• Asia pacific journal of information systems
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• v.18 no.3
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• pp.123-145
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• 2008

Recently, as the information communication technology develops, the discussion regarding the ubiquitous environment is occurring in diverse perspectives. Ubiquitous environment is an environment that could transfer data through networks regardless of the physical space, virtual space, time or location. In order to realize the ubiquitous environment, the Pervasive Sensing technology that enables the recognition of users' data without the border between physical and virtual space is required. In addition, the latest and diversified technologies such as Context-Awareness technology are necessary to construct the context around the user by sharing the data accessed through the Pervasive Sensing technology and linkage technology that is to prevent information loss through the wired, wireless networking and database. Especially, Pervasive Sensing technology is taken as an essential technology that enables user oriented services by recognizing the needs of the users even before the users inquire. There are lots of characteristics of ubiquitous environment through the technologies mentioned above such as ubiquity, abundance of data, mutuality, high information density, individualization and customization. Among them, information density directs the accessible amount and quality of the information and it is stored in bulk with ensured quality through Pervasive Sensing technology. Using this, in the companies, the personalized contents(or information) providing became possible for a target customer. Most of all, there are an increasing number of researches with respect to recommender systems that provide what customers need even when the customers do not explicitly ask something for their needs. Recommender systems are well renowned for its affirmative effect that enlarges the selling opportunities and reduces the searching cost of customers since it finds and provides information according to the customers' traits and preference in advance, in a commerce environment. Recommender systems have proved its usability through several methodologies and experiments conducted upon many different fields from the mid-1990s. Most of the researches related with the recommender systems until now take the products or information of internet or mobile context as its object, but there is not enough research concerned with recommending adequate store to customers in a ubiquitous environment. It is possible to track customers' behaviors in a ubiquitous environment, the same way it is implemented in an online market space even when customers are purchasing in an offline marketplace. Unlike existing internet space, in ubiquitous environment, the interest toward the stores is increasing that provides information according to the traffic line of the customers. In other words, the same product can be purchased in several different stores and the preferred store can be different from the customers by personal preference such as traffic line between stores, location, atmosphere, quality, and price. Krulwich(1997) has developed Lifestyle Finder which recommends a product and a store by using the demographical information and purchasing information generated in the internet commerce. Also, Fano(1998) has created a Shopper's Eye which is an information proving system. The information regarding the closest store from the customers' present location is shown when the customer has sent a to-buy list, Sadeh(2003) developed MyCampus that recommends appropriate information and a store in accordance with the schedule saved in a customers' mobile. Moreover, Keegan and O'Hare(2004) came up with EasiShop that provides the suitable tore information including price, after service, and accessibility after analyzing the to-buy list and the current location of customers. However, Krulwich(1997) does not indicate the characteristics of physical space based on the online commerce context and Keegan and O'Hare(2004) only provides information about store related to a product, while Fano(1998) does not fully consider the relationship between the preference toward the stores and the store itself. The most recent research by Sedah(2003), experimented on campus by suggesting recommender systems that reflect situation and preference information besides the characteristics of the physical space. Yet, there is a potential problem since the researches are based on location and preference information of customers which is connected to the invasion of privacy. The primary beginning point of controversy is an invasion of privacy and individual information in a ubiquitous environment according to researches conducted by Al-Muhtadi(2002), Beresford and Stajano(2003), and Ren(2006). Additionally, individuals want to be left anonymous to protect their own personal information, mentioned in Srivastava(2000). Therefore, in this paper, we suggest a methodology to recommend stores in U-market on the basis of ubiquitous environment not using personal information in order to protect individual information and privacy. The main idea behind our suggested methodology is based on Feature Matrices model (FM model, Shahabi and Banaei-Kashani, 2003) that uses clusters of customers' similar transaction data, which is similar to the Collaborative Filtering. However unlike Collaborative Filtering, this methodology overcomes the problems of personal information and privacy since it is not aware of the customer, exactly who they are, The methodology is compared with single trait model(vector model) such as visitor logs, while looking at the actual improvements of the recommendation when the context information is used. It is not easy to find real U-market data, so we experimented with factual data from a real department store with context information. The recommendation procedure of U-market proposed in this paper is divided into four major phases. First phase is collecting and preprocessing data for analysis of shopping patterns of customers. The traits of shopping patterns are expressed as feature matrices of N dimension. On second phase, the similar shopping patterns are grouped into clusters and the representative pattern of each cluster is derived. The distance between shopping patterns is calculated by Projected Pure Euclidean Distance (Shahabi and Banaei-Kashani, 2003). Third phase finds a representative pattern that is similar to a target customer, and at the same time, the shopping information of the customer is traced and saved dynamically. Fourth, the next store is recommended based on the physical distance between stores of representative patterns and the present location of target customer. In this research, we have evaluated the accuracy of recommendation method based on a factual data derived from a department store. There are technological difficulties of tracking on a real-time basis so we extracted purchasing related information and we added on context information on each transaction. As a result, recommendation based on FM model that applies purchasing and context information is more stable and accurate compared to that of vector model. Additionally, we could find more precise recommendation result as more shopping information is accumulated. Realistically, because of the limitation of ubiquitous environment realization, we were not able to reflect on all different kinds of context but more explicit analysis is expected to be attainable in the future after practical system is embodied.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.625-634
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• 2003

More than a decade after its initial proposal, deployment of IP Multicast has been limited due to the problem of traffic control in multicast routing, multicast address allocation in global internet, reliable multicast transport techniques etc. Lately, according to increase of multicast application service such as internet broadcast, real time security information service etc., overlay multicast is developed as a new internet multicast technology. In this paper, we describe an overlay multicast protocol and propose fast join mechanism that considers switching of the tree. To find a potential parent, an existing search algorithm descends the tree from the root by one level at a time, and it causes long joining latency. Also, it is try to select the nearest node as a potential parent. However, it can't select the nearest node by the degree limit of the node. As a result, the generated tree has low efficiency. To reduce long joining latency and improve the efficiency of the tree, we propose searching two levels of the tree at a time. This method forwards joining request message to own children node. So, at ordinary times, there is no overhead to keep the tree. But the joining request came, the increasing number of searching messages will reduce a long joining latency. Also searching more nodes will be helpful to construct more efficient trees. In order to evaluate the performance of our fast join mechanism, we measure the metrics such as the search latency and the number of searched node and the number of switching by the number of members and degree limit. The simulation results show that the performance of our mechanism is superior to that of the existing mechanism.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.6
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• pp.185-196
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• 2015

Energy aware server clusters aim to reduce power consumption at maximum while keeping QoS(Quality of Service) compared to energy non-aware server clusters. They adjust the power mode of each server in a fixed or variable time interval to let only the minimum number of servers needed to handle current user requests ON. Previous studies on energy aware server cluster put efforts to reduce power consumption further or to keep QoS, but they do not consider energy efficiency well. In this paper, we propose an energy efficient cluster management based on autonomous learning for energy aware server clusters. Using parameters optimized through autonomous learning, our method adjusts server power mode to achieve maximum performance with respect to power consumption. Our method repeats the following procedure for adjusting the power modes of servers. Firstly, according to the current load and traffic pattern, it classifies current workload pattern type in a predetermined way. Secondly, it searches learning table to check whether learning has been performed for the classified workload pattern type in the past. If yes, it uses the already-stored parameters. Otherwise, it performs learning for the classified workload pattern type to find the best parameters in terms of energy efficiency and stores the optimized parameters. Thirdly, it adjusts server power mode with the parameters. We implemented the proposed method and performed experiments with a cluster of 16 servers using three different kinds of load patterns. Experimental results show that the proposed method is better than the existing methods in terms of energy efficiency: the numbers of good response per unit power consumed in the proposed method are 99.8%, 107.5% and 141.8% of those in the existing static method, 102.0%, 107.0% and 106.8% of those in the existing prediction method for banking load pattern, real load pattern, and virtual load pattern, respectively.

• Journal of Chest Surgery
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• v.40 no.7 s.276
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• pp.480-484
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• 2007

Background: Major vascular injuries can jeopardize a patient's life or imperil limb survival. We performed this study to establish an optimal management plan for vascular injuries. Material and Method: We retrospectively reviewed 26 cases of vascular injury that were treated at Pusan National University Hospital from May, 1999 to September, 2004. The age and sex distribution, the locations and causes of vascular injury, the diagnostic tools, the degree of injuries, clinical manifestations, the treatment modality and complications were reviewed. Result: The mean age was 39.5 years (range: $12{\sim}86$) and the male to female ratio was 22 : 4. The injuries were in 6 descending thoracic aortas, 4 femoral arteries, 4 popliteal veins and so on. The causes of injury were iatrogenic in 8 cases, traffic accident in 7, stab injury in 6 and industrial accident in 5. The most commonly used diagnostic tools were CT and angiography. The degrees of arterial injury were pseudoaneurysm in 10 cases, partial severance in 5, complete severance in 3 and thrombosis in 3. The degrees of venous injury were partial severance in 6 cases, complete severance in 2 and arteriovenous fistula in 2. The clinical manifestations were absence of pulse in 8 cases, coldness in 7, chest pain in 6, swelling in 5, bleeding in 5 and so on. The most frequently used type of revascularization was graft interposition in 11 cases. Two arteriovenous fistulae were repaired by endovascular procedure. There was one case of mortality due to multi-organ failure after hemorrhagic shock, There were three major amputations, and two of them were due to delayed diagnosis and treatment. Conclusion: A system for the early diagnosis and treatment is essential for improving limb salvage and patient mortality. As a consequence of the widespread application of endovascular procedures, the incidence of iatrogenic injuries has recently increased. Educating physicians is important for the prevention of iatrogenic injury. Easy communication and cooperation for earlier involvement of a vascular surgeon is also an important factor.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.224-237
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• 1988

To determine the causes of and related factors to childhood injuries, the emergency room records and inpatient medical records were reviewed for 4,849 injured children out of 15,790 pediatric patients(<15 years old) who visited the emergency rooms of 3 university hospitals and 2 general hospitals in Taegu from 1 January to 31 December 1987. Out of total injured children, 54.675 were 3-8 years old and the male to female ratio of the total injured children was about 2:1. The leading causes of injury were falls and slips (29.1%) and traffic accident(28.2%). The frequency of injury was higher in May-October than the rest of months and 51.6% of the injuries occurred between 15 and 20 o'clock. Falls and slips took place most frequently at the stairway(25.7%). The most common interpersonal violence was inflicted injuries(85.6%) and there were 11 child rapes. Dog bites accounted for 67.6% of all biting injuries and it occured 2.9 times more in male than in female. CO intoxication was the most common cause of poisoning (45.3%) and scalding accounted for 85.2% of all burns. Common places of drownings were river (32.2%), swimming pool (22.6%) and construction site(19.3%). To prevent childhood injuries, it is recommended to eliminate the hazardous environmental factors, to provide safe playgrounds, to educate the children for safety from kindergarten and the general public through mass communication, to establish a strict safety standard for houses, public buildings and facilities, and playgrounds.

• Korean Security Journal
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• no.38
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• pp.7-32
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• 2014

This study is aimed to analyze problems of police budgetary execution and to suggest better ways for establishing effective budget implementation as well as legitimacy of securing budget in the field of police work. For this purpose, this paper analyzed the annual reports on police budgetary execution, from 2009 to 2012, conducted by National Assembly Budget Office. In result, most parts of the police budgetary execution were not satisfied with the audit standard, and especially in terms of management of budgetary execution, it showed 40% in inappropriateness. In addition, excessive and underestimate appropriation in the police budgetary execution, which happened frequently in other offices, was recorded on the second place. 10% of the amount of budget was executed for ordinance violence. Given results analyzed from each division, Transportation Division occupied 40% of the amount of related problems and all of types in the field did not meet the audit standard, thus it is required to manage budgetary execution effectively. In terms of Public Safety Division, the problem was related to budgetary allocation prior to execution, such as overlap in other works, excessive and underestimate appropriation, and inappropriate business plans. Director General for Planning and Coordination did not meet the standard of law system maintenance, Given the light of the result of analyzing programs, traffic safety and securing communication was the most problematic and support for police administration, crime prevention and protecting the disadvantaged, educating professional police officers, and establishment of policing infrastructure were required to be reformed in sequence. In order to resolve these problems, it is demanded to check budgetary execution and the process in business plans on a regular basis. Additionally, in case of using budget in inappropriate parts, tough penality including reduction of budget in related to the local police should be implemented to increase the importance of budgetary execution. Moreover, because of the fact that a part of problem of budgetary execution was originally caused by the budgetary allocation, it is advised to allocate police budget using the budget proposal of National Finance Act and Ministry of Strategy and Finance.

• The Journal of the Korea Contents Association
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• v.8 no.2
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• pp.195-204
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• 2008

With the growth of airline management, as well as computer and IT security, the international trade in this modern society has been rapidly increasing, Along with the advancing, airplanes have become a universal means of communication. However, the complications associated with airplane safety have also been brought up as a result, the most concerning of which is terrorism. One of the main counterplans for preventing terrorism is Ground security activities the core of Ground security activities is absolute safety for passengers in both passenger terminal and freight terminal. Subastral security refers to physical protection, proximity control and 100% security search and freight guarding of the passengers' possessions, and the personnel's duties to perform such jobs are be! coming more crucial. On the other hand, Airport security check has bee n gradually developing since the 1960's, when hijacking began to take place. Although the airports have been providing more safe and comfortable services to their customers, terrorism is still happening today. When Ground security activities is minute, the users feel displeasure and discomfort, yet considering solely their convenience can brings problems in achieving safety. Since the 9.11 terror in 2001, the idea of improving and strengthening airport security was reinforced and a considerable amount of estate is being spent today for invention and application of new technology. Various nations, including the United States, have been improving their systems of security through public services; public police department is actively carrying out their duties in airports as well. In San Francisco International Airport, private police department is in charge of collection of data, national events, VIP protection, law enforcement, cooperation within facilities, daily-based patrol and traffic control. Under guidance and supervision of national organizations, such as TSA, general police department interprets X-Rays, operates metal detectors, checks passports or IDs and observes reactions to explosives. Under these circumstances, studies about advancement of cooperation and duties of general police department and private police department necessitated: especially about private police department and their training for searching equipments, decrease in number of turn over rate, invention of technology and prior settlement in estate for security. The privacy of the public, who make up the major population of airport passengers, must also be minimized. In the following research, the activities of police departments in San Francisco International Airport will be analyzed in order to understand recent actions of the United States on airport security.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.6
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• pp.58-69
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• 2022

This study compares and analyses the impacts of holding domestic garden expos that will be fundamental for holding garden expos in the future. Satisfaction with the three sites of the 2013 Suncheon Bay International Gardening Expo, 2015 Seoul Gardening Expo, and 2022 Goyang International Flower Fair, as well as factors affecting the satisfaction in economic, social/cultural, environment/ecology, and operation aspects, were analyzed. As a result of the study, the satisfaction level of all three sites was high, with a value of 3.5 or higher. In particular, satisfaction with the 2013 Suncheon Bay International Gardening Expo was the highest. It was found that there was a difference between the satisfaction level of the 2013 Suncheon Bay International Gardening Expo and the 2015 Seoul Gardening Expo. As a regional festival, the 2013 Suncheon Bay International Garden Expo has acquired a high status due to the 'Suncheon Bay Garden' being designated as the first National Garden. It is thought that great satisfaction was obtained because economic, social, cultural, and environmental revitalization was achieved by matching the values of citizen participation and ecological conservation. As a result of the comparison of perception types affecting the satisfaction by garden fair, satisfaction at the 2013 Suncheon Bay International Gardening Expo and the 2015 Seoul Gardening Expo, it was found that both affected all four aspects. The 2022 Goyang International Flower Fair did not affect satisfaction in the operational aspect. This seems to be because the Goyang International Flower Fair is already a fixed local brand. As a result of analyzing the detailed factors of perception that affect satisfaction, the three target sites were commonly analyzed, including social and cultural factors, which attract cultural events, improve pride and affection for the region, and help educate children. In terms of environmental and ecological factors were analyzed as an inconvenience in life due to traffic congestion. It can be seen that it has the same meaning as the comparative analysis of the difference in factors on the satisfaction of the target site. There is no difference in the effect on satisfaction in terms of social·cultural, and environmental·ecological aspects, but there are differences in terms of economy and operation. Based on the analysis results of this study, to hold a domestic garden expo in the future, it is necessary to properly utilize "environmental" and "ecological" garden aspects that have potential values according to the region's characteristics to develop sustainable, eco-friendly tourism resources. In addition, values will be more apparent when cultural and artistic programs are planned to establish a differentiated identity in the host area and are appropriately used as a marketing means for a local fair. A well-planned local festival through communication with local residents can affect the image of the region and lead to the revitalization of the local communities by securing urban competitiveness along with the establishment of urban brands, so it can be said that local residents' participation and national or local organizations' cooperation is essential.