• KDI Journal of Economic Policy
• /
• v.36 no.2
• /
• pp.175-196
• /
• 2014

This paper is a theoretical attempt to analyze and understand Yeonjulmang and Yeongyeolmang, which are terms for social networks with negative and positive connotation respectively in Korean Sociology. To do that, we analyze a social network where unilateral help are reciprocated. A social network in this context is a network where the past behaviors of its members are transmitted. With the information how the members behaved before, a social norm can emerge in the network, which facilitate the indirect reciprocation of unilateral help. In this norm, an agent's helping now will be rewarded by his being helped in the future. Since the reward happens in the future, this norm may not be sustained even if it is efficient. To sustain the reciprocation of the help, a norm can evolve to punish the violation of the norm more severely. If the punishment becomes too severe, the reciprocation of the help can be sustained even if it is not efficient any more in that the cost of help exceeds the benefit. If we allow the exit of the network, members have incentive to do it as belonging to the network is not beneficial any more. Then the social network may collapse. To avoid the collapse of the network, the exclusive norm, which exclude even mutually beneficial relationship with outsiders, may emerge. This can explain the emergence of Yeonjulmang, or a closed network, which is inefficient in double senses; 1) it may sustain inefficient reciprocation of help, and 2) the mutually beneficial relationship is excluded between an insider and an outsider of the network.

• Strategy21
• /
• s.44
• /
• pp.5-27
• /
• 2018

The purpose of this paper is to look at USN's efforts to rebuild its combat power in the face of a reemergence of great powers competition, and to propose some recommendations for the ROKN. In addition to the plan to augment its fleet towards a 355-ships capacity, the USN is pursuing to improve exponentially combat lethality(quality) of its existing fleet by means of innovative science and technology. In other words, the USN is putting its utmost efforts to improve readiness of current forces, to modernize maintenance facilities such as naval shipyards, and simultaneously to invest in innovative weapons system R&D for the future. After all, the USN seems to pursue innovations in advanced military Science & Technology as the best way to ensure continued supremacy in the coming strategic competition between great powers. However, it is to be seen whether the USN can smoothly continue these efforts to rebuild combat strength vis-a-vis its new competition peers, namely China and Russian navy, due to the stringent fiscal constraints, originating, among others, from the 2011 Budget Control Act effective yet. Then, it seems to be China's unilateral and assertive behaviors to expand its maritime jurisdiction in the South China Sea that drives the USN's rebuild-up efforts of the future. Now, some changes began to be perceived in the basic framework of the hitherto regional maritime security, in the name of declining sea control of the USN as well as withering maritime order based on international law and norms. However, the ROK-US alliance system is the most excellent security mechanism upon which the ROK, as a trading power, depends for its survival and prosperity. In addition, as denuclearization of North Korea seems to take significant time and efforts to accomplish in the years to come, nuclear umbrella and extended deterrence by the US is still noting but indispensible for the security of the ROK. In this connection, the naval cooperation between ROKN and USN should be seen and strengthened as the most important deterrents to North Korean nuclear and missile threats, as well as to potential maritime provocation by neighboring countries. Based on these observations, this paper argues that the ROK Navy should try to expand its own deterrent capability by pursuing selective technological innovation in order to prevent this country's destiny from being dictated by other powers. In doing so, however, it may be too risky for the ROK to pursue the emerging, disruptive innovative technologies such as rail gun, hypersonic weapon... etc., due to enormous budget, time, and very thin chance of success. This paper recommends, therefore, to carefully select and extensively invest on the most cost-effective technological innovations, suitable in the operational environments of the ROK. In particular, this paper stresses the following six areas as most potential naval innovations for the ROK Navy: long range precision strike; air and missile defense at sea; ASW with various unmanned maritime system (UMS) such as USV, UUV based on advanced hydraulic acoustic sensor (Sonar) technology; network; digitalization for the use of AI and big data; and nuclear-powered attack submarines as a strategic deterrent.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.10
• /
• pp.6114-6125
• /
• 2014

This paper analyzed the issues related to focus on farmers behaviors of energy saving facilities. This study conducted questionnaire and field surveys of controlled horticulture farmers and economic analysis using an IPA(Importance-Performance Analysis) matrix. According to the research results, the performance level was low on average ranging from 2.33 to 2.56 in a five point Likert-scale on greenhouse mandarin and grape-related facilities. On the other hand, the importance levels were high in the mean rating from 2.69 to 4.8. The results show that energy loss reduction of complementary facility and alternative energy supply support for low cost implementation are more important in terms of the respondents concerns than performance quadrant III. Therefore, it is important to provide financial support to energy-saving facilities to promote the use of energy efficiency improvement. In addition, the government should invest continuously in research and development.

• Journal of the Korean Society of School Health
• /
• v.8 no.1
• /
• pp.143-154
• /
• 1995

Korea has been recently reducing the quality of life as well as rising medical cost because of the increase of chronic diseases. But we can prevent those chronic diseases through the improvement of environment or life style. We evaluated the educational effectiveness of chronic diseases(hypertention, diabetes, cancer, stroke and other chronic diseases) designed to increase the knowledge, attitude and practice of chronic diseases among university students. Between August 1994 and November 1994, we implemented chronic diseases prevention instruction in intervention students; unmatched control students were selected in same university. We conducted pre- and post-intervention surveys both intervention and control students with self-reported questionnaires(50 items). We assigned score(0-4 points) to items and conducted a analysis of covariance(ANCOVA) with sex, grade and economic status as the covariate, using the SAS PC computer statistical package. And we culculated odds ratio with safety scores between intervention and control students. The results of this study were followed. 1. In demographic characteristics of subjects both pre- and post intervention, we found no significant differences in intervention and control students at religion, father's education, mother's education, mother's occupation and type of residence(p>0.05), but we found significant differences at sex(p<0.001), grade(p<0.001) and economic status(p<0.05). 2. The sex, grade and economic status-adjusted mean prevention knowledge scores for diabetes and stroke increased from the pre- to post-survey in the intervention students(p<0.001), but control students did not increased(p>0.05). As odds ratios in knowledge were below 1, the knowledge of intervention students were higher than control students. 3. The attitudes for general adult health increased from the pre- to post-survey in the intervention students(p<0.05), but control students did not increased(p>0.05). As odds ratios in attitudes were approximately 1, we can not say effectiveness in intervention students 4. The pratices for cancer and stroke increased from the pre- to post-survey in both the intervention and control students(p<0.001). Also odds ratio of hypertention was 0.91, and that of stroke was 1.14. 5. Health related behaviors did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). But odds ratio of drinking was 0.76 and that of body weight was 1.21. 6. Health status did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). As odds ratio of health status was 1.09, prevention education was not effect in intervention students We would like to recommend as follows; 1. University students must learn about prevention of chronic diseases. Because the knowledge of invetervention students was higher than that of control students. 2. The prevention education of chronic diseases should be taught from primary school. 3. Adult health education for university students must be practiced continuously. Education period(l5 weeks) in this study was not complete. 4. The evaluation of chronic diseases was conducted real measurement(such as BP check) as well as self reported-survey. 5. Educational materials(video tape, pamphlet) related the prevention of chronic diseases should be developed at national level. And we must easely use those materials. 6. The prevention education of chronic diseases should be made through mass media as well as school education.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.77-77
• /
• 2000

Titanium oxide (TiO2) thin films have valuable properties such as a high refractive index, excellent transmittance in the visible and near-IR frequency, and high chemical stability. Therefore it is extensively used in anti-reflection coating, sensor, and photocatalysis as electrical and optical applications. Specially, TiO2 have a high dielectric constant of 180 along the c axis and 90 along the a axis, so it is highlighted in fabricating dielectric capacitors in micro electronic devices. A variety of methods have been used to produce patterned self-assembled monolayers (SAMs), including microcontact printing ($\mu$CP), UV-photolithotgraphy, e-beam lithography, scanned-probe based micro-machining, and atom-lithography. Above all, thin film fabrication on $\mu$CP modified surface is a potentially low-cost, high-throughput method, because it does not require expensive photolithographic equipment, and it produce micrometer scale patterns in thin film materials. The patterned SAMs were used as thin resists, to transfer patterns onto thin films either by chemical etching or by selective deposition. In this study, we deposited TiO2 thin films on Si (1000 substrateds using titanium (IV) isopropoxide ([Ti(O(C3H7)4)] ; TIP as a single molecular precursor at deposition temperature in the range of 300-$700^{\circ}C$ without any carrier and bubbler gas. Crack-free, highly oriented TiO2 polycrystalline thin films with anatase phase and stoichimetric ratio of Ti and O were successfully deposited on Si(100) at temperature as low as 50$0^{\circ}C$. XRD and TED data showed that below 50$0^{\circ}C$, the TiO2 thin films were dominantly grown on Si(100) surfaces in the [211] direction, whereas with increasing the deposition temperature to $700^{\circ}C$, the main films growth direction was changed to be [200]. Two distinct growth behaviors were observed from the Arhenius plots. In addition to deposition of THe TiO2 thin films on Si(100) substrates, patterning of TiO2 thin films was also performed at grown temperature in the range of 300-50$0^{\circ}C$ by MOCVD onto the Si(100) substrates of which surface was modified by organic thin film template. The organic thin film of SAm is obtained by the $\mu$CP method. Alpha-step profile and optical microscope images showed that the boundaries between SAMs areas and selectively deposited TiO2 thin film areas are very definite and sharp. Capacitance - Voltage measurements made on TiO2 films gave a dielectric constant of 29, suggesting a possibility of electronic material applications.

• Journal of Digital Forensics
• /
• v.12 no.3
• /
• pp.1-8
• /
• 2018

A random chat application is a type of social dating application that helps people find a lover or spouse by randomly connecting and providing services such as text, voice and video chat. Recently, there has been globally a rapid increase in its use due to the fact that it provides people to quick and convenient encounters at low cost. However, it is used as one of method to prostitute or to trade drugs and become a cause of violent crimes due to various criminal occurring after actual meeting between app users. For this reason, a random chat application is likely to provide proof of prostitution or drug trade and clues to arrest rape, kidnapping and murder suspects. Thus, it is necessary to analyse random chat applications from the viewpoint of digital forensics investigation, but there is no related research at all. Therefore, in this paper, we analyzed artifacts of 6 Korea random chat application's user behaviors; Ranchat, AngTalk, SsumgThing, DaTalk, EveryTalk and Sail. As a result, we found that it is remain on mobile device that time and contents of message transmission/reception, sender/receiver, friend profile and user account creation time when user is using the applications.

• Asia Marketing Journal
• /
• v.15 no.2
• /
• pp.75-97
• /
• 2013

While good return policies are suggested as one of the critical services for e-commerce, ambivalence between the burden of the cost and shoppers' satisfaction may prevent e-tailers from increasing their level of leniency. Based on the S-O-R model, this study has attempted to develop a grounded theory to explain how lenient return policies shape online shoppers' perceptions and responses, with a focus on cultural influences in the relationship. In order to check the cultural effects of the lenient return policy, thirty two female and eleven male undergraduate students in South Korean shoppers, who are accustomed to strict return policies, participated in the semi-structured interview. A series of open-ended questions were designed to explore consumers' reactions toward four different levels of the lenient return policy: from the strict type in South Korea to the lenient type in the U.S. Using qualitative research methods, this research has defined three types of dimensions of lenient return policy: return possible period, complexity of progress, and other restrictions. While previous researchers did not pay much attention, the last dimension, other restrictions, is shown to be the most significant in influencing online shoppers' perceptions, especially in South Korea. Also, the impacts on online shoppers' perceptions from the three types of sub-dimensions of return policy were somewhat different. Whereas a longer return possible period was considered more favorable, a medium level of complexity and restrictions were considered more desirable. In summary, this result showed that shoppers in Eastern cultures, i.e. South Korean online shoppers, seem favorable to a medium level of lenient return policies, while allowing for taking precautions against possible fraudulent behaviors and setting other restrictions. Therefore, most of retailers in South Korea recommended that e-tailers who adopt the most lenient return policies raise the bar to guard ethical shoppers from fraudulent users. Next, lenient return policies can enhance ease of use, usefulness, affect, and trust while relieving perceived risk, which is connected to intention to purchase, satisfaction, and loyalty. Interestingly, lenient return policies are more likely to change the behavioral responses of online shoppers, such as return and purchase, rather than change their attitudes or beliefs such as image, satisfaction, and loyalty. This tendency can be seen more clearly in the direct influences of return policy on responses. The reaction to lenient return policy is mostly the intention to return or to purchase. This suggests that return policy serves the e-tailers as a powerful tool in increasing online shoppers' purchase intention at the moment of purchase. Therefore, e-tailers who plan to expand their market to eastern countries, including South Korea, have to build a shield of restrictions around their lenient return policy, rather than immediately applying their original liberalized return policy. Also, e-tailers in South Korea need to review their strict and undifferentiated return policies to deal with the unsatisfied reactions of online shoppers toward their normal return policies. Although the present study was confined to the return policies currently being practiced by popular e-tailers, it would be worthwhile to develop effective return policies separately for each country, especially South Korea, keeping the culture of the relevant country in mind.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.480-493
• /
• 2007

Many railway-advanced countries are using the various types of track to reduce the track maintenance and repair cost according to the improvement of velocity. It spends on much maintenance and repair cost for ballast track due to abrasion of ballast, track irregularity and unisotropical ballast-support stiffness. The ballast track on railway bridge is accelerating the deterioration of ballast according to interaction of railway bridge and track. As continuing the deterioration, it is caused dynamic loads. Due to these effects, it increases negative loads of track and bridge. However, when designing the railway bridge, the effect of ballast track was applicate only dead load, so elastic behavior effect of ballast track is not influenced. Therefore, this paper presumes the stiffness of ballast track on railway bridge considering dynamic behavior of railway bridge, it was evaluated that effect on dynamic behaviors of railway bridge according to ballast track stiffness.

• Asia pacific journal of information systems
• /
• v.24 no.4
• /
• pp.493-513
• /
• 2014

With the development of related technologies, Location-Based Services (LBS) are growing fast and being used in many ways. Past LBS studies have focused on adoption of LBS because of the fact that LBS users have privacy concerns regarding revealing their location information. Meanwhile, the number of LBS users and revenues from LBS are growing rapidly because users can get some benefits by revealing their location information. Little research has been done on how LBS affects consumers' information search behavior in product purchase. The purpose of this paper is examining the effect of LBS information filtering on buyers' uncertainty and their information search behavior. When consumers purchase a product, they try to reduce uncertainty by searching information. Generally, there are two types of uncertainties - knowledge uncertainty and choice uncertainty. Knowledge uncertainty refers to the lack of information on what kinds of alternatives are available in the market and/or their important attributes. Therefore, consumers having knowledge uncertainty will have difficulties in identifying what alternatives exist in the market to fulfil their needs. Choice uncertainty refers to the lack of information about consumers' own preferences and which alternative will fit in their needs. Therefore, consumers with choice uncertainty have difficulties selecting best product among available alternatives.. According to economics of information theory, consumers narrow the scope of information search when knowledge uncertainty is high. It is because consumers' information search cost is high when their knowledge uncertainty is high. If people do not know available alternatives and their attributes, it takes time and cognitive efforts for them to acquire information about available alternatives. Therefore, they will reduce search breadth. For people with high knowledge uncertainty, the information about products and their attributes is new and of high value for them. Therefore, they will conduct searches more in-depth because they have incentive to acquire more information. When people have high choice uncertainty, people tend to search information about more alternatives. It is because increased search breadth will improve their chances to find better alternative for them. On the other hand, since human's cognitive capacity is limited, the increased search breadth (more alternatives) will reduce the depth of information search for each alternative. Consumers with high choice uncertainty will spend less time and effort for each alternative because considering more alternatives will increase their utility. LBS provides users with the capability to screen alternatives based on the distance from them, which reduces information search costs. Therefore, it is expected that LBS will help users consider more alternatives even when they have high knowledge uncertainty. LBS provides distance information, which helps users choose alternatives appropriate for them. Therefore, users will perceive lower choice uncertainty when they use LBS. In order to test the hypotheses, we selected 80 students and assigned them to one of the two experiment groups. One group was asked to use LBS to search surrounding restaurants and the other group was asked to not use LBS to search nearby restaurants. The experimental tasks and measures items were validated in a pilot experiment. The final measurement items are shown in Appendix A. Each subject was asked to read one of the two scenarios - with or without LBS - and use a smartphone application to pick a restaurant. All behaviors on smartphone were recorded using a recording application. Search breadth was measured by the number of restaurants clicked by each subject. Search depths was measured by two metrics - the average number of sub-level pages each subject visited and the average time spent on each restaurant. The hypotheses were tested using SPSS and PLS. The results show that knowledge uncertainty reduces search breadth (H1a). However, there was no significant correlation between knowledge uncertainty and search depth (H1b). Choice uncertainty significantly reduces search depth (H2b), but no significant relationship was found between choice uncertainty and search breadth (H2a). LBS information filtering significantly reduces the buyers' choice uncertainty (H4) and reduces the negative relationship between knowledge uncertainty and search breadth (H3). This research provides some important implications for service providers. Service providers should use different strategies based on their service properties. For those service providers who are not well-known to consumers (high knowledge uncertainty) should encourage their customers to use LBS. This is because LBS would increase buyers' consideration sets when the knowledge uncertainty is high. Therefore, less known services have chances to be included in consumers' consideration sets with LBS. On the other hand, LBS information filtering decrease choice uncertainty and the near service providers are more likely to be selected than without LBS. Hence, service providers should analyze geographically approximate competitors' strength and try to reduce the gap so that they can have chances to be included in the consideration set.

• Journal of Korean Home Economics Education Association
• /
• v.30 no.4
• /
• pp.141-164
• /
• 2018

The purpose of this study was to investigate the stress perception, dietary habits, lifestyle and snack intake behaviors of students to help dietary education of high school students in Jeonnam area. The data were collected from high school students in Jeonnam area and 503 questionnaires were used for analysis. The main results of this study are as follows. First, the mean scores of high school students' perception of stress were 2.92 points for male students and 3.07 points for female students, and female students were statistically significantly higher than male students(p<.01). Stress perceptions showed significant differences in school stress(p<.001) and family stress(p<.05) according to gender, and female students gained more stressed than male students. Second, the dietary habits and lifestyle characteristics of high school students by gender showed significant difference between male students and female students at the one meal time(p<.001), the amount of meal(p<.05), the tendency of eating habits(p<.001), the salty taste of food(p<.05), the exercise frequency per week(p<.001) and the exercise time per day(p<.001), respectively. One meal time was shorter for male students than for female students, and the amount of meals was more suitable amount for female students than male students. Also, male students ate more regularly than female students and female students preferred more stimulating foods than male students. Male students ate slightly bland salty taste, and female students ate standard salty taste. The exercise frequency per week and the exercise time per day were more in male students than in female students. Third, the snack intake characteristics of high school students by gender showed significantly different between male students and female students at the cost of snack per day(p<.01), the time to eat snacks(p<.01) and the favorite snacks(p<.001), respectively. The cost of snack per day was higher for female students than for male students in case of less than 4,000 won. The time for eating snack showed that 'Irregularly' was high for male students and 'In the evening after lunch' was high for female students. The favorite snacks were cookies, candies and chocolates for male and female students. Forth, the dietary habits and lifestyle characteristics of high school students by stress level showed significantly different at the frequency of daily meals(p<.05), the tendency of eating habits(p<.01) and the salty taste of food(p<.05), respectively. The frequency of daily meals was more than four times in case of the 'High stress' and 'Low stress' groups. The tendency of eating habit was low in regular meal rate in 'High stress' group. Fifth, the snack intake characteristics of high school students by stress level showed significantly different in the frequency of snacks per day(p<.05) and the favorite taste of snacks(p<.05). In case of the frequency of daily snack intake, 'More than 4 times' was highest in 'High stress' group and 'Low stress' group. The favorite taste of snacks showed that the spicy taste was highest in the 'High stress' group and the 'Low stress' group.