• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.121-139
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• 2014

Predicting corporate failure has been an important topic in accounting and finance. The costs associated with bankruptcy are high, so the accuracy of bankruptcy prediction is greatly important for financial institutions. Lots of researchers have dealt with the topic associated with bankruptcy prediction in the past three decades. The current research attempts to use ensemble models for improving the performance of bankruptcy prediction. Ensemble classification is to combine individually trained classifiers in order to gain more accurate prediction than individual models. Ensemble techniques are shown to be very useful for improving the generalization ability of the classifier. Bagging is the most commonly used methods for constructing ensemble classifiers. In bagging, the different training data subsets are randomly drawn with replacement from the original training dataset. Base classifiers are trained on the different bootstrap samples. Instance selection is to select critical instances while deleting and removing irrelevant and harmful instances from the original set. Instance selection and bagging are quite well known in data mining. However, few studies have dealt with the integration of instance selection and bagging. This study proposes an improved bagging ensemble based on instance selection using genetic algorithms (GA) for improving the performance of SVM. GA is an efficient optimization procedure based on the theory of natural selection and evolution. GA uses the idea of survival of the fittest by progressively accepting better solutions to the problems. GA searches by maintaining a population of solutions from which better solutions are created rather than making incremental changes to a single solution to the problem. The initial solution population is generated randomly and evolves into the next generation by genetic operators such as selection, crossover and mutation. The solutions coded by strings are evaluated by the fitness function. The proposed model consists of two phases: GA based Instance Selection and Instance based Bagging. In the first phase, GA is used to select optimal instance subset that is used as input data of bagging model. In this study, the chromosome is encoded as a form of binary string for the instance subset. In this phase, the population size was set to 100 while maximum number of generations was set to 150. We set the crossover rate and mutation rate to 0.7 and 0.1 respectively. We used the prediction accuracy of model as the fitness function of GA. SVM model is trained on training data set using the selected instance subset. The prediction accuracy of SVM model over test data set is used as fitness value in order to avoid overfitting. In the second phase, we used the optimal instance subset selected in the first phase as input data of bagging model. We used SVM model as base classifier for bagging ensemble. The majority voting scheme was used as a combining method in this study. This study applies the proposed model to the bankruptcy prediction problem using a real data set from Korean companies. The research data used in this study contains 1832 externally non-audited firms which filed for bankruptcy (916 cases) and non-bankruptcy (916 cases). Financial ratios categorized as stability, profitability, growth, activity and cash flow were investigated through literature review and basic statistical methods and we selected 8 financial ratios as the final input variables. We separated the whole data into three subsets as training, test and validation data set. In this study, we compared the proposed model with several comparative models including the simple individual SVM model, the simple bagging model and the instance selection based SVM model. The McNemar tests were used to examine whether the proposed model significantly outperforms the other models. The experimental results show that the proposed model outperforms the other models.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.19-47
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• 2015

In this era of knowledge economy, a variety of virtual communities are proliferating for the purpose of knowledge creation and utilization. Since the voluntary contributions of members are the essential source of knowledge, member turnover can have significant implications on the survival and success of virtual communities. However, there is a dearth of research on the effect of membership turnover and even the method of measurement for membership turnover is left unclear in virtual communities. In a traditional context, membership turnover is calculated as the ratio of the number of departing members to the average number of members for a given time period. In virtual communities, while the influx of newcomers can be clearly measured, the magnitude of departure is elusive since explicit withdrawals are seldom executed. In addition, there doesn't exist a common way to determine the average number of community members who return and contribute intermittently at will. This study initially examines the limitations in applying the concept of traditional turnover to virtual communities, and proposes five membership fluidity measures based on a preliminary analysis of editing behaviors of 2,978 featured articles in English Wikipedia. Subsequently, this work investigates the relationships between three selected membership fluidity measures and group collaboration performance, reflecting a moderating effect dependent on work characteristic. We obtained the following results: First, membership turnover relates to collaboration efficiency in a right-shortened U-shaped manner, with a moderating effect from work characteristic; given the same turnover rate, the promotion likelihood for a more professional task is lower than that for a less professional task, and the likelihood difference diminishes as the turnover rate increases. Second, contribution period relates to collaboration efficiency in a left-shortened U-shaped manner, with a moderating effect from work characteristic; the marginal performance change per unit change of contribution period is greater for a less professional task. Third, the number of new participants per month relates to collaboration efficiency in a left-shortened reversed U-shaped manner, for which the moderating effect from work characteristic appears to be insignificant.

• Journal of Intelligence and Information Systems
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• v.18 no.4
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• pp.97-116
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• 2012

Conceptual modeling is an important step for successful system development. It helps system designers and business practitioners share the same view on domain knowledge. If the work is successful, a result of conceptual modeling can be beneficial in increasing productivity and reducing failures. However, the value of conceptual modeling is unlikely to be evaluated uniformly because we are lack of agreement on how to elicit concepts and how to represent those with conceptual modeling constructs. Especially, designing relationships between components, also known as part-whole relationships, have been regarded as complicated work. The recent study, "Representing Part-Whole Relations in Conceptual Modeling : An Empirical Evaluation" (Shanks et al., 2008), published in MIS Quarterly, can be regarded as one of positive efforts. Not only the study is one of few attempts of trying to clarify how to select modeling alternatives in part-whole design, but also it shows results based on an empirical experiment. Shanks et al. argue that there are two modeling alternatives to represent part-whole relationships : an implicit representation and an explicit one. By conducting an experiment, they insist that the explicit representation increases the value of a conceptual model. Moreover, Shanks et al. justify their findings by citing the BWW ontology. Recently, the study from Shanks et al. faces criticism. Allen and March (2012) argue that Shanks et al.'s experiment is lack of validity and reliability since the experimental setting suffers from error-prone and self-defensive design. They point out that the experiment is intentionally fabricated to support the idea, as such that using concrete UML concepts results in positive results in understanding models. Additionally, Allen and March add that the experiment failed to consider boundary conditions; thus reducing credibility. Shanks and Weber (2012) contradict flatly the argument suggested by Allen and March (2012). To defend, they posit the BWW ontology is righteously applied in supporting the research. Moreover, the experiment, they insist, can be fairly acceptable. Therefore, Shanks and Weber argue that Allen and March distort the true value of Shanks et al. by pointing out minor limitations. In this study, we try to investigate the dispute around Shanks et al. in order to answer to the following question : "What is the proper value of the study conducted by Shanks et al.?" More profoundly, we question whether or not using the BWW ontology can be the only viable option of exploring better conceptual modeling methods and procedures. To understand key issues around the dispute, first we reviewed previous studies relating to the BWW ontology. We critically reviewed both of Shanks and Weber and Allen and March. With those findings, we further discuss theories on part-whole (or part-of) relationships that are rarely treated in the dispute. As a result, we found three additional evidences that are not sufficiently covered by the dispute. The main focus of the dispute is on the errors of experimental methods: Shanks et al. did not use Bunge's Ontology properly; the refutation of a paradigm shift is lack of concrete, logical rationale; the conceptualization on part-whole relations should be reformed. Conclusively, Allen and March indicate properly issues that weaken the value of Shanks et al. In general, their criticism is reasonable; however, they do not provide sufficient answers how to anchor future studies on part-whole relationships. We argue that the use of the BWW ontology should be rigorously evaluated by its original philosophical rationales surrounding part-whole existence. Moreover, conceptual modeling on the part-whole phenomena should be investigated with more plentiful lens of alternative theories. The criticism on Shanks et al. should not be regarded as a contradiction on evaluating modeling methods of alternative part-whole representations. To the contrary, it should be viewed as a call for research on usable and useful approaches to increase value of conceptual modeling.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.243-264
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• 2018

Although the worldwide battery market is recently spurring the development of lithium secondary battery, lead acid batteries (rechargeable batteries) which have good-performance and can be reused are consumed in a wide range of industry fields. However, lead-acid batteries have a serious problem in that deterioration of a battery makes progress quickly in the presence of that degradation of only one cell among several cells which is packed in a battery begins. To overcome this problem, previous researches have attempted to identify the mechanism of deterioration of a battery in many ways. However, most of previous researches have used data obtained in a laboratory to analyze the mechanism of deterioration of a battery but not used data obtained in a real world. The usage of real data can increase the feasibility and the applicability of the findings of a research. Therefore, this study aims to develop a model which predicts the battery deterioration using data obtained in real world. To this end, we collected data which presents change of battery state by attaching sensors enabling to monitor the battery condition in real time to dozens of golf carts operated in the real golf field. As a result, total 16,883 samples were obtained. And then, we developed a model which predicts a precursor phenomenon representing deterioration of a battery by analyzing the data collected from the sensors using machine learning techniques. As initial independent variables, we used 1) inbound time of a cart, 2) outbound time of a cart, 3) duration(from outbound time to charge time), 4) charge amount, 5) used amount, 6) charge efficiency, 7) lowest temperature of battery cell 1 to 6, 8) lowest voltage of battery cell 1 to 6, 9) highest voltage of battery cell 1 to 6, 10) voltage of battery cell 1 to 6 at the beginning of operation, 11) voltage of battery cell 1 to 6 at the end of charge, 12) used amount of battery cell 1 to 6 during operation, 13) used amount of battery during operation(Max-Min), 14) duration of battery use, and 15) highest current during operation. Since the values of the independent variables, lowest temperature of battery cell 1 to 6, lowest voltage of battery cell 1 to 6, highest voltage of battery cell 1 to 6, voltage of battery cell 1 to 6 at the beginning of operation, voltage of battery cell 1 to 6 at the end of charge, and used amount of battery cell 1 to 6 during operation are similar to that of each battery cell, we conducted principal component analysis using verimax orthogonal rotation in order to mitigate the multiple collinearity problem. According to the results, we made new variables by averaging the values of independent variables clustered together, and used them as final independent variables instead of origin variables, thereby reducing the dimension. We used decision tree, logistic regression, Bayesian network as algorithms for building prediction models. And also, we built prediction models using the bagging of each of them, the boosting of each of them, and RandomForest. Experimental results show that the prediction model using the bagging of decision tree yields the best accuracy of 89.3923%. This study has some limitations in that the additional variables which affect the deterioration of battery such as weather (temperature, humidity) and driving habits, did not considered, therefore, we would like to consider the them in the future research. However, the battery deterioration prediction model proposed in the present study is expected to enable effective and efficient management of battery used in the real filed by dramatically and to reduce the cost caused by not detecting battery deterioration accordingly.

• Journal of Navigation and Port Research
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• v.42 no.4
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• pp.245-252
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• 2018

A method of transmitting an alert signal in case of man-overboard (MOB) systems in a small fishing vessel navigating within coastal area is being operated as VHF-DSC equipment via a distress alert button and V-P ass Equipment via alert button or beacon separation. However, a small fishing vessel with a couple of crews on board is an inappropriate way to alert a man-overboard condition. However, internationally, MOB equipment using VHF-DSC, AIS, and Bluetooth technologies is used to transmit alert signals directly to the mother ship and other radio stations. In order to analyze the performance and technology of the MOB equipment operating in foreign countries, it was confirmed that the alarm signal can be received within a maximum of one nautical mile when the MOB device is on the water surface. An MOB device that meets domestic conditions needs to send an alarm signal to a station within the VHF communication range. However, in order to reduce the false alert signal, it is most appropriate to operate the VHF-DSC radio equipment installed on the ship remotely. Analysis of various technologies connecting the MOB and the VHF-DSC revealed that the Bluetooth system has advantages such as device miniaturization. When an emergency signal is transmitted from the MOB device, it can be received by a dedicated receiver and recognized through an external input terminal of the VHF-DSC equipment generating its own alarm. If the emergency situation cannot be processed at the mother ship, a distress alert is sent to all radio stations via VHF-DSC for response under emergencies faced by small fishing vessels.

• Journal of Agricultural Extension & Community Development
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• v.7 no.1
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• pp.121-136
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• 2000

This study reports on a comparison between the Korean diffusion of agricultural innovation or extension service and the cooperative extension service in the United States of America. It focuses on relevant differences between the two systems and provides recommendation for improvement of the Korean system to insure success in important areas related to the diffusion of agricultural innovations. After a comparative study on diffusion of innovations it is clear that: in order to have a productive agriculture that makes effective and efficient use of natural resources and helps achieve sustainability goals, a mechanism that delivers knowledge to agricultural communities must be established and maintained. This mechanism is clearly an agricultural extension service that is cooperatively funded by federal, state and local governments and that insures participation of constituents in the process of establishing priorities and evaluating achievements. The success of US agriculture, the most productive in the world, is to a large degree to the Cooperative Extension Service. Based on the results of this study and the differences of the United States and Korea, the following recommendations should be emphasized for more effective communication for agricultural innovation and rural development in Korea: 1) In order to insure that extension educators are high caliber professional individuals, it is important to establish a system that nationally recognizes these individuals as such, and that provides a professional development path. 2) The results of the decision of transfer of extension educators to local governments has not yielded positive outcomes, especially in terms of professional status. It is clearly demonstrable that valuable professionals are leaving the service, that local governments do not have the will and resources to implement a successful extension program. 3) Because of the critical importance of diffusing innovations to agricultural producers in order to insure and quality and steady food supply, it is of critical importance that these issues be addressed before the extension service is further deteriorated. Given the cement situation, it is clear that the extension service should become nationally supported again in cooperation with local and state governments and that extension professionals be given appropriate rank at the national level, commesurate with their peers in research and teaching. 4) The common current committee practice of lengthy reporting and short discussion needs to be changed to one that results in char, brief and substantive action oriented goals. Joint participation by researchers, extension educators and farmers should be encouraged in planning, implementation and evaluation of communication for agricultural innovations. Roles and functions of committees for institutional cooperation, and or agricultural extension committees should be enlarged. 5) Extension educators should be encouraged to adopt new communication technologies to improve their diffusion of innovations methods. Agricultural institutions and organizations should be encouraged to adopt farmer-first and or client-oriented approach in agricultural extension and diffusion of agricultural technologies. The number, complexity and rapid change of information in agricultural extension require the development of a computer based information and report system to support agricultural extension. 6) To facilitate and expand the further development of communication for agricultural innovation and rural development, agricultural communication programs in universities especially in colleges of agriculture and life sciences. 7) To strengthening the sense of national and social responsibility communication for agricultural innovation and rural development among students in agricultural colleges and universities through participation in learning activities by proactive recruitment. 8) To establish and reinforce a policy that insures participation in communication for agricultural innovation and regal development activities. 9) To improve further development of communication for agricultural innovation and rural development in Korea, more research activities should be encouraged.

• Korean Security Journal
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• no.21
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• pp.75-94
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• 2009

Since mechanical security systems are mostly composed of electronic, information and communication devices, they have effects in the aspects of overall social environment and crime-oriented environment. Also, the importance is increasing for wireless recognition of RFID and tracing function, which will be usefully utilized in controlling the incomings and outgoings of people/vehicles or allowance, surveillance and control. This is resulting from the increase in the care for the elderly according to the overall social environment, namely, the aging society, and the number of women entering, as well as the increase in the number of heinous crimes. The purpose of this study is to examine the theoretical considerations on ubiquitous sensor network and present a direction for securities companies for their development by focusing on the technological and application areas. To present strategies of response to a new environment for security companies, First, a diversification strategy is needed for security companies. The survival of only high level of security companies in accordance with the principle of liberal market competition will bring forth qualitative growth and competitiveness of security market. Second, active promotion by security companies is needed. It is no exaggeration to say that we are living in the modern society in the sea of advertisements and propaganda. The promotional activities that emphasize the areas of activity or importance of security need to be actively carried out using the mass media to change the aware of people regarding security companies, and they need to come up with a plan to simultaneously carry out the promotional activities that emphasize the public aspect of security by well utilizing the recent trend that the activities of security agents are being used as a topic in movies or TV dramas. Third, technically complementary establishment of ubiquitous sensor network and electronic tag is needed. Since they are used in mobile electronic tag services such as U-Home and U-Health Care, they are used throughout our lives by forming electronic tag environment within safe ubiquitous sensor network based on the existing privacy guideline for the support of mobile electronic tag terminal commercialization, reduction in communication and information usage costs, continuous technical development and strengthening of privacy protection, and the system of cooperation of academic-industrial-research needs to be established among the academic world and private research institutes for these parts.

• Archives of design research
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• v.12 no.1
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• pp.145-154
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• 1999

With the introduction of digital technology since the late 1970s, we have been shifting from the industrial era into the information age. New communication systems have changed our concept of reality. Korea has a wealthy communication heritage with its own language and alphabet. However, Korean typography today has struggled to keep its originality, and does not hold up well to international standards. Korean contemporary typography is not efficient for communicating. It is not orderly, organised and simple. It has currently become complicated and decorative. Moreover, many young designers are attracted by imitations of western trends. It is now time for Korea to reveal its own identity. How can it develop a new typographic language that is more sympathetic to Korean tradition\ulcorner How will Korean information design produce a contemporary style with international relevance that contributes to world culture\ulcorner This thesis will be developed a new Korean typographic language that relies more on Korean traditions. Simultaneously, in this thesis will be examined Swiss typography as a relevant style for a new Korean typography to incorporate. Swiss typography maintained a similar philosophy to Korean tradition with its emphasis on clarity and simplicity. This study will be explored the potential of creating a contemporary Korean typographic solution which combines the traditions of Korea with the clarity of Swiss typography. The first attitude of the new typographic language should focus on legibility. The second condition of the new typographic philosophy based on the ability of designers is interpretation of context. The third concept of the new language is founded on an objective, rational design attitude. The final mental attitude of the new typographic language should feel a deep obligation to traditions. It is crucial time for Korean alphabet to establish a relevant standard rather than goes uncritically with the international current. Korea has had worthy traditions. It is suggested that the answers to 'good design' lie in the study of Korea's own history. Simultaneously, the research of Swiss design which is a

• Journal of Life Science
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• v.25 no.6
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• pp.624-630
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• 2015

This study examined the genetic distance among Chikso (Korea native brindle cattle) in nine regional areas using allele frequencies and a genetic diversity analysis with microsatellite markers. The analysis of the genetic diversity and genetic relationships of 2068 Chikso (383 KW, 180 GG, 52 KN, 129 KB, 332 UL, 24 JN, 198 JB, 148 CN, 622 CB) was carried out using 11 microsatellite markers. The number of alleles, observed heterozygostiy (H_obs), expected heterozygosity (H_exp), and polymorphism information content (PIC) of the 11 microsatellite markers were 8–24, 0.672–0.834, 0.687–0.886, and 0.638–0.876, respectively. The expected probability of identity values in random individuals (PI), random half-sib (PI_half-sibs), and random sibs (PI_sibs) were estimated to be 5.24×10⁻¹⁹, 2.63×10⁻⁰⁶, and 2.63× 10⁻⁰⁶, respectively, indicating that these markers can be used for traceability systems in Chikso cattle. The results of a phylogenetic tree (neighbor-joining tree), principle component analysis (PCA), and factorial component analysis (FCA) revealed genetic distance among nine Chikso populations. In conclusion, this study provides useful basic data that can be utilized in Chikso breeding and development. In addition, we will have to manage and conserve as a valuable genetic resource, without losing diversity of Chikso.

• 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.