• Journal of Intelligence and Information Systems
• /
• v.15 no.1
• /
• pp.31-50
• /
• 2009

As the collected information which is static or dynamic is infinite in ubiquitous computing environments, information overload and invasion of privacy have been pressing issues in the recommendation service. In this study, we propose a recommendation service procedure through P2P, The P2P helps customer to obtain effective and secure product information because of communication among customers who have the similar preference about the products without connection to server. To evaluate the performance of the proposed recommendation service, we utilized real transaction and product data of the Korean mobile company which service character images. We developed a prototype recommender system and demonstrated that the proposed recommendation service makes an effect on recommending product in the ubiquitous environments. We expect that the information overload and invasion of privacy will be solved by the proposed recommendation procedure in ubiquitous environment.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.2
• /
• pp.47-55
• /
• 2018

Purpose - To meet the needs of various customers in an uncertain market environment, many companies use product modularization strategies. Modularization of a product means that one product consists of several components and that the type of product can be changed according to the combination of components. The greatest feature of modularity is that changes in one component do not significantly affect the physical changes in the other component to which they are connected. Modularization of products is recognized as a very important strategy to reflect increasingly complicated customer requirements to products and respond to the needs of various markets. Many studies have been made in connection with the concept of mass customer satisfaction. There are many prior studies that modularization of such products positively affects the operational performance (manufacturing cost, fast delivery, etc.) and innovation of the product. However, excessive modularization has been found to have a negative effect on this performance. However, there are very few studies on the nonlinear relationship between product modularization and customer satisfaction. Supplementing these academically insufficient parts is very necessary when considering the current market environment. Research design, data, and methodology - In order to make up for the shortcomings of academic research in Korea, this study collects data through questionnaires in electronic, auto, and defense industry. This is because these industries are using modularity of products. based on lots of previous studies and information overload theory, we made two hypothesis and verify with empirical analysis. All 108 data were used. We used the R program and SPSS program for statistical verification. Results - As a result of the study, modularization of products showed positive relationship with customer satisfaction to a certain level. However, it has been found that when the modularization is over and beyond a certain level, there is a negative relationship with customer satisfaction. Conclusions - Excessive modularization of products can have a negative impact on customer satisfaction. This result can be understood as a result of human limited rationality due to information overload. Therefore, it is important for companies to apply appropriate modularity to product design.

• The Journal of Korean Academy of Prosthodontics
• /
• v.40 no.1
• /
• pp.53-67
• /
• 2002

This study was aimed to analyze the stress distribution of implant and supporting tissue in single tooth implant restoration using Branemark $system^{(R)}$(Nobel Biocare, Gothenberg, Sweden) and Bicon system(Bicon Dental Implants, Boston, MA). Two dimensional finite element analysis model was made at mandibular first premolar area As a crown materials porcelain, ceromer, ADA type III gold alloy were used. Tests have been performed at 25Kgf vertical load on central fossa of crown portion and at 10Kgf load with $45^{\circ}$ lateral direction on cusp inclination. The displacement and stresses of implant and supporting structures were analyzed to investigate the influence of the crown material and the type of implant systems by finite element analysis. The results were obtained as follows : 1. The type of crown material influenced the stress distribution of superstructure, but did not influence that of the supporting alveolar bone. 2. The stress distribution of ceromer and type III gold alloy and porcelain is similar. 3. Stress under lateral load was about twice higher than that of vertical load in all occlusal restorative materials. 4. In Bicon system, stress concentration is similar in supporting bone area but CerOne system generated about 1.5times eater stress more in superstructure material. 5. In Branemark models, if severe occlusal overload is loaded in superstvucture. gold screw or abutment will be fractured or loosened to buffer the occlusal overload but in Bicon models such buffering effect is not expected, so in Bicon model, load can be concentrated in alveolar bone area.

• The KIPS Transactions:PartC
• /
• v.9C no.3
• /
• pp.313-322
• /
• 2002

In this paper, proposes Kerberos certification mechanism that improve certification service of PKINIT base that announce in IETF CAT Working Ggroup. Did to certificate other realm because search position of outside realm through DNS and apply X.509 directory certification system, acquire public key from DNS server by chain (CertPath) between realms by certification and Key exchange way that provide service between realms applying X.509, DS/BNS of PKINIT base. In order to provide regional services, Certification and key exchange between realms use Kerberos' symmetric method and Session connection used Directory service to connection X.509 is designed using an asymmetric method. Excluded random number ($K_{rand}$) generation and duplex encryption progress to confirm Client. A Design of Kerberos system that have effect and simplification of certification formality that reduce Overload on communication.

• Toxicological Research
• /
• v.31 no.1
• /
• pp.17-23
• /
• 2015

Excessive manganese (Mn) in the brain promotes a variety of abnormal behaviors, including memory deficits, decreased motor skills and psychotic behavior resembling Parkinson's disease. Hereditary hemochromatosis (HH) is a prevalent genetic iron overload disorder worldwide. Dysfunction in HFE gene is the major cause of HH. Our previous study has demonstrated that olfactory Mn uptake is altered by HFE deficiency, suggesting that loss of HFE function could alter manganese-associated neurotoxicity. To test this hypothesis, Hfe-knockout ($Hfe^{-/-}$) and wild-type ($Hfe^{+/+}$) mice were intranasally-instilled with manganese chloride ($MnCl_2$ 5 mg/kg) or water daily for 3 weeks and examined for memory function. Olfactory Mn diminished both short-term recognition and spatial memory in $Hfe^{+/+}$ mice, as examined by novel object recognition task and Barnes maze test, respectively. Interestingly, $Hfe^{-/-}$ mice did not show impaired recognition memory caused by Mn exposure, suggesting a potential protective effect of Hfe deficiency against Mn-induced memory deficits. Since many of the neurotoxic effects of manganese are thought to result from increased oxidative stress, we quantified activities of anti-oxidant enzymes in the prefrontal cortex (PFC). Mn instillation decreased superoxide dismutase 1 (SOD1) activity in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice. In addition, Hfe deficiency up-regulated SOD1 and glutathione peroxidase activities. These results suggest a beneficial role of Hfe deficiency in attenuating Mn-induced oxidative stress in the PFC. Furthermore, Mn exposure reduced nicotinic acetylcholine receptor levels in the PFC, indicating that blunted acetylcholine signaling could contribute to impaired memory associated with intranasal manganese. Together, our model suggests that disrupted cholinergic system in the brain is involved in airborne Mn-induced memory deficits and loss of HFE function could in part prevent memory loss via a potential up-regulation of anti-oxidant enzymes in the PFC.

• Korean Journal of Veterinary Research
• /
• v.39 no.4
• /
• pp.679-688
• /
• 1999

The combined effects of iron and selenium status on glutathione peroxidase (GSHPx) activity, cytochrome P-450 activity, and lipid peroxidation in the liver and intestinal mucosa of rats were investigated. In experiment one, four experimental groups (+Se+Fe, -Se+Fe, +Se++Fe, -Se++Fe) were manipulated for 3 weeks with intramuscular administration of irondextran (++Fe) and/or normal diet (+Fe) and deionized water (-Se) and/or selenium-supplemented deionized water (+Se). In experiment two, 2% dietary carbonyl iron (instead of the parenteral administration) was fed for 3 weeks to rats. Body weight of rats was significantly decreased in both parenterally and orally iron-overloaded groups (p<0.01), regardless of Se supplement. Serum iron was significantly increased in parenterally iron-overloaded groups but it was marginally increased in orally iron-overloaded groups. There was no significant difference in hemoglobin content among experimental groups in either experiment one or two. Total iron in the small intestine, intestinal mucosa, and livers was significantly high in both parenterally and orally iron-overloaded rats, regardless of selenium status. In the liver and intestine, GSHPx activity was significantly higher in all selenium-supplemented groups, compared to Se-deficient groups (p<0.01) and lipid peroxidation was significantly enhanced in both parenterally and orally iron-overloaded groups, compared to iron-adequate groups. There was no significant difference in cytochrome P-450 activity in the livers between groups in both experiment one and two. These results indicated that GSHPx activity in liver and intestinal mucosa was depended on selenium status, regardless of iron status, and iron-overload enhances lipid peroxidation in liver and intestinal mucosa by increasing the tissue iron content.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.1
• /
• pp.17-25
• /
• 2018

Recently, with the development of ICT technology and the rapid spread of smart devices, a huge amount of information is being generated. The recommendation system has helped the informant to judge the information from the information overload, and it has become a solution for the information provider to increase the profit of the company and the publicity effect of the company. Recommendation systems can be implemented in various approaches, but social information is presented as a way to improve performance. However, no research has been done to utilize trust cluster information among users in the recommendation system. In this paper, we propose a method to improve the performance of the recommendation system by using the influence between the intra-cluster objects and the information between the trustor-trustee in the cluster generated in the online review. Experiments using the proposed method and real data have confirmed that the prediction accuracy is improved than the existing methods.

• Asia pacific journal of information systems
• /
• v.26 no.2
• /
• pp.322-337
• /
• 2016

Research on information systems and software engineering has often neglected behavioral effects, which may play a role in decision making on software development. The current study addresses this issue by empirically investigating the behavioral roots of over-requirement in the context of a software development project via an experiment. The negative phenomenon of over-requirement refers to specifying a software system beyond the actual needs of the customer or the market, which overload the system with unneeded features. The research question addressed here is whether over-requirement is due in part to the emotional involvement of developers with the software features they developed because of behavioral effects. Previous studies have demonstrated that under the endowment, I-designed-it-myself, and IKEA effects, people become emotionally involved and overvalue physical items that they respectively possess, self-design, or self-create. The findings of our experiment show that participants over-valued features they were assigned to be responsible for, to specify, or to construct, thereby confirming that the three behavioral effects play a role in software development decisions and affect over-requirement. Thus, the study contributes to software development research and practice from the behavioral economics perspective, highlighting the roots of over-requirement.

• Journal of Korea Trade
• /
• v.26 no.3
• /
• pp.1-22
• /
• 2022

Purpose - Social media platforms have presented individuals with an opportunity to create and maintain their social relationship through the use of social media services. However, such social relationship has a negative influence on users' interest in social media. Design/methodology - Using structural equation modeling, this study seeks to examines the effects of different social media conflicts (individual and social conflicts) on users' psychological internal state, especially user apathetic behavior Findings - The findings confirm that, among social media conflicts, social-related conflict, especially social interaction overload has a negative effect on cognitive resonance, while individual conflict has the highest effect on cognitive dissonance. Also, cognitive dissonance has a much greater effect than cognitive resonance on user resistance, this means that users' negative perception of social media has a greater influence on their resistance. Lastly, user's resistance was found to have a positive influence on user's apathetic behavior. Originality/value - In other to capture social media Apathetic behavior, this study focus on social media conflict perspective, which includes social-related conflict and individual conflict, which are found to influence users' internal states towards social media and further induce social media behavior. This study is unique because it is among the first to explore social media apathetic behavior by focusing on the influence of both external social media conflict and internal state. Also, this study proposed that social related conflict has a higher negative influence on WeChat user than individual related conflict.

• Korean Journal of Social Welfare Studies
• /
• v.42 no.4
• /
• pp.187-216
• /
• 2011

This study examined the effects of elderly care facility social workers' work environment (role conflict, role ambiguity, role overload, and adequacy of the reward system) and personal tendency (emotional empathy, cognitive empathy, external attribution, and internal attribution) on their burnout (emotional burnout, low personal achievement, and depersonalization about clients) and suggested strategies for preventing burnout in social workers at elderly care facilities. For this purpose, we conducted a questionnaire survey of social workers working at institutions designated as elderly long-term care facilities and collected a total of 312 questionnaires. According to the results of analyzing the data using a structural equation model, among the sub-factors of work environment, role ambiguity had a significant positive effect on low personal achievement and depersonalization about clients, role conflict on emotional burnout, and role overload on depersonalization about clients. Among the sub-factors of personal tendency, cognitive empathy and internal attribution had a significant negative effect on low personal achievement, and external attribution had a significant positive effect on emotional burnout and depersonalization about clients. This study is meaningful in that it illuminated social workers' burnout not only from the aspect of work environment but also from that of personal tendency.