• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.439-449
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• 2018

Many potential sources of bias are used in several steps of the radar-rainfall estimation process because the hydrological and meteorological radars measure the rainfall amount indirectly. Previous studies on radar-rainfall uncertainties were performed to reduce the uncertainty of each step by using bias correction methods in the quantitative radar-rainfall estimation process. However, these studies do not provide comprehensive uncertainty for the entire process and the relative ratios of uncertainty between each step. Consequently, in this study, a suitable approach is proposed that can quantify the uncertainties at each step of the quantitative radar-rainfall estimation process and show the uncertainty propagation through the entire process. First, it is proposed that, in the suitable approach, the new concept can present the initial and final uncertainties, variation of the uncertainty as well as the relative ratio of uncertainty at each step. Second, the Maximum Entropy Method (MEM) and Uncertainty Delta Method (UDM) were applied to quantify the uncertainty and analyze the uncertainty propagation for the entire process. Third, for the uncertainty quantification of radar-rainfall estimation at each step, two quality control algorithms, two radar-rainfall estimation relations, and two bias correction methods as post-processing through the radar-rainfall estimation process in 18 rainfall cases in 2012. For the proposed approach, in the MEM results, the final uncertainty (from post-processing bias correction method step: ME = 3.81) was smaller than the initial uncertainty (from quality control step: ME = 4.28) and, in the UDM results, the initial uncertainty (UDM = 5.33) was greater than the final uncertainty (UDM = 4.75). However uncertainty of the radar-rainfall estimation step was greater because of the use of an unsuitable relation. Furthermore, it was also determined in this study that selecting the appropriate method for each stage would gradually reduce the uncertainty at each step. Therefore, the results indicate that this new approach can significantly quantify uncertainty in the radar-rainfall estimation process and contribute to more accurate estimates of radar rainfall.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.272-280
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• 2013

This study aims to develop a standard diagnostic table for management and administration that oak mushroom cultivators of forestry households can utilize. By diagnosing their current level of management with the table, the cultivators themselves will be able to grasp and address their operational challenges better. The table is composed of; questions on the status of forestry households; columns for a series of management performance indices, and; questionnaire with 4 categories and 20 subcategories to check the current level of management and administration by the households. In order to prepare the standard diagnostic table for oak mushroom management, 196 forestry households throughout 10 areas - Cheong-yang, Gong-ju, Bu-yeo and Seocheon in Chungcheongnam-do, Mun-kyung and Ye-cheon in Gyeongsangbuk-do, Jin-an in Jeollabuk-do, Jangheung and Jang-seong in Jeollanam-do, and Jeju Islands - were interviewed with and a total of 190 questionnaires were acquired and made use of in the result analysis. Then, the score on management level of each forestry household was determined in the way of aggregating scores from each subcategory. The overall average score of every household was calculated at 62.2 point with more than half of the respondents, 54.7%, belonging to the range of 60 to 80. When considered by regional groups, the average score of Jin-an was the lowest with 57.6 point while that of Jang-seong was the highest with 69.6 point. In case of the 'cultivation management' category, there were a lot of cultivators who expressed a negative awareness of the term 'pest control' because they had a tendency to think the term in connection with 'herbicides or pesticides'. So it is inevitable to adapt and modify existing groups and grades to make sure that the cultivators can make a right choice without confusing the concept 'pest control' with 'herbicides or pesticides'. Meanwhile, the average scores of 'management and administration' categories were mostly low. It was remarkable in these categories that forestry households in Jeolla province, which had remained in lower ranks in the other three categories, recorded higher scores than those in Chungcheong province, boasting a relatively high level of management and administration.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.893-910
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• 2013

The purpose of this study was to identify changes in mental models of students in the elementary school about causes of seasonal changes. During a total of eight sessions, eight sixth graders were asked to describe the causes of seasonal changes through pictures, writing and thinking aloud by using microgenetic research methods, and the changes in mental models were examined. When the research was conducted, linguistic and behavioral factors and contents of interviews of participants were recorded on video. Moreover, a variety of materials such as field observation chart were written by a researcher and mental models records were written by a student. The protocol was written by integration of collected results, and it was repeated to read and was inductively categorized. The results of this study were as follows: First, participants' mental models about causes of seasonal changes were changed in various paths within and across sessions. Participants' mental models that had been more changed in various ways were closer to the scientific model. In addition, like rotation and revolution, students who correctly established the preconceptions related to seasonal changes formed the mental models consistent with scientific concept based on new information. On the other hand, students who did not correctly establish the preconceptions did not deviate from non-scientific mental models. Second, prior knowledge, experience and information which participants held in advance, accuracy of prior knowledge, resolution of inconsistency between new knowledge and existing mental models, activation of mental models through operation of models and drawing an picture affected the changes of mental models. Teachers should provide to learners with sufficient experience which can be configured to various mental models in order to form the scientific concepts. And they need to let learners feel the doubt and resolve it through presentation of new teaching material which is inconsistent with the existing mental models.

• Journal of Korean Home Economics Education Association
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• v.19 no.4
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• pp.233-245
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• 2007

The purpose of this study is to investigate the appropriate way of essay writing education which helps the learners perceive and express a stream of knowledge through Home Economics education curriculum by themselves. While one-way type, which teachers just give instructions to students and students just learn from them, has dominated the education, new education focuses on interactive and reciprocal way in thinking and researching together. This new stream requires appropriate and various education method as well as the new concept of education curriculum. This study applies the curriculum of the German practical philosophy that recently has been a debated topic in Home Economics education. The purpose of the curriculum pursuits improving students' practical and critical thinking competence and essay writing is the center of it. In the curriculum learners write essays by asking and answering the questions through seven areas which students can experience based on three angles such as individual, social, and idealogical viewpoints. In this process learners don't remain in the individual angles and are able to be trained as intellectuals who can lead the social and cultural change as well as the individual growth by getting an insight into the idealogical angles. The Germany curriculum what is mentioned in advance presents one possibility that essay education can be introduced in Home Economics education that has accessed the education process by the practical inference based on the practical philosophy. That is, Home Economics education shares the context with essay education whose purpose is the intellect enlightenment because the former is the curriculum to make students build the abilities to access in many-sided angles not just one point, to deal with problems wisely, and to deduce the solutions. Therefore, students are expected to participate in the class dynamically by being satisfied intellectually abreast of practical essay education that helps learners read the stream of knowledge through Home Economics education. In this manner the category of Home Economics education will enlarge by making efforts to diversify the education methodology not staying only one method.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.1-19
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• 2010

In offline environment, unlike traditional advertising model through TV, newspaper, and radio, online advertising model draws instantaneous responses from potential consumers and it is convenient to assess. This kind of characteristics of Internet advertising model has driven the growth of advertising model among various Internet business models. There are, conventionally classified, CPM (Cost Per Mile), CPC (Cost Per Click), and CPS (Cost Per Sales) models as Internet advertising expenditure model. These can be examined in manners regarding risks that stakeholders should stand and degree of responsibility. CPM model that is based on number of advertisement exposure is mechanically exposed to users but not actually recognized by users resulting in risk of wasted expenditure by advertisers without any advertising effect. While on aspect of media, CPS model that is based on conversion action is the most risky model because of the conversion action such as product purchase is determined by capability of advertisers not that of media. In this regard, while there are issue of CPM and CPS models disadvantageously affecting only one side of Internet advertising business model value network, CPC model has been evaluated as reasonable both to advertisers and media, and occupied the largest segment of Internet advertising market. However, CPC model also can cause fraudulent behavior such as click fraud because of the competition or dishonest amount of advertising expenditure. On the user aspect, unintentionally accessed advertisements can lead to more inappropriate expenditure from advertisers. In this paper, we suggest "CPCD"(Cost Per Coupon Download) model. This goes beyond simple clicking of advertisements and advertising expenditure is exerted when users download a coupon from advertisers, which is a concept in between CPC and CPS models. To achieve the purpose, we describe the scenario of advertiser perspective, processes, participants and their benefits of CPCD model. Especially, we suggest the new value in online coupon; "possibility of storage" and "complement for delivery to the target group". We also analyze the working condition for advertiser by a comparison of CPC and CPCD models through advertising expenditure simulation. The result of simulation implies that the CPCD model suits more properly to advertisers with medium-low price products rather than that of high priced goods. This denotes that since most of advertisers in CPC model are dealing with medium-low priced products, the result is very interesting. At last, we contemplate applicability of CPCD model in ubiquitous environment.

• Management & Information Systems Review
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• v.36 no.5
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• pp.45-60
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• 2017

This study aims to elucidate the key improvements through the current state of customer support for smart home services based on the Internet of things and the evaluation of user's usage. Smart home services typically provide a wide range of value in terms of security, safety, manageability (electricity and water use), convenience, and remote management accessibility. In this study, we analyzed the current state of smart home service based on Internet of Samsung, SKT and LG U + companies in Korea. However, since LG U+ is the only company providing user reviews, there is a limit to generalization, but we are trying to figure out whether the customer value is conveyed properly or not, and in which part the customer support is focused to support the service. As a result of analyzing the results of the study, we found that the smart home service is commercialized and marketed in various forms. However, it is questionable whether the technological level and user satisfaction level are sufficiently satisfied. The results of this study are as follows. First, although each company provides usage guidance, they still ask many questions about joining products and using products. Second, there are many defects in the product itself, and it is found that the companies are not satisfied with the overall response. Third, the three companies are focusing on switches, outlets, sensors, and lamps. This is an individual intelligent product rather than an interlocking or linking level, and it can be seen that there are many parts that are not compatible with the concept of the original Internet of things. In conclusion, this study shows that there are still many areas to improve on the level of customer service provision of smart home service, in particular, the ease of use is low and the quality of products is not reliable. We would like to present the improvement of this in detail through this study and reflect the companies that provide it and the service providers.

• Management & Information Systems Review
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• v.36 no.5
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• pp.121-149
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• 2017

This study looks into individual entrepreneurship engaged in an enterprise; the effect of creative efficacy and internal and external networks on organizational commitment based on the previous studies. The hypothesis, the internal and external networks constructed in social context by individuals in the relationship between individual entrepreneurship and organizational commitment; and mediating effect through creative efficacy obtained by the previous experience can be in existence, is to be confirmed through an empirical study. The analysis data is collected from 244 of currently working employees via a survey. The determination of employee-oriented study is summarized as follows: first, the promotion of employee's individual entrepreneurship is significant as well as of the leader for the result of organizational commitment, because there are positive effects between the individual entrepreneurship and organizational commitment. Second, the internal and external networks owned by individuals affect one's own outcome as the internal and external networks of enterprise mediate the relationship between individual entrepreneurship and organizational commitment. Third, it is confirmed that the confidence in individual creativity is an essential factor as creative efficacy exhibits a mediating effect in relationship between individual entrepreneurship and organizational commitment. Particularly, it is verified that an enterprise is in need to expand education or programs not only for networks leading to an outcome but also for creativity improvement of affiliated individuals from the fact that creative efficacy, a hybridized concept of creativity and self-efficacy studied in the previous research, mediates the relationship between individual entrepreneurship and an outcome. In the conclusion, additional implications are offered; the thresholds and frameworks for the study are discussed.

• The Journal of Society for e-Business Studies
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• v.19 no.4
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• pp.231-249
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• 2014

We define $21^{st}$ century as an amalgamation of globalization and localization, or Glocalization. Additionally, due to the increasing supply of smart phones and wide usage of social networking services, the ability to utilize such global and regional information has increased a coperation's competitiveness in its market, and even the business models have evolved from the conventional "production and distribution" to E-commerce, through which either a direct or a non-direct transaction is possible. My hypothesis is that the ability to adapt to this trend is possible through transfer of learning, and consequently, this will have an impact on company's performance. Thus, this thesis analyzes the mid- to the long-term impact of such ability and environmental factors on the performance and technology innovation of Korean companies in China. Ultimately, this study intends to engender a basic foundation for a corporation's management strategy in China. Finally this research focuses on those Korean companies in China only and on the proof of influential factors' impact on technological innovation and technological innovation's impact on those corporations' future performances. Section I is an abstract and section II, the case examines the uniqueness and current status of Korean companies in China identifies the concept and the definition of influential factors such as education-orientation, technological innovation, and performance, and then scrutinizes each factors through a closer look at their past researches. Section III explains the thesis model, the survey's method and target, the thesis, variable factors, the content, and the method of analysis. In section IV, the thesis is proved based on the outcome of the survey. The result in Section V highlights the high comprehension of technological innovation: both education-orientation and technological innovation prove to have a positive (+) correlation with the performance. The vision on education orientation proves to have a positive (+) influence on technological innovation. The vision on education-orientation and technological innovation prove to have a positive (+) influence individually on company's performance.

• Journal of Korean Home Economics Education Association
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• v.25 no.2
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• pp.103-128
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• 2013

The purpose of this study was to develop a school violence prevention program featuring the Practical Action Teaching Model(hereafter, PATM) for middle school students to prevent school violence by Home Economics Education. To accomplish this purpose, the processes of analysis, design, development, and evaluation based on ADDIE were conducted. The validity of the program was evaluated twice by Home Economics education experts(36 experts for the first group and 10 experts for the second group) and the contents of the program were modified according to the comments from the evaluators. The school violence prevention program in Home Economics classes consisted of 5 topics such as changing perception on school violence, enhancing self-esteem, relating with others, practicing consideration and sharing, and strengthening the will of preventing school violence. Twenty-four units were developed with 7 practical problems(What should I do to make friends to help with each other?, What should I do to establish positive self-concept?, What should I do to communicate to build good relationship?, What should I do to solve the conflicts peacefully?, What should I do to practice consideration and sharing in food consumption?, and What should I do to practice consideration and sharing in clothing?) in 5 topic areas. Teaching-learning plans included four steps such as problem perception, practical reasoning, action, and evaluation that comprise PATM to solve the practical problems. Every step of the teaching-learning plan consisted of questions for practical reasoning and activity assignments. Materials for students and teachers were developed. Materials for students comprised 80 pieces in total including student activity, reading, movie, and clips to make students enhance understanding and interest. Materials for teachers comprised 35 pieces in total such as rationales, newspaper articles, and movies that make teachers that lesson teaching loads and were helpful for teachers. The PATM was incorporated into developing the program and a Likert-scale was used to assess usefulness, applicability, appropriateness, fidelity, substantiality, and validity of this program. This program gained more than 4.00 on a 1-5 Likert scale. This result indicated that program is expected to be effective and useful to school violence prevention.

• KDI Journal of Economic Policy
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• v.12 no.2
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• pp.95-120
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• 1990

The underpricing of new shares of a firm that are offered to the public for the first time (initial offerings) is well known and has puzzled financial economists for a long time since it seems at odds with the optimal behavior of the owners of issuing firms. Past attempts by financial economists to explain this phenomenon have not been successful in the sense that the explanations given by them are either inconsistent with the equilibrium theory or implausible. Approaches by such authors as Welch or Allen and Faulhaber are no exceptions. In this paper, we develop a signalling model of capital investment to explain the underpricing phenomenon and also analyze the efficiency of investment. The model focuses on the information asymmetry between the owners of issuing firms and general investors. We consider a firm that has been owned and operated by a single owner and that has a profitable project but has no capital to develop it. The profit from the project depends on the capital invested in the project as well as a profitability parameter. The model also assumes that the financial market is represented by a single investor who maximizes the expected wealth. The owner has superior information as to the value of the firm to investors in the sense that it knows the true value of the parameter while investors have only a probability distribution about the parameter. The owner offers the representative investor a fraction of the ownership of the firm in return for a certain amount of investment in the firm. This offer condition is equivalent to the usual offer condition consisting of the number of issues to sell and the unit price of a share. Thus, the model is a signalling game. Using Kreps' criterion as the solution concept, we obtained an essentially unique separating equilibrium offer condition. Analysis of this separating equilibrium shows that the owner of the firm with high profitability chooses an offer condition that raises an amount of capital that is short of the amount that maximizes the potential profit from the project. It also reveals that the fraction of the ownership of the firm that the representative investor receives from the owner of the highly profitable firm in return for its investment has a value that exceeds the investment. In other words, the initial offering in the model is underpriced when the profitability of the firm is high. The source of underpricing and underinvestment is the signalling activity by the owner of the highly profitable firm who attempts to convince investors that his firm has a highly profitable project by choosing an offer condition that cannot be imitated by the owner of a firm with low profitability. Thus, we obtained two main results. First, underpricing is a result of a signalling activity by the owner of a firm with high profitability when there exists information asymmetry between the owner of the issuing firm and investors. Second, such information asymmetry also leads to underinvestment in a highly profitable project. Those results clearly show the underpricing entails underinvestment and that information asymmetry leads to a social cost as well as a private cost. The above results are quite general in the sense that they are based upon a neoclassical profit function and full rationality of economic agents. We believe that the results of this paper can be used as a basis for further research on the capital investment process. For instance, one can view the results of this paper as a subgame equilibrium in a larger game in which a firm chooses among diverse ways to raise capital. In addition, the method used in this paper can be used in analyzing a wide range of problems arising from information asymmetry that the Korean financial market faces.