form as 3 verses of three by three or four meter and three letters of the last of three verses. It makes every different version which has specific aspects of each times in the same 'sijo' area. 'Sijo' in Korean poems, is the first form that has been changed from formal to private functionally. As a result of that common verses in the Goryeo to Joseon eras were going with the stream of the times. Verse was the plate for justice so that there was no double meaning, symbols, or technical sentences. It had to show the idea of Myungchundo Jwonginryun. The theme was commonly fitted within certain areas. such as blessings, fidelity, devotion, etc. Around the end of the Joseon era, there was activation of private verses - a form of sijo with no restrictions on the length of the first two verses. Some ideas had been changed because Sarimpa gained power, domestic conflict, and the introduction of practical science. These things had an effect on the form of Sijo. After all, it shows the ideas of collapsing feudalism, resistance of confucian ideas, equality of the sexes, and opposition to the group who rule the government. Thus Sasul Sijo seems to have the tendency of resistance to reality. It was a specialty of realism poetry It explained our life in detail and reflected real life by being an intermediary of realism. This met and represented the demand of a reader's expectations. After 1905, there was new form of sijo that is very different, in form and content, from the previous versions. It was even different in areas of what people accepted. They started to think sijo was not the form of lyrical verse that is once was. It became a 'record of reading'. The form changed to 'hung or huhung' that satirized the times and the ending of a word in the last verse. Although this form could deliver the tension in statement, it was too iu from the original form. Therefore, it didn't last long, and its position got smaller because of the free verse that had western influence and was emerging in the times. In the middle of 1920, there was a movement of Sijo revival. It was lead by Choinamsun. He wrote poems and Sijo which were effected by western ideas in his early works. Although he worked with that, he took the lead in the movement of Sijo revival. He published the collection of Sijo $\ulcorner$Baekpalbunnwoi$\lrcorner$ that has one major theme-patriotic sentiment. He thought an ancient poem was a part of racial characteristics so that he expressed the main theme which represented the times and situations of his era. Modern Sijo is difficult. Sijo has to have modern and Korean verse characteristics at the same time. If it considers a modern aspect too much, it could not be distinguished from sijo and free verse. If it overly leans toward Sijo. it would seem to be too conservative which it then could be said to have no real charm of a poem. In spite of these problems, it is written constantly, because it has its own specialty. It has been focused on some works because they reflect awareness of modern times, the democratic idea, and realism. Overall, the authors of Modern Sijo express various themes by using different forms. The more what we can guess in this work, Sijo will exist permanently because of its flexibility. Furthermore, one special characteristic-flexibility of the korean verse will make it last forever and it will be a genre in Korean poetry.

  • PDF