• 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.17 no.4
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• pp.95-108
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• 2011

TThis is a study of the personalization method that intelligently adapts the level of clustering considering purchasing index of a customer. In the e-biz era, many companies gather customers' demographic and transactional information such as age, gender, purchasing date and product category. They use this information to predict customer's preferences or purchasing patterns so that they can provide more customized services to their customers. The previous Customer-Segmentation method provides customized services for each customer group. This method clusters a whole customer set into different groups based on their similarity and builds predictive models for the resulting groups. Thus, it can manage the number of predictive models and also provide more data for the customers who do not have enough data to build a good predictive model by using the data of other similar customers. However, this method often fails to provide highly personalized services to each customer, which is especially important to VIP customers. Furthermore, it clusters the customers who already have a considerable amount of data as well as the customers who only have small amount of data, which causes to increase computational cost unnecessarily without significant performance improvement. The other conventional method called 1-to-1 method provides more customized services than the Customer-Segmentation method for each individual customer since the predictive model are built using only the data for the individual customer. This method not only provides highly personalized services but also builds a relatively simple and less costly model that satisfies with each customer. However, the 1-to-1 method has a limitation that it does not produce a good predictive model when a customer has only a few numbers of data. In other words, if a customer has insufficient number of transactional data then the performance rate of this method deteriorate. In order to overcome the limitations of these two conventional methods, we suggested the new method called Intelligent Customer Segmentation method that provides adaptive personalized services according to the customer's purchasing index. The suggested method clusters customers according to their purchasing index, so that the prediction for the less purchasing customers are based on the data in more intensively clustered groups, and for the VIP customers, who already have a considerable amount of data, clustered to a much lesser extent or not clustered at all. The main idea of this method is that applying clustering technique when the number of transactional data of the target customer is less than the predefined criterion data size. In order to find this criterion number, we suggest the algorithm called sliding window correlation analysis in this study. The algorithm purposes to find the transactional data size that the performance of the 1-to-1 method is radically decreased due to the data sparity. After finding this criterion data size, we apply the conventional 1-to-1 method for the customers who have more data than the criterion and apply clustering technique who have less than this amount until they can use at least the predefined criterion amount of data for model building processes. We apply the two conventional methods and the newly suggested method to Neilsen's beverage purchasing data to predict the purchasing amounts of the customers and the purchasing categories. We use two data mining techniques (Support Vector Machine and Linear Regression) and two types of performance measures (MAE and RMSE) in order to predict two dependent variables as aforementioned. The results show that the suggested Intelligent Customer Segmentation method can outperform the conventional 1-to-1 method in many cases and produces the same level of performances compare with the Customer-Segmentation method spending much less computational cost.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.86-97
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• 2015

"The Jayeon Madang Development Project("JMDP")" is a project being promoted by the Ministry of Environment to create a cultural space and a natural rest area within the city. Abuksan, located at Abuksan in Gyeongsangnam-do Miryang-si Naeil-dong, has suffered a substantial amount of environmental degradation over time, so the need for ecological restoration made it a natural choice for the location of the JMDP's site. The purpose of this study is to examine ecological restoration design strategies used in Abuksan as part of the JMDP using system dynamics. The national archery center, hole, and arable land sites are key restoration areas in Abuksan that have faced with ecological problems. In this study, we identified the status of each site, determined key strategies being implemented, and designed based on the strategies implemented up to this point for solving problems associated with each sites through the use of causal loop diagrams. The results of the causal loop diagram analysis are as follows. The national archery center site was designed around strategies including planting green manure crops and introducing hugelkultur to reduce soil acidification and green network degradation. The hole site was designed as a constructed wetland based on the emergence of hygropreference vegetation, hydrated by rainwater collected at the bottom of hole, ecological and cultural benefits of such an environment. The arable land site restoration design was built around planting native vegetation on one part of the arable land site after soil quality improved and around restoration of grassland and a dry wetland on the other part of the site to reduce soil acidification, erosion, and green network degradation. This study is a significant attempt to apply principles of system dynamics to ecological restoration by providing the design strategies using comprehension of some problems in the ecosystem feedback loops, which has not been used before in general design processes for ecological restoration.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.73-87
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• 2012

Nowadays, the Korean society is full of multiculturalism as there are many foreign ethnic enclaves. Many Chinese quarters are built in various parts of Korea along with the increasing population of Chinese immigrant. Especially, the Chinese quarter has shown the sign of time and the cultural characteristic of the local residents. This research is to study the market space of Chinese ethnic enclaves in Dairimdong. This research method is the field study to use a participant observation. Below are the research results: Chinese merchants put a private object such as "tanzi" on a sidewalk and install large awning covered full of sidewalk. Sidewalk transform from an outdoor space into an internal space because of Chinese merchants. Passers-by move to use vehicle roads and transform not only the car's space but also the passers-by space. Urban planners originally classify space into three categories, which are building - sidewalk - vehicles road. However, after Chinese came to the market, Chinese classified space into new three categories which is building - space for both sidewalk and "tanzi" - space for both sidewalk and vehicles road. New classification of space is quite different from the previous. In addition, Chinese thinks that the Dairimdong's Market is a very comfortable place. Because Dairimdong Market have many Chinese physical facilities. Next, Chinese thinks that the Dairimdong Market is a very friendly place to buy Chinese products easily. This market has become a place of consumption for the Chinese. Eventually, Dairimdong's Market has changed because of Chinese immigrants. It is possible to make satisfactory planning and design proposal to build Chinese quarters in the future through the explanation of space and status by way of culture. There are many careless mistakes in previous subjective planning and design proposal of the designers. Thus, it should consider the problems created by their way of use in later planning and design.

• Journal of Global Scholars of Marketing Science
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• v.20 no.1
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• pp.70-79
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• 2010

There has been some research conducted that addressed immoral consumer behaviors in Korea; however, most of this research focused on purchasing counterfeits or shoplifting. High return rates of apparel and used apparel returns have been acknowledged as problem areas within the fashion industry. However, very few researchers have addressed this issue. Therefore, the goal of this research was to explore consumer's retail borrowing experience using a mixed methods approach. In study 1 Korean consumer's retail borrowing experiences was explored through focus group interviews. Findings informed study 2 an examination of apparel consumers' attitudes toward retail borrowing behavior via an online survey. Findings assist both researchers' and practitioners' understanding of retail borrowing behaviors and provide insight into retail borrowing issues in the apparel retail industry. For study 1, five focus-group interviews were conducted with seven panels of individuals that had retail borrowing experience within the past year. Thirty-five Korean consumers who lived in a metropolitan area participated in the focus group interviews. Most of consumers were in their 20's (n=21) and were women (n=24). Most participants purchased apparel items from a retail store and returned the worn items for either a full refund or exchanged the worn item for another item. Motives underlying retail borrowing behavior included social needs, job-related needs, fashion needs, and "smart shopping." Similar to existing research findings from other countries, social needs were the most frequently mentioned cause of retail borrowing in fashion stores. Consumers' moral values, attitude toward large corporations, and prior retail borrowing experience were mentioned as possible factors affecting consumers' retail borrowing behavior. For study 2, the questionnaire used to gather the data was developed based on the findings of part I and existing research. Questions concerning consumers' moral beliefs, sensation seeking tendencies, self-worth, past retail job experience, retail borrowing experience, and some demographic characteristics were included in the questionnaire. The data were collected via an online survey using an online panel provided by a commercial online research company located in Seoul, Korea. In order to obtain various consumers, a quota sample was (male: female=1:1, 20's:30's:40's=1:1:1, retail experience: no retail experience=1:3) obtained from the company. A total of 401 consumers who had shopped for apparel items during the prior 6 months participated in the online survey. The results indicated that 19.7% of the respondents reported they had experience borrowing fashion merchandise. Among these individuals, male borrowers (57%) outnumbered female borrowers. In terms of age distribution, x2 revealed that there was a statistical difference between respondents with and without retail borrowing experiences: 41.8% of the respondents with retail borrowing experience were in their 40's, while respondents without retail borrowing experience were evenly distributed between their 20's to 40's. There was also a significant difference between respondents with and without retail borrowing experience in terms of income: respondents with retail borrowing experience tended to have higher incomes than those without retail borrowing experience. T-tests were performed to compare respondents' fashion shopping behavior, moral beliefs, sensation-seeking tendencies, and attitudes toward retail borrowing behavior between participants with and without retail borrowing experience. As compared to those with no borrowing experience, respondents with experience tended to shop for fashion items more frequently and spent more on shopping for fashion items. Consumers with experience borrowing tended to have higher sensation-seeking tendencies than consumers without retail borrowing experience. A regression analysis revealed that attitudes toward fashion retail borrowing were negatively related to consumers' moral beliefs, but positively related to monthly fashion shopping frequency, sensation-seeking tendencies, and past fashion retail borrowing experience. Among these variables, past retail borrowing experience was the most significant predictor, followed by moral beliefs. This research serves as an initial attempt to address the motives that underlie retail borrowing behaviors and the factors affecting those behaviors. The findings of this study may facilitate an understanding of the consumer's retail borrowing, which will provide a basis for approaches that may help decrease retail borrowing and inappropriate returns at fashion retail stores. The findings may also provide materials for consumer education over the long term. In order to better understand fashion retail borrowing behavior, more research is needed in the future.

• Management & Information Systems Review
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• v.36 no.4
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• pp.117-127
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• 2017

In recent times the size of the world IPO in general has skyrocketed. Specifically, China's financial market development is becoming important as both the size of China's capital market and the number of companies going public are gradually increasing. This has led to a rapid development of venture vapital(VC) institutions in China for the past couple of decades. This study focuses on one of the three markets of China's Shenzhen Stock Exchange-the Growth Enterprise Board((GEB) hereafter, ChiNext). The ChiNext is established in October, 2009 to enable hi-tech or high growth potential technology companies that find it relatively difficult to fulfil the listing requirements of either the Shenzhen Main Board or Small and Medium Size Enterprise Board(SMEB) to go public. This study covers a three-year period(2012/01/-2015/01) and analyze first day initial return of 83 venture capital-backed companies and 53 non-venture capital-backed companies using T-test. Regression analysis is used as to examine the variables affecting IPO's first-day return. The empirical results are four-fold. First, the level of first day return of venture-backed is significantly lower than non venture capital backed support in the Chinese venture capital market. Second, the level of first-day return of listed companies supported by foreign venture capital is significantly higher than that of companies receiving domestic venture capital support. Third, the firms that have a large number of venture capital firms showed a low level of first-day return. Fourth, regression result for the IPO first-day return which is as dependent variable indicates that the venture capital support(VCAP), number of venture capital(VCNum), offering size(Lnsize) and PER all affect have negative effect on the first day initial return. Also, the venture capital type(VCType), turnover ratio and the the firm type(Tech-firms) statistically affect IPO first day return positively. Finally, by shedding more light on the IPO first-day return, this paper provides meaningful information to investors about the Chinese IPO market.

• Journal of forensic and investigative science
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• v.1 no.1
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• pp.11-30
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• 2006

The preliminary investigative activities by the police officer play a critical role in identifying the cause of death in unnatural death investigations. The failure to secure the crime scene leads to the destruction of significant evidence, which results in the difficulty or impossibility to identify the cause of death. In order to prevent this jeopardizing crucial evidence, and to identify the level of preliminary investigation on the scene, this research is conducted and analyzed with questionnaires of 300 police first responders and 100 detectives. As a result, it was disclosed that there is a possibility for first responders to fail to ensure scene security, scene observation, and canvass interviews. Besides, when medical personnel have no choice but to contaminate the crime scene in order to save lives, it is necessary for them to take photos and to take proper actions before they enter the scene. The importance of scene-control education cannot be emphasized enough in order to prevent media from entering and destroying the evidence. Through research of actual conditions of unnatural death cases which occurred in Kyongbook Province for last five years, the statistics regarding a few different types of death were analyzed as follows. Evidence that homicide, suicide, accidental death, and disaster deaths have increased year by year. Therefore, it is deemed necessary for the government to take multilateral policies to reduce them, and for police to reinforce their investigative skills. Further, the insufficient number of autopsy facilities and forensic pathologists, only 13% of the deceased (1,237 cases) have had an autopsy conducted to identify the cause of death for last five years. The other, 87.3% (8,496 cases) of the deceased, were handled through simple postmortem examination. The significance of this percentage is that there is still the possibility not revealing the cause of unjust deaths. Therefore, it is necessary to furnish police agency with the reasonable amount of funding for autopsies and maintaining enough forensic pathologists.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.234-243
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• 2013

The aim of this study was to evaluate the quality characteristics and antioxidative properties of cookies supplemented with mulberry pomace (0%, 4%, 8%, 12%). The bulk density, spread ratio, and leavening rate of cookies decreased with increasing amounts of mulberry pomace. The lightness and b value (of the Hunter color system) decreased based on the amount of mulberry pomace. The pH of cookies decreased (acidity increased) with increasing mulberry pomace. The soluble solid content increased according to the amount of added mulberry pomace, but the amount of reducing sugars decreased. In texture analysis, cookies with 12% mulberry pomace had the highest hardness. Total phenol and flavonoid content increased according to the amount of mulberry pomace added. Antioxidant activities, such as DPPH radical scavenging, hydroxyl radical scavenging, ABTS radical scavenging, and FRAP were highest in cookies with 12% mulberry pomace. In the sensory evaluation, sensory scores for color, taste, flavor, texture, and overall preference were highest in cookies with 8% mulberry pomace. Thus, our results suggest that the optimum amount of mulberry pomace to add to cookies is 8%.

• Journal of Gastric Cancer
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• v.4 no.4
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• pp.272-276
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• 2004

Purpose: The incidence of nodal metastases is as low as 2 to $20\%$ in early gastric cancer, so there is a trend to lessen the extent of surgery. In addition, the adequate range for a lymphadenectomy is controversial, especially in early gastric cancer. In this study, we tried to find the minimal range for a lymphadenectomy by analyzing sentinel-node and solitary lymph-node metastases in gastric cancer. Materials and Methods: The total of 78 patients who underwent a curative gastrectomy with a D2 lymphadenectomy for early gastric cancer between 2000 and 2002 in the Department of Surgery, Yonsei University, Seoul, Korea, were included for the evaluation of sentinel-node metastases.. After a laparotomy, 25 mg of indocyanine green was mixed in 5 ml of normal saline, and all the dye was injected into the subserosal layer around the primary tumor. All nodes stained within 5 minutes were marked. In addition, a total of 141 patients, who underwent a curative gastrectomy between 1997 and 2001 at the Department of Surgery, Yonsei University, Seoul, Korea, were analyzed for solitary lymph- node metastases. Results: Among the 78 patients, sentinel nodes were detected in 69 patients ($88.5\%$). The sentinel nodes in 60 cases ($87.0\%$) were located in the perigastric area. However, 9 cases ($13.0\%$) had sentinel nodes in the N2 group. In the 141 cases that had a solitary metastatic node, 125 cases ($88.6\%$) demonstrated the metastatic lymph node in the perigastric area, and 16 cases ($11.4\%$) showed that the metastatic node in the N2 group. Conclusion: Taken together, removal of a perigastric lymph node could miss early metastases in gastric cancer, so a D1 lymphadenectomy should not be the minimal range of dissection if a lymphadenectomy is necessary. (J Korean Gastric Cancer Assoc 2004;4:272-276)

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1515-1520
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• 2012

This study evaluate the quality characteristics and antioxidative properties of acorn starch mook containing spirulina (0%, 0.5%, 1%, 1.5%) and soy protein (3%). The pH of acorn starch mook containing the spirulina and soy protein decreased with increasing amount of spirulina decrease in pH means an increase in acidity. In addition, the moisture content was 87%. The lightness of acorn starch mook containing spirulina and soy protein decreased with increasing amount of spirulina and soy protein. The L and a values of the Hunter color system were decreased significantly increasing spirulina content, and the b value increased. In contrast, with increasing spirulina and soy protein content, the L and a increased significantly and the b value. Texture analysis revealed higher hardness and springiness of acorn starch mook containing spirulina than the control. The total phenol content was highest in the acorn starch mook containing 1.5% spirulina and 3% soy protein. The antioxidant activities of the acorn starch mook containing spirulina and soy protein increased with increasing amount of spirulina and soy protein. The $IC_{50}$ value of 1.5% spirulina and 3% soy protein was 166.2 mg/mL for DPPH. The results of the sensory test were best in the acorn starch mook containing 1% spirulina.