• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1444-1455
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• 1999

In the standard location strategy such as IS-41 and GSM, Home Location Register(HLR) and Visitor Location Register(VLR) databases are used to manage the location of mobile terminals. The primary goal that location management schemes investigate is to reduce the cost of database access and the traffic for signaling network. When mobile terminals move frequently, one of problems in the standard location management scheme is that HLR database is highly updated and the traffic in signaling network can be occurred significantly due to high message transfer rate between HRL and VLR. As a solution to these problems, this paper proposes the location management scheme using VLR Gateway(VG) to reduce the both traffics of HLR update and signaling network which are resulted from location registration requirements of mobile terminals whenever they cross their registration area boundary. VG is a kind of database that is placed between HLR and VLR. It integrates one or more registration area defined in a system into one group and plays a role on behalf of HLR in a integrated registration scope so that the call delivery and the movement of mobile terminals are possible without HLR access in the scope. In order to evaluate performance of IS-41 and proposed scheme, we simulate two schemes based on wide range of call to mobility ratio. Its experiment result shows that in the proposed scheme total database cost increased slightly whereas HLR and signaling traffic decreased remarkably.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1437-1443
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• 2016

Background: We investigated four factors, height, weight gain since age 20, physical activity, and alcohol drinking, for associations with risk of breast cancer (BC) according to menopausal status, using the latest data of the Japan Collaborative Cohort Study (JACC Study). Materials and Methods: We confined the analysis to 24 areas available of cancer incidence information, excluding women with a previous diagnosis of BC. Baseline data were collected from 38,610 (9,367 premenopausal, and 29,243 postmenopausal) women during 1988 and 1990. The study subjects were followed-up at the end of 2009, and 273 (84 premenopausal, and 189 postmenopausal) cases of BC were newly diagnosed in 501,907 person-years. The Cox model was used to estimate a hazards ratio (HR) and its 95% confidence interval (CI) of BC risk. Results: As a result of the multivariate analysis adjusting for age at baseline survey, age at menarche, number of live births, and, age at first delivery, weight gain since age 20 of 6.7 kg-9.9 kg, and ${\geq}10.0kg$ were significantly associated with increased risk for postmenopausal BC (HR=2.48, 95% CI 1.40-4.41, and, HR=2.94, 95% CI 1.84-4.70, respectively). Significantly increased trend of BC risk was also observed in weight gain since age 20 (p for trend, p<0.001). Amount of ethanol intake per day${\geq}15.0g$ was significantly associated with increased risk for postmenopausal BC in the multivariable-adjusted analysis (HR=2.74, 95% CI 1.32-5.70). Conclusions: Higher weight gain in adulthood and larger amounts of ethanol intake were significantly associated with increased risk of BC in Japanese postmenopausal women. None of the investigated factors were significantly associated with BC risk in Japanese premenopausal women.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7749-7754
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• 2015

Background: Currently, cationic liposome has become the commonly used vehicles for gene transfection. Furthermore, one of the most significant steps in microRNAs expression studies is transferring microRNAs into cell cultures successfully. In this study we aim to approach the feasibility of transfection of cervical cancer cell lines mediated by liposome and to obtain the optimized transfection condition for cervical cancer cell lines. Materials and Methods: $Lipofectamine^{TM}2000$ as the carrier, miR-101 mimic was transfected into Hela cells and Siha cells. Using green fluorescent protein as reporter gene, to set different groups according to cell seeding density, the amount of miRNA, miRNA and the proportion of Liposomes, Whether to add serum into medium to study their impact on the liposomal transfection efficiency. Finally, MTT assay was used to analyze the relative minimal cell toxicity of liposome reagents. Results: The seeding density of Hela cell line and Siha are $1.5{\times}10^4$ (per well of 24 well plates), miRNA amount is 1ul of both, the ratio of miRNA and liposome is 1:0.5 of Hela cell line; 1:0.7 of Siha cell line respectively, after 24 hours we can get the highest transfection efficiency. Compared with serum medium, only Siha cells cultured with serum-free medium obtained higher transfection efficiency before transfection (P<0.01). MTT assay showed that according to the above conditions which has the lowest cytotoxicity. Conclusions: The method of Liposome to transfected is a suitable way and it can be an efficient reagent for miRNA delivery for Hela cells and Siha cells in vitro. It may serve as a reference for the further research or application.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.34-43
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• 1977

This study attempts to examine the performances of Myun Health Workers-the frontline workers in the Korean rural health care delivery system. The time-activity approach was mainly utilized as a measuring tool. This study was undertaken in September 1976 with 35 Myun Health Workers at the Kang Wha County. The pretested time-activity approach sheets were filled out daily for one month by those Myun Health Workers themselves. Statistical means and variances of analysis were utilized for statistical method in comparing some activities and functions converged into time distribution Findings: 1. The workers's average working hours derived in this study is 8 hours and 48 minutes per day, which takes half an hour longer than normal schedule. 2. They spend 56% working hour for direct services, in other words, the main function, 22% for supportive function, and 22% for other activities, the unrelated health services. 3. Considering the total working hours of main function, out-center activity is far more than in-center services with the ratio of 70% to 30% respectively, which proves, therefore, that the main activity of the workers is home visiting. 4. It takes 20 minutes purely for home visiting and takes 14 minutes for transportation. 5. This research also indicates that such factors as characteristics of the health workers and myun influence in shaping the structures of the worker's function and activity: a. The workers whose working site is located in myun office spend 15% among total working hours in carring out official myun activities, which is incidentally unrelated to health services, while the health subcenter have no rooms for administrative jobs for myun office. b. The workers whose office is in health subcenter contribute much time in doing main function and those working in special project distribute more time in performing supportive function. c. The types of workers are another dominant factor to influence the components of worker's functions and activities. MCH workers and MPW I spend much time for manipulating main function. d. MPW II, whose function is reorganized by special project in 2 myuns shows different pattern of time distribution compared to the TB worker orFP worker in the ordinary area. MPW II distributes their time evenly in performing MCH program, T.B. Program, F.P. program and education activity, while the unipurpose workers engage in carring out only their dominant role. e. Another variables which involve the variation of the worker's activity can be illustrated with the variables like target population, size of myun and convenience for transportation, among which the latter two are remarkable factors in determining the time for out-center service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.5
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• pp.555-564
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• 2016

This paper proposes a time slot allocation scheme for military patrol environments. This proposal comes from analysis of traffic properties in a military patrol environment. In the near future, robots are expected to explore enemy grounds and measure threat, taking the place of human patrol. In order to control such robots, control messages must be extremely accurate. One mistake from the control center could cause a tragedy. Thus, high reliability must be guaranteed. Another goal is to maintain a continual flow of multimedia data sent from patrol robots. That is, QoS (Quality of Service) must be guaranteed. In order to transmit data while fulfilling both attributes, the per-path based centralized TDMA slot allocation scheme is recommended. The control center allocates slots to robots allowing synchronization among robots. Slot allocation collisions can also be avoided. The proposed scheme was verified through the ns-3 simulator. The scheme showed a higher packet delivery ratio than the algorithm in comparison. It also performed with shorter delay time in the downlink traffic transmission scenario than the algorithm in comparison.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.41-46
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• 2004

The influence of pollutant loads on the water quality in Jeongeupcheon of Dongjin river was evaluated from Jan. 2002 to Dec. 2003 for two years. The range of pH in water was $6.87{\sim}7.53$. The EC level in upstream ranged from 83 to $95\;{\mu}s/cm$ with the highest value in autumn. The BOD level in upstream rang ed from 0.61 to 1.27 mg/L, which would be I grade according to water quality criteria by Ministry of Environment, but that in downstream was III grade. The average T-N level in midstream ranged from 6.10 to 10.84 mg/L which was the highest values throughout the stretch of the river. The average T-P levels ranged from. 0.41 to 0.98 mg/L Jeongeupcheon was suitable for the agricultural usage based upon one year analysis of river water quality. The effluent loads of BOD was high in midstream (J4) with 553 kg/day. The major sources of T-N loads were livestock, population, land use, and industry in order. The effluent loads of T-N was high in J4 by population and industry while that of T-N was high in J5 and J6 by livestock and land use. The delivered loads of T-N was high in downstream The delivered loads of T-P was low as compared with those of BOD and T-N. The delivery ratio of T-N ranged from 6 to 38%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.146-170
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• 2017

Joint channel assignment and routing is a well-known problem in multi-radio wireless mesh networks for which optimal configurations is required to optimize the overall throughput and fairness. However, other objectives need to be considered in order to provide a high quality service to network users when it deployed with high traffic dynamic. In this paper, we propose a re-configuration optimization model that optimizes the network throughput in addition to reducing the disruption to the mesh clients' traffic due to the re-configuration process. In this multi-objective optimization model, four objective functions are proposed to be minimized namely maximum link-channel utilization, network average contention, channel re-assignment cost, and re-routing cost. The latter two objectives focus on reducing the re-configuration overhead. This is to reduce the amount of disrupted traffic due to the channel switching and path re-routing resulted from applying the new configuration. In order to adapt to traffic dynamics in the network which might be caused by many factors i.e. users' mobility, a centralized heuristic re-configuration algorithm called State-Aware Joint Routing and Channel Assignment (SA-JRCA) is proposed in this research based on our re-configuration model. The proposed algorithm re-assigns channels to radios and re-configures flows' routes with aim of achieving a tradeoff between maximizing the network throughput and minimizing the re-configuration overhead. The ns-2 simulator is used as simulation tool and various metrics are evaluated. These metrics include channel-link utilization, channel re-assignment cost, re-routing cost, throughput, and delay. Simulation results show the good performance of SA-JRCA in term of packet delivery ratio, aggregated throughput and re-configuration overhead. It also shows higher stability to the traffic variation in comparison with other compared algorithms which suffer from performance degradation when high traffic dynamics is applied.

• Journal of Korean Society of Steel Construction
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• v.26 no.4
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• pp.299-309
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• 2014

HSA800 is a new high strength steel (HSS) plate for building structures developed by POSCO and RIST in 2011. It has upper and lower bounds for yield ($F_y$) and tensile ($F_u$) strength as of 650-770MPa and 800-950MPa, respectively, with yield ratio ($F_y/F_u$) limit as of 0.85 which make steel quality more reliable and enhance the seismic resistance of structures. As made by TMCP, it has a good weldability without increasing carbon percentage. The objective of this study is to provide alternative design of mega-structural members of the Lotte World Tower (555m, 123 story), a first super-tall building in Korea, using HSS considering structural safety, constructability, and cost-effectiveness. Steel outrigger trusses, belt-trusses and steel exterior columns were selected and analyzed to evaluate the structural performance between original and alternative designs using HSS. The results show that HSS can be applied to the members which do not affect lateral stiffness of a building and, in this study, approximately 1100tons of steel were saved. It implies that HSS can save overall construction costs - manufacturing, delivery, and erection costs - by reducing mega structural member size. HSA800 was very first applied to the Lotte World Tower based on the results of this study.

• Journal of Internet Computing and Services
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• v.16 no.2
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• pp.117-125
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• 2015

The information about protein structure gives the clues for the function of protein. It is needed for the improvement for the efficacy and fast development of protein drugs. So, the studies visualizing the structure of protein effectively increase. Most studies of visualization focus on the structural prediction for protein or the improvement on the rendering speed. However, studies of information delivery depending on the form of protein visualization are very limited. The major objective of this study is to analyze the information representation goodness-of-fit for the patterns of the hybrid visualization with primary and secondary structures of protein. Those hybrid visualizations included the patterns which updated current representative visualization services, Chimera, PDB and Cn3D. Information factor to analyze information representation goodness-of-fit is assorted by protein primary structure, secondary protein structure, the location of amino acid and ratio information about protein secondary structure, based on the result of subject-analysis. Subject is the group of experts who are involved in protein drug development over 5 years. The result of this study shows the meaningful difference in the information representation goodness-of-fit by the patterns of hybrid visualization and proves the difference in the information by the pattern of visualization.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.10
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• pp.691-699
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• 2014

In order to increase network lifetime, duty-cycle MAC protocols which can reduce energy consumption caused by idle listening is proposed for WSNs. In common duty-cycle MAC protocols, each sensor node calculates its duty-cycle interval based on the current amount of residual energy. However, in WSNs with the capability of energy harvesting, existing duty-cycle intervals based on the residual energy may cause the sensor nodes which have high energy harvesting rate to suffer unnecessary sleep latency. Therefore, a duty-cycle scheduling scheme which adjust the duty-cycle interval based on both of the residual energy and the energy harvesting rate was proposed in our previous work. However, since this duty-cycle MAC protocol overlooked the performance variation according to the change of duty-cycle interval and adjusted the duty-cycle interval only linearly, the optimal duty-cycle interval could not be obtained to meet application requirements. In this paper, we propose three methods which calculate the duty-cycle interval and analyse their results. Through simulation study, we verify that network lifetime, end-to-end delay and packet delivery ratio can be improved up to 23%, 44% and 31% as compared to the existing linear duty-cycle scheduling method, respectively.