• Journal of Communications and Networks
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• v.4 no.4
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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.

• International Area Studies Review
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• v.18 no.3
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• pp.249-265
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• 2014

The international mobile roaming service has been provided for more than one decade, but high price of international mobile roaming service, which is represented as 'bill shock' is still of major concern in lots of countries including Korea. With understanding of the given price issues, the international organizations, such as OECD, EU, WTO, ITU have been conducting extensive analyses and studies to find suitable solutions and appropriate measures. In the case of EU regulate the international roaming charges and implement the regulation policy. OECD do not have a compelling regulation on roaming charges, but OECD request to member state to find the reasons of high roaming charges and its solution. WTO Council for Trade in Services is reviewing the international mobile roaming in terms of whether impede international trade in services. The purpose of this study is to review many different approaches in international organizations related to reducing international roaming service charges, to drive some regulatory policy directions for reducing roaming charges.

• Journal of the Korean Professional Engineers Association
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• v.34 no.5
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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.

• Journal of Veterinary Clinics
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• v.34 no.1
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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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• v.65 no.5
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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.

• Proceedings of the KSRS Conference
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• 2005.10a
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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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• v.43 no.4 s.136
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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.

• Journal of Industrial Technology
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• v.21 no.A
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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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• v.38 no.6
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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.

• Proceedings of the KIEE Conference
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• 2006.04b
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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.