• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.81-94
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• 2005

Recently, wireless LAN circumstance is being widely deployed in Public spots. Many People use Portable equipments such as PDA and laptop computer for multimedia applications, and also demand of mobility support is increasing. However, handoff latency is inevitably occurred between both APs when clients move from one AP to another. To reduce handoff latency. in this paper, we suggest WFH(Weighted Frequent Handoff) using effective data structure. WFH improves cache hit ratio using a new cache replacement algorithm considering the movement pattern of users. It also reduces unessential duplicate traffics. Our algorithm uses FHR(Frequent Handoff Region) that can change pre-authentication lesion according to QoS based user level, movement Pattern and Neighbor Graph that dynamically captures network movement topology.

• Journal of Internet Computing and Services
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• v.25 no.2
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• pp.29-38
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• 2024

After Transcatheter Aortic Valve Replacement (TAVR), comprehensive management of complications, including the need for Permanent Pacemaker Implantation (PPI), is crucial, increasing the demand for accurate prediction models. Departing from traditional image-based methods, this study developed an optimal PPI prediction model based on ECG data using the XGBoost algorithm. Focusing on ECG signals like DeltaPR and DeltaQRS as key indicators, the model effectively identifies the correlation between conduction disorders and PPI needs, achieving superior performance with an AUC of 0.91. Validated using data from two hospitals, it demonstrated a high similarity rate of 95.28% in predicting PPI from ECG characteristics. This confirms the model's effective applicability across diverse hospital data, establishing a significant advancement in the development of reliable and practical PPI prediction models with reduced dependence on human intervention and costly medical imaging.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.14-25
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• 2021

With the spread of COVID-19 and the government policy of social distancing, the demand for subways and buses is decreasing, whereas the demand for public bicycles and personal transportation is increasing. Hence, research is needed to understand the characteristics of this phenomenon and to prove the statistical reliability of the correlation between the subway and shared bicycle demands. In this study, the correlation between the number of confirmed COVID-19 cases and the replacement rate of subway and public bicycle demands was examined, but the statistical significance was not significant. However, during the period of September to December 2020, in which the number of confirmed COVID-19 cases in Seoul started to increase rapidly, there was a correlation between the number of confirmed COVID-19 cases and the replacement ratio. If the number of confirmed COVID-19 cases increases by more than a certain number, public bicycles are expected to play a significant role as alternates to the subways. It is expected that the role of public bicycles will increase, and that it is possible to suggest the direction of transportation operation and policy establishment for the continuation of COVID-19 countermeasures in field demonstration after elementary technology development. It is also expected that this study will suggest a direction for future development and policymaking.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.469-478
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• 2001

In the virtual memory system, page replacement policy exerts a great influence on the performance of demand paging. There are LRU(Least Recently Used) and LFU (Least Frequently Used) as the typical replacement policies. The LRU policy performs effectively in many cases and adapts well to the changing workloads compared to other policies. It however cannot distinguish well between frequently and infrequently referenced pages. The LFU policy requires that the page with the smallest reference count be replaced. Though it considers all the references in the past, it cannot discriminate between references that occurred far back in the past and the more recent ones. Thus, it cannot adapt well to the changing workload. In this paper, we first analyze memory reference patterns of eight applications. The patterns show that the recently referenced pages or the frequently referenced pages are accessed continuously as the case may be. So it is rather hard to optimize page replacement scheme by using just one of the LRU or LFU policy. This paper makes an attempt to combine the advantages of the two policies and proposes a new page replacement policy. In the proposed policy, paging list is divided into two lists (LRU and LFU lists). By keeping the two lists in recency and reference frequency order respectively, we try to restrain the highly referenced pages in the past from being replaced by the LRU policy. Results from trace-driven simulations show that there exists points on the spectrum at which the proposed policy performs better than the previously known policies for the workloads we considered. Especially, we can see that our policy outperforms the existing ones in such applications that have reference patterns of re-accessing the frequently referenced pages in the past after some time.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.77-86
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• 2013

This research was carried out to evaluate and raise the energy efficiency of wood frame house. The commercial solution program CE3 (Construction Energy Efficiency Evaluation) was used for simulating the energy consumption in the single-family wood frame house. The results showed that the annual heating energy demand of the house was 160 kWh per 1 $m^2$ floor area. In order to decrease the heating energy demand, the following energy efficiency methods were applied to the simulation : a) simplification of building shape, b) decrease of windows area, c) application of high performance windows (with low thermal transmittance) and d) application of heat recovery ventilator. In case of replacement of the windows with high performance one with thermal transmittance 1 $W/m^2{\cdot}K$, the lowest heating demand of 80 $kWh/m^2{\cdot}a$ was obtained. The best combination of methods, application of high performance windows and heat recovery ventilator, showed heating energy demand 34.5 $kWh/m^2{\cdot}a$.

• Journal of Dairy Science and Biotechnology
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• v.14 no.1
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• pp.43-56
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• 1996

The world dairy industry has been driving their dairy policy on the basis of the self-supportihg principle. With progressing the GATT negotiation, the objective production amount has been reduced to maintain the optimum level, which decreasing the extra supply and over-stock before the U.R talks. The Oceania countries, where has the price competition capability, are continually increasing the milk production amount. Even through the USA is trying to increase their production amount with new export policy, the U.S.S.R collapse-down caused to decrease the milk production in world-wide basis. Because the U.S.S.R produced the highest amount of milk in the world. Moreover Europe Union countries, which recorded the half amount of dairy products in the world was decreasing their milk production. Therefore, about 4% of shortage is encountering at major dairy production countries in the standpoint of supply and demand. The drastic increasement of foreign dairy product import affects the domestic dairy industry with raw milk replacement and new dairy food demands creation since 1995, the initial period of free import system. Now, the domestic dairy industry are facing the inevitable problems such as the correction of producting and processing system. First of all, our dairy industry should resettle down the dairy production structure on the basis of self-supply of raw milk and offer the accurate dairy food informations. We still need to improve the raw milk quality. Also, more efforts are needed to have proper raw milk price policy. General domestic policies including the settlement of raw milk supply and demand, the reliability of inspection system in raw milk, ideal raw milk price system, centralization of raw milk collection, specially separated dairy organization should be improved legally in our dairy industry.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1688-1696
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• 2020

The paradigm of Internet-of-things(IoT) systems is changing from a cloud-based system to an edge-based system to solve delays caused by network congestion, server overload and security issues due to data transmission. However, edge-based IoT systems have fatal weaknesses such as lack of performance and flexibility due to various limitations. To improve performance, application-specific hardware can be implemented in the edge device, but performance cannot be improved except for specific applications due to a fixed function. This paper introduces a edge-centric metamorphic IoT(mIoT) platform that can use a variety of hardware through on-demand partial reconfiguration despite the limited hardware resources of the edge device, so we can increase the performance and flexibility of the edge device. According to the experimental results, the edge-centric mIoT platform that executes the reconfiguration algorithm at the edge was able to reduce the number of server accesses by up to 82.2% compared to previous studies in which the reconfiguration algorithm was executed on the server.

• Ocean and Polar Research
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• v.43 no.2
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• pp.65-72
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• 2021

In order to evaluate the dissolved organic carbon (DOC) and fluorescent dissolved organic matter (FDOM), as indicators of organic matter in the coastal environments, we measured the concentrations of DOC, FDOM, and chemical oxygen demand (COD) in saline groundwater (Woljeong, Pyoseon, and Hwasun beaches) and coastal seawater (Haengwon, Gwideok, Pyoseon, and Yeongnak) in Jeju, Korea. The highest concentrations of DOC and COD in groundwater were found in Woljeong and Pyoseon, and those in coastal water were observed in Haengwon and Pyoseon, indicating that the higher concentrations of DOC and COD seem to be associated with saline groundwater-driven dissolved organic matter (DOM) and/or biogeochemical processes. According to origin and optical properties of DOM using FDOM as a tracer, proportion of humic-like FDOM, more refractory DOM, was relatively greater in the groundwater than in the coastal water. With regard to this result, there was no relationship between DOC and COD in groundwater, while DOC showed a good positive correlation (r² = 0.66) with COD in coastal water. This result indicates that COD as an indicator of assessment of DOM has a limitation in which it is difficult to quantify refractory DOM. Although DOC is a potential alternative to COD in the coastal environments, particulate organic carbon cannot be negligible due to relatively higher concentration compared to the open ocean. Therefore, the use of total organic carbon (TOC) as a replacement of COD in the coastal ocean is important, and the evaluation criterion of the TOC is necessary in order to evaluate of organic matter indicator in the various coastal environments.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.4
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• pp.383-396
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• 2000

Before the advent of early plastic or maxillofacial reconstructive surgery, facial features could only be replaced and mimicked by prosthetic, artificial means. Facial deformity or dysfunction, whether congenital or acquired by trauma or mutilating disease, has long been an area of constant research, development and innovation in many cultures of the world. One of the greatest contributors to the need for maxillofacial prosthetics has been physical conflict and warfare. The use of maxillofacial prostheses is not merely the replacement of a missing or disfigured aspect of the face, but the rehabilitation of that individual back into the society from which they originate. Rehabilitation includes the restoration of the person's self worth and confidence, not just physically but psychologically. In sixteenth century, Ambroise Pare, French military surgeon, first have tried many maxillofacial prosthetics for injured war soldiers with papier-mache, silver, gold and copper. According to patient's demand who lost their maxillofacial figures, maxillofacial personnel have increased and prosthetic's skill have been advanced all of the world. Over the last decade, there has been a very rapid development in technical possibilities to provide patients with facial prostheses retained by skin penetrating implants. This article will present overall history of maxillofacial prostheses and some background information on the materials used from the old world. And to overcome still many limitation of prosthetic, new minds and new ideas for technique and materials should be developed.

• Journal of agricultural medicine and community health
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• v.22 no.1
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• pp.75-83
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• 1997

The medical insurance system has been adopted in 1989. Since then, the utilization of medical care services has increased rapidly. It appears that the medical institution needs more nursing manpower such as nurses and nurse aides to meet an increased demand for medical care for the residents. However, the medical care clinics run by a medical practitioners has a more shortage of nursing manpower than hospitals. The purpose of this survey was to analyze the current employment status and to obtain an opinion on the improvement of utilization such as recruitment and retention of nursing manpower. The questionnaire sent to the private physician and the response rate was 28.7% ; 87 out of 300 physicians. 82.6% of the respondents employed nurses aides rather than nurses and an average number of employees per clinic was 2.5 persons. Most physicians had difficulties in recruiting nursing manpower. It took more than one month for replacement on average, therefore, they were suffering from giving good continual care for the patient and also high resignation of nursing personnel. The low wage, long working hours, hard work and lack of incentives are the biggest reasons for the difficulty in recruiting and retaining of the nursing personnel obtained for the clinics survey. The above mentioned problems would be solved in the near future by changing those difficulties. In the meantime, the private physicians are marking an effort to retain the nursing personnel by keeping a relationship of the private physician's cooperatives.