• Journal of Communications and Networks
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• 제4권4호
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• pp.363-369
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• 2002

Towards the deployment of 3rd generation systems, Virtual Home Environment (VHE), stemming from 3GPP, appears to be a powerful concept advocating the provision and delivery of personalized services to roaming users across network and terminal boundaries. This paper aims to expose the pathway for materializing the VHE concept, via the specification, implementation and evaluation of a prototype. Core aspects for realizing the concept such as the business and roaming models are presented, while a VHE enabling architecture utilizing key technologies (OSA/Parlay, MExE, and USAT) is introduced. The proposed architecture has already been evaluated by performing an initial trial demonstration. Currently it is being extended to support VHE service provision to roaming users, an aspect to be addressed by the final trial.

• 국제지역연구
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• 제18권3호
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• pp.249-265
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• 2014

지난 10년 동안 국제모바일로밍서비스가 제공되어 왔으나, 그 요금수준은 여전히 높은 수준에 있다. 이러한 국제모바일로밍서비스 요금수준에 대한 인식이 국제적으로 확산됨에 따라 국제기구 등에서는 로밍요금에 대한 다양한 개선방향 및 정책을 제시하고 있다. EU의 경우 로밍 이용요금 상한선 등에 대한 규제정책을 시행하고 있으며, OECD의 경우 강제적인 규제정책은 가지고 있지 않으나, 높은 로밍 요금 원인분석 및 이러한 요금에 대한 해결책의 회원국에 강구를 요구하고 있다. WTO는 서비스 무역 이사회를 중심으로 국제서비스무역을 저해하는지에 대한 검토를 하고 있으며, ITU에서도 요금에 대한 권고(D.98) 제시를 통하여 문제를 해결하려고 하고 있다. 본고의 목적은 국제모바일로밍서비스에 대한 주요 국제기구의 논의사항을 살펴보고 이를 통한 우리나라가 취할 수 있는 요금인하를 위한 규제정책방향을 제시하는 데 있다.

• 기술사
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• 제34권5호
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• pp.69-72
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• 2001

The national 2G-3G roaming is emerging as one of essential and important issues In Korea in connection with the recent granting of 3G licenses. Accustomed to the current seamless coverage and superb quality of 2G networks, many subscribers have very high expectations of an equal or better service provisioning by 3G networks. However, it is very unlikely for 3G operators to successfully build their networks as comprehensive as the current 2G networks in the beginning of network implementation and commercial launch. Therefore,3G operators are seriously considering the national 2G-3G roaming in Korea. In this paper. 1 would like to discuss and present a technical implementation scheme and problems that need to be solved fer successfully realizing the national 2G-3G roaming.

• 한국임상수의학회지
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• 제34권1호
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• pp.34-38
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• 2017

The aims of the present study were to determine the weaning time for adoption of kittens, and to evaluate the fetal growth rate during pregnant in free-roaming cats. This study was conducted on three pregnant free-roaming cats (one feral cat and two stray cats). Radiography and ultrasonography were performed on the feral cat and on one of the stray cats. In the feral cat, fetal head diameter was measured once during pregnancy to determine the cesarean section (C-sec) time. In the stray cat, serial fetal head diameter was measured from capture to parturition. The body weight of the feral cat's kittens was measured from 4 weeks postpartum because of their wildness. That of the stray cats' kittens was measured immediately after birth. In the feral cat, scheduled C-sec was performed at predicted parturition day by measurement of head diameter, and six healthy kittens were delivered. The stray cats had five and six kittens by natural delivery, respectively. In the body weight gain of feral and stray cat's kittens, two female kittens of the feral cat lost weight rapidly after they were separated from their mother, so they were returned to their mother for 1 more week. After that, the female kittens grew up without difficulty. Body weight gain of the ten kittens born to the two stray cats consistently increased, by approximately 14 g every day, until they were adopted. The body weight of kittens born by natural delivery was on average 77.5 g greater than that of kittens born by C-sec. However, the gap decreased with time. During the stray cat's pregnancy, fetal head diameter increased by 0.042 cm every day. Maximum head size before parturition was 2.43 cm. These results indicate that the weaning time for adoption of kittens was 5-week-old postpartum.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.1053-1064
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• 2023

Melatonin, which is produced from tryptophan, exerts various biological functions, including the regulation of circadian rhythm, sedative agents, and antioxidant ability. Therefore, we conducted two experiments with early-weaned rats and pigs to investigate the antioxidant and sedative effects of melatonin. In the rat experiment, a total of 42 rats (21 days old) were used, and the antioxidant capacity was determined. Next, we used 120 early-weaned piglets (21 days old) to conduct a 5-week experiment to evaluate the reductive effect of melatonin on energy-wasting movement, including roaming and fight states. Dietary melatonin supplementation significantly improved growth in both rats and pigs compared to the control groups. Additionally, rats fed a melatonin-supplemented diet showed advanced antioxidant capacity with a decrease in hepatic malondialdehyde concentration compared to rats fed a basal diet. Moreover, dietary melatonin ingestion increased resting and feeding behaviors and reduced roaming and fight behaviors during Days 8-21 compared to the control diet group. Collectively, early weaned animals given dietary melatonin supplementation showed improved growth through upregulation of hepatic antioxidant capacity and minimization of energy-wasting behavior, including roaming and fight states, after pigs' social hierarchy establishment.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.341-344
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• 2005

Mobile IPv6(MIPv6) allows a Mobile Node to talk directly to its peers while retaining the ability to move around and change the currently used IP address. One of the major issues regarding the basic Mobile IPv6 protocol is related to the handover management of a mobile node. This paper proposes efficient approach for adaptation of MIPv6 sing context information in roaming environments. To investigate on a efficient and secure handover procedure, proposed approach method will give us the following advantages: (l)the intention of context is to reduce latency, packet losses and avoid re-initiation of signaling to and from mobile nodes,(2) FMIPv6 aims to reduce handover latency due to IP protocol operations as small as possible in comparison to the inevitable link switching latency.

• Parasites, Hosts and Diseases
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• 제43권4호
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• pp.135-139
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• 2005

We have observed the seropositive rate of Taenia solium cysticercosis in residents at Nabo Village, Tiandong County, Guangxi Zhuang Autonomous Region, China by enzyme linked immunosorbent assay. The village had been found to be a relatively high endemic area of porcine cysticercosis among roaming pigs. Of 202 persons examined four males aged 15, 25, 35 and 41 year-old exhibited absorbance (abs) at 0.18, 0.20, 0.35 and 0.55, respectively. In addition, two females whose ages were 35 and 39 years revealed specific antibody levels of abs 0.26 and 0.41 in their sera. Overall positive rate among the people was $2.97\%$. All of these persons agreed that they had ingested the pork infected with T. solium metacestode (TsM), while history of proglottid discharge was not noticed from all of them. Three males and one female complained of intermittent headache. Our findings reinforced not only that the prevalence of cysticercosis might be related with roaming pigs infected with TsM but also that behavioral and environmental practices in local community constituted risk factors for transmission of the infection.

• 산업기술연구
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• 제21권A호
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• pp.117-122
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• 2001

Currently, the VHE (suggested for global roaming user to provide personal service environment) implementation scenario is being proposed to realize 3G network requirements. However, developing VHE scenarios are focused on signal flow between node and network, and network and network. this case may result in weakness to protect subscriber's privacy in 3G network which commonly uses visited network. In this paper, we reanalyze a several VHE implementation scenarios for user profile protection, indicate a problem concerning user privacy, and finally, design a procedure to cope with vulnerability in VHE implementation scenario.

• ETRI Journal
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• 제38권6호
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• pp.1145-1152
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• 2016

Because the nodes in a wireless sensor network (WSN) are mobile and the network is highly dynamic, monitoring every node at all times is impractical. As a result, an intruder can attack the network easily, thus impairing the system. Hence, detecting anomalies in the network is very essential for handling efficient and safe communication. To overcome these issues, in this paper, we propose a rule-based anomaly detection technique using roaming honeypots. Initially, the honeypots are deployed in such a way that all nodes in the network are covered by at least one honeypot. Honeypots check every new connection by letting the centralized administrator collect the information regarding the new connection by slowing down the communication with the new node. Certain predefined rules are applied on the new node to make a decision regarding the anomality of the node. When the timer value of each honeypot expires, other sensor nodes are appointed as honeypots. Owing to this honeypot rotation, the intruder will not be able to track a honeypot to impair the network. Simulation results show that this technique can efficiently handle the anomaly detection in a WSN.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.296-297
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• 2006

This paper presents a method to optimize train radio communication network for train control (CBTC) or multimedia services. To determine the optimized distance between wayside radio stations in a radio communication network constructed along railway, radio frequency allocation and hand-over capability is studied in terms of radio communication cell coverage and roaming feasibility.