• Journal of Agricultural Extension & Community Development
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• v.17 no.1
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• pp.25-43
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• 2010

The objectives of this study are to estimate the number of employed persons related to agriculture in agribusiness, to determine any factors affecting changes in employed persons, based on the Input-Output Tables in 1995, 2000, and 2005. The number of employed persons related to Crops in the input industry of agriculture was 184,076 in 1995, 186,616 in 2000, and 193,394 in 2005. The sectors with higher number of employed persons were in; Agriculture, forestry and fishing related services, Wholesale and retail trade, Fertilizers and agricultural chemicals, and Forest products, etc. The number of employed persons related to Animals in the input industry of agriculture was 46,6166 in 1995, 28,886 in 2000, and 35,714 in 2005. The sectors with higher number of employed persons were in; Wholesale and retail trade, Prepared livestock feeds, Agriculture, forestry and fishing related services, and Forest products, etc. The number of employed persons related to Crops in post-farm gate industries was 184,076 in 1995, 186,616 in 2000, and 193,394 in 2005. The sectors with higher number of employed persons were in; Accommodation and food services, Other food products, Wholesale and retail trade, and Polished grains, flour and milled cereals, etc. The number of employed persons related to Animals in the post-farm gate industries was 184,076 in 1995, 186,616 in 2000, and 193,394 in 2005. The sectors with higher number of employed persons were in; Meat and dairy products, Wholesale and retail trade, Accommodation and food services, and Land transport, etc. In 2005, the number of employed persons related to agriculture in agribusiness per 1,000 employed persons in agriculture was 211, in the input industries in agriculture it was 53, and in the post-farm gate industries it was 158.gribusiness.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.50-58
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• 2013

In this paper, parallel decimal fixed-point multiplier which uses the limited range of Singed-Digit number encoding and the reduction step is proposed. The partial products are generated without carry propagation delay by encoding a multiplicand and a multiplier to the limited range of SD number. With the limited range of SD number, the proposed multiplier can improve the partial product reduction step by increasing the number of possible operands for multi-operand SD addition. In order to estimate the proposed parallel decimal multiplier, synthesis is implemented using Design Compiler with SMIC 180nm CMOS technology library. Synthesis results show that the delay of proposed parallel decimal multiplier is reduced by 4.3% and the area by 5.3%, compared to the existing SD parallel decimal multiplier. Despite of the slightly increased delay and area of partial product generation step, the total delay and area are reduced since the partial product reduction step takes the most proportion.

• The Mathematical Education
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• v.51 no.1
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• pp.1-19
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• 2012

In this study, contents of 'the 2007 revised curriculum handbook' and 16 kinds of mathematics textbooks were analyzed first. The purpose of this study is to examine the understanding state of students at general high schools by making questionnaires to survey the understanding state on contents of chapter of complex number based on above analysis. Results of research can be summarized as follows. First, the content of chapter of complex number in textbook was not logically organized. In the introduction of imaginary number unit, two kinds of marks were presented without any reason and it has led to two kinds of notation of negative square root. There was no explanation of difference between delimiter symbol and operator symbol at all. The concepts were presented as definition without logical explanations. Second, students who learned with textbook in which problems were pointed out above did not have concept of complex number for granted, and recognized it as expansion of operation of set of real numbers. It meant that they were confused of operation of complex numbers and did not form the image about number system itself of complex number. Implications from this study can be obtained as follows. First, as we came over to the 7th curriculum, the contents of chapter of complex number were too abbreviated to have the logical configuration of chapter in order to remove the burden for learning. Therefore, the quantitative expansion and logical configuration fit to the level for high school students corresponding to the formal operating stage are required for correct configuration of contents of chapter. Second, teachers realize the importance of chapter of complex number and reconstruct the contents of chapter to let students think conceptually and logically.

• Archives of Plastic Surgery
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• v.38 no.3
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• pp.263-272
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• 2011

Purpose: The human face is the most exposed part of the body, and in patients with simple or complex trauma from traffic accidents, industrial calamities, sports injuries, human assaults, and daily accidents, facial trauma occupies an important portion. The etiology of facial trauma vary on a society's economic, cultural, and environmental status. Methods: Regarding patients who were admitted from between the years 2000 to 2009 at the Hanyang University hospital, the authors studied how the changes in the economic status in the past 10 years of our country influences the incidence of facial bone fractures. Results: In this study, 1) The unemployment rate showed a strong negative relationship with the total number of inpatients with facial bone fractures, the number of male patients, the number of female patients, the number of patients with facial bone fractures caused by fall down, the number of patients who were admitted for shorter than 7 days, and the number of the facial bone fracture patients with their age in the twenties. 2) The consumer price index showed a strong positive relationship with the number of female patients, the number of patients who were admitted for shorter than 7 days, and the number of the facial bone fracture patients with their age in the teens and fifties. Conclusion: Looking at the results of correlation analysis and multiple regression analysis with economic indicators, the unemployment rate showed negative influence to the total number of inpatients with facial bone fractures, and the number of inpatients with facial bone fractures caused by fall down, with statistical significance.

• Journal of Korean Society for Quality Management
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• v.48 no.3
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• pp.493-510
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• 2020

Purpose: As of July 31, there were 14,336 confirmed cases of COVID-19 in South Korea, including 301 deaths. Since the daily confirmed number of cases hit 909 on February 29, the spread of the disease had gradually decreased due to the active implementation of preventive control interventions, and the daily confirmed number had finally recorded a single digit on April 19. Since May, however, the disease has re-emerged and retaining after June. In order to eradicate the disease, it is necessary to suggest suitable forward preventive strategies by predicting future infectivity of the disease based on the cases so far. Therefore, in this study, we aim to evaluate the transmission potential of the disease in early phases by estimating basic reproduction number and assess the preventive control measures through effective reproduction number. Methods: We used publicly available cases and deaths data regarding COVID-19 in South Korea as of July 31. Using ensemble model integrated stochastic linear birth model and deterministic linear growth model, the basic reproduction number and the effective reproduction number were estimated. Results: Estimated basic reproduction number is 3.1 (95% CI: 3.0-3.2). Effective reproduction number was the highest with 7 on February 15, decreased as of April 20. Since then, the value is gradually increased to more than unity. Conclusion: Preventive policy such as wearing a mask and physical distancing campaigns in the early phase of the outbreak was fairly implemented. However, the infection potential increased due to weakening government policy on May 6. Our results suggest that it seems necessary to implement a stronger policy than the current level.

• Journal of the Korean Society for Library and Information Science
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• v.12
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• pp.7-37
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• 1985

In most of the modern libraries throughout the world, it is popular to adopt the author number which arranges the books or entries in alphabetical order of their author's names within the same ultimate class. However, viewed historically, that was the Western practice never used in the East before. Traditionally chronological order was followed in the East. Book number not only individualizes the books within the same class but also makes it easy for the user to choose and find out the relevant materials. In this respect, chronological book number is decidedly superior to all kinds of book number systems ever have been existed. Especially in these days of rapid obsolescence of documents and with serious problems of storage of documents, the chronological order seems to be the most modern and future-oriented of all other book number systems because it distinguishes clearly new materials from aged materials by the date of publication and controls the stack spaces mechanically and effectively. This writer devised New Chronological Book Numbers adaptable to both the Eastern and Western materials, and the system has been adopted at Yonsei University Library. The features of the system are as follows: (1) It is easy to type the call number in cataloging the Eastern and Western materials. That is because the structure of the chronological number is pure numerical notation by taking the last two figures of the year within twentieth century(e.g. 85 for AD 1985), that is 1900s, and the last three figures of the year from twenty-first century to thirtieth century, that is 2000s. (2) It does not make all classes have chronological number uniformly. Within the classes for individual biographies, genealogies and collections of biography of specific family, books about individual organization, individual literary and artistic works, philosophical works of the famous philosophers, books and its facsmile editions published before 1900, new editions, translations, commentaries, serials, chronological number is assigned to the author number as in the past. (3) It separates the Eastern materials from the Western materials and makes the typing easy in cataloging. That is because the subarrangement within the same chronological book number is made by the accession order which uses 'panjol-ponmun' or the characters of basic syllabic table of Korean alphabet in case of the Eastern materials and Roman alphabet in case of the Western materials.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.2
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• pp.27-39
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• 2006

The Collaborative Filtering (CF) is one of the popular techniques for personalization in e-commerce storefronts. For CF-based recommendation, every customer needs to provide subjective evaluation ratings for some products based on his/her preference. Also, if an e-commerce site recommends a new product, some customers should rate it. However, there is no in-depth investigation on the impacts on recommendation performance of two number of ratings, i.e. the number of ratings of an individual customer and the number of ratings of an item, even though these are important factors to determine performance of CF methods. In this study, using publicly available EachMovie data set, we empirically investigate the relationships between the two number of ratings and the performance of CF. For the purpose, three analyses were executed. The first and second analyses were performed to investigate the relationship between the number of ratings of a particular customer and the recommendation performance of CF. In the third analysis, we investigate the relationship between the number of ratings on a particular item and the recommendation performance of CF. From these experiments, we can find that there are thresholds in terms of the number of ratings below which the recommendation performances increase monotonically. That is, the number of ratings of a customer and the number of ratings on an item are critical to the recommendation performance of CF when the number of ratings is less than the thresholds, but the value of the ratings decreases after the numbers of ratings pass the thresholds. The results of the experiments provide insight to making operational decisions concerning collaborative filtering in practice.

• The Mathematical Education
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• v.47 no.1
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• pp.61-74
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• 2008

The objective of this research is to verify the effect after development and application of a program for advance of number sense. This program presents an opportunity to explore suitable ways for the characteristics of problems by clarifying the meaning of number and operation through various thought processes, not focused on algorithm. To fulfill the objectives I developed the program for advance of number sense, and verify the effect on the improvement of number sense after applying to the developed program. As a result, it was confirm that this program was helpful to the improvement of the students' mathematical aptitude which resulted in a positive change in their attitude.

• Communications of the Korean Mathematical Society
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• v.27 no.4
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• pp.843-849
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• 2012

Let G = (V, E) be a graph with chromatic number ${\chi}(G)$. dominating set D of G is called a chromatic transversal dominating set (ctd-set) if D intersects every color class of every ${\chi}$-partition of G. The minimum cardinality of a ctd-set of G is called the chromatic transversal domination number of G and is denoted by ${\gamma}_{ct}$(G). In this paper we characterize the class of trees, unicyclic graphs and cubic graphs for which the chromatic transversal domination number is equal to the connected domination number.

• Journal of the Korean Mathematical Society
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• v.52 no.4
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• pp.751-763
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• 2015

Let ${\alpha}$ be a positive integer, and let $p_1$, $p_2$ be two distinct prime numbers with $p_1$ < $p_2$. By using elementary methods, we give two equivalent conditions of all even near-perfect numbers in the form $2^{\alpha}p_1p_2$ and $2^{\alpha}p_1^2p_2$, and obtain a lot of new near-perfect numbers which involve some special kinds of prime number pairs. One kind is exactly the new Mersenne conjecture's prime number pair. Another kind has the form $p_1=2^{{\alpha}+1}-1$ and $p_2={\frac{p^2_1+p_1+1}{3}}$, where the former is a Mersenne prime and the latter's behavior is very much like a Fermat number.