• Journal of the Korean association of regional geographers
• /
• v.2 no.1
• /
• pp.151-164
• /
• 1996

The regional division by the characteristics of the drainage patterns is important to understand its physical environment comprehensively, because the drainage network develops in reflecting characteristics of geological, geographical and climatical features in the drainage basin keenly. This study is the attempt to divide physical region in China whose drainage pattern is diverse. Chinese drainage basin is mainly divided into the interior drainage basin and the peripheral drainage basin. The interior drainage basin is divided into (1)the deranged pattern and (2)the centripetal pattern. The peripheral drainage basin is divided into (1)the dendritic pattern, (2)the parallel pattern, (3)the radial pattern and (4)the anastomatic pattern. Drainage patterns of the interior drainage basin are formed by affecting geographical features and climatic conditions mainly. In the peripheral drainage basin, drainage patterns are formed by other factors: the parallel pattern is connected with geological structure lineament by tectonic movement, the radial pattern with changes of the river channel resulted from the Yellow River's overflow, the anastomotic pattern with human's activities. The distributional features of the physical region in China are as follows: The deranged pattern appears in Zangbai Plateau, the centripetal pattern does in arid basin of the northwest China. the parallel pattern does in Hengduan mountains affected strongly by tectonic movement between Yangtze paraplatform and Indian Plate, does in the upper stream of Yangtze River and Ganges River in the south of Qinghai-Xizang Plateau, the radial pattern in Huaihe Haihe River drainage basin appearing in the alluvial fan region of Yellow River's downstream and the anastomotic pattern does in the delta of Yangtze River, in the northern coastal plain of the Jiangsu-Province and in the delta of Zhujiang River. Except these areas in the peripheral drainage basin, the dendritic pattern is usually found in the other areas.

• Journal of Korea Spatial Information System Society
• /
• v.5 no.2 s.10
• /
• pp.55-68
• /
• 2003

NGIS projects have been widely proceeded by the central and municipal governments, and the higher cost for proceeding the NGIS projects emphasizes the importance of the data sharing among related agencies. For supporting data sharing, effective data generation, and management. 'THE GUIDELINE FOR MANAGING AND DOCUMENTING GEOGRAPHIC INFORMATION CATALOGUES' has been established and enforced since the year 2002. Although metadata for distributing geographic information through the NGIS distribution network has already been installed, this needs to be complimented to maximize the data utilization. Based on such requirements, a draft standard of the national metadata which is compliant with the ISO 19115 has been proposed from this study. All components of the metadata for distributing geographic information have been included and related metadata items for the management purpose have been derived from domestic and foreign studies. Based on this, draft national metadata standards comprised of 13 sections have been made. The metadata standards from this study could contribute to building basic standards to access and to utilize geographic information in various application field. This would also be fundamental base for activating GIS in public and private sectors.

• Journal of KIISE:Information Networking
• /
• v.29 no.3
• /
• pp.253-264
• /
• 2002

Recently, hierarchical architectures of databases for location management have been proposed in order to accommodate the increase in user population in future personal communication systems. In particular, a 3-level hierarchical database architecture is compatible with current cellular mobile systems. In the architecture, a newly developed additional databases, regional location database(RLR), are positioned between HLR and VLRs. We propose an efficient cache scheme, called the Double T-thresholds Location Cache Scheme. The cache scheme extends the existing T-threshold location cache scheme which is competent only under 2-level architecture of location databases currently adopted by IS-41 and GSM. The idea behind our scheme is to use two pieces of cache information, VLR and RLR serving called portables. The two pieces are required in order to exploit root only locality of registration area(RA) but also locality of regional registration area(RRA) which is the wide area covered by RLR. We also use two threshold values in order to determine whether the two pieces are obsolete. In order to model the RRA residence time, the branching Eralng-$\infty$ distribution is introduced. Our minute cost analysis shows that the double T-threshold location cache scheme yields significant reduction of network and database costs for molt patterns of portables.

• Journal of the Korean Society of Food Culture
• /
• v.26 no.3
• /
• pp.220-229
• /
• 2011

This study attempted to understand the perception and the degree of trust that consumers had in the national agricultural food accreditation system, to inquire into and examine the consumers' perception of traditional food quality certification performed for the protection of excellent traditional food, and to propose the right direction for the policies on the traditional food quality certification system and the plans to improve consumers' perception of the system. According to the results of this survey performed in married women, based on the 'the recognition of accreditation system' and 'the recognition of certification marks' of 'the seventh national agricultural food accreditation system' presently being used by the Ministry for Food, Agriculture, Forestry and Fisheries, the household food purchasers showed high recognition for eco-friendly agricultural product accreditation, processed food KS certification, and organically processed food certification in that order. Meanwhile, it was shown that they indicated low recognition for the traditional food-related accreditation systems such as 'traditional food quality certification' and 'food grand master'. It was found that reliability of the certification mark provided by the agricultural food accreditation system gained 3.54 points (on a 5-point scale), and 68.1% of the study subjects referred to the certification marks while purchasing agricultural foods. And most of them answered to the question of 'why they referred to the certification marks' saying that it was done 'to choose safe food'. The most frequent answer to question of 'the means to recognize the traditional food quality certification system' was 'broadcasting, advertising'. 57.3% of the subjects had a previous experience of buying a product certified by the traditional food quality certification system, and 93.2% of all the subjects had the intention to buy a product certified by the traditional food quality certification system later. And most of them answered that 'strengthening government policies' would be the most ideal way to inform the public of the traditional food quality certification system. According to the results of this study, while 'relying on the traditional food quality certification system in general' was relatively high among the consumers, 'intention to buy quality certified products by visiting a distantly located store' was low; thus, from this analysis, it can be seen that there is a need for diversification of places selling these quality certified products and to establish a distribution network for these products.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.6
• /
• pp.171-178
• /
• 2010

Pipeline structure is one of core underground infrastructure which transports primary sources. Since the almost pipeline structures are placed underground and connected each other complexly, it is difficult to monitor their structural health condition continuously. In order to overcome this limitation of recent monitoring technique, recently, a Ubiquitous Sensor Network (USN) system based on on-line and real-time monitoring system is being developed by the authors' research group. In this study, real-time pipeline health monitoring (PHM) methodology is presented based on electromechanical impedance methods using USN. Two types of damages including loosened bolts and notches are artificially inflicted on the pipeline structures, PZT and MFC sensors that have piezoelectric characteristics are employed to detect these damages. For objective evaluation of pipeline conditions, Damage metric such as Root Mean Square Deviation (RMSD) value was computed from the impedance signals to quantify the level of the damage. Optimal threshold levels for decision making are estimated by generalized extreme value(GEV) based statistical method. Throughout a series of experimental studies, it was reviewed the effectiveness and robustness of proposed PHM system.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.6
• /
• pp.185-195
• /
• 2017

In recent years, unexpected bridge fire accidents have increased because of augmenting the number of traffic volumes and hazardous materials by the increment in traffics and distribution business. Furthermore, in accordance with the effort of using the under space of bridges, the ratio of occupied by combustible materials like oil tanker or lorry has been increased. As a result, the occurrence of bridge fire has been growing drastically. In order to mitigate the accident of bridge fire, risk assessment of bridge fire has been studied, however, practical risk models considering safety from users' viewpoints were scarce. This study represented quantitative risk assessment model applicable to national road bridges in Korea. The primary factors with significant impacts on bridge fire accidents was chosen such as clearance height, materials of bridges, arrival time of fire truck and fire intensity. The selected factors were used for Fire Dynamics Simulation (FDS) and the peak temperature calculated by FDS in accordance with the fire duration and fire intensity. The risk assessment model in bridge fire reflected the FDS analysis results, the fire damage criteria, and the grade of fire truck arrival time was established. Response plans for bridge fire accidents according to the risk assessment output has been discussed. Lastly, distances between bridges and fire stations were calculated by GIS network analysis. Based on the suggested assessment model and methodology, sample bridges were selected and graded for the risk assessment.

• Journal of KIISE:Information Networking
• /
• v.33 no.4
• /
• pp.289-298
• /
• 2006

Algorithms for application-level multicast often use trees to deliver data from the source to the multiple receivers. With the tree structure, the throughput experienced by the descendant nodes will be determined by the performance of the slowest ancestor node. Furthermore, the failure of an ancestor node results in the suspension of the session of all the descendant nodes. This paper focuses on the transmission of data using multiple virtual forwarders, and suggests a scheme to overcome the drawbacks of the plain tree-based application layer multicast schemes. The proposed scheme elects multiple forwarders other than the parent node of the delivery tree. A receiver receives data from the multiple forwarders as well as the parent node and it can increase the amount of receiving data per time unit. The multiple forwarder helps a receiver to reduce the impact of the failure of an ancestor node. The proposed scheme suggests the forwarder selection algorithm to avoid the receipt of duplicate packets. We implemented the proposed scheme using MACEDON which provides a development environment for application layer multicast. We compared the proposed scheme with Bullet by applying the implementation in PlanetLab which is a global overlay network. The evaluation results show that the proposed scheme enhanced the throughput by 20 % and reduced the control overhead over 90 % compared with Bullet.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.11A
• /
• pp.1027-1034
• /
• 2005

IEEE802.15.4a, which is started to realize the PHY layer including high precision ranging/positioning and low data rate communication functions, requires a simple and low power consumable transceiver architecture. To satisfy this requirements, the simple noncoherent on-off keying (OOK) UWB transceiver with the parallel energy window banks (PEWB) giving high precision signal processing interface is proposed. The flexibility of the proposed system in multipath fading channel environments is acquired with the pulse and bit repetition method. To analyze the bit error rate (BER) performance of this proposed system, a noise model in receiver is derived with commonly used random variable distribution, chi-square. BER of $10^{-5}$ under the line-of-sight (LOS) residential channel is achieved with the integration time of 32 ns and signal to noise ratio (SNR) of 15.3 dB. For the non-line-of-sight (NLOS) outdoor channel, the integration time of 72 ns and SNR of 16.2 dB are needed. The integrated energy to total received energy (IRR) for the best BER performance is about $86\%$.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.4C
• /
• pp.333-341
• /
• 2002

This article is written to make a foundation for effective radio network engineering by enabling the accurate traffic assumption between Base Station (BTS : Base Station Transceiver Subsystem) md Repeater through the scientific and systematic analysis of mobile traffic dealt within CDMA Base Station. Among these, Repeater, having direct physical connection with BTS, simply does the remote relay function but the volume of the traffic flowed into the repeater is not accountable. The total BTS traffic is the sum of traffic dealt by the BTS and multiple Repeaters. In this article, we tried traffic analysis of this kind by adopting RTD (Round Trip Delay) which is specially designed to measure distribution of the distance between the Base Station and the Mobile station by differentiating the traffic dealt by BTS from traffic dealt by Repeaters. The fact that the connection between mobile station and BTS via Repeater (which is located remotely) yields far more delay than the direct connection between mobile station and BTS is the clue of this article. Based on this fact, Time Delay equipment was put at the receiving side of the Repeater to add certain amount of delay to the traffic to BTS and the result showed that the 99.78% of the traffic can be identified.

• Journal of Korea Water Resources Association
• /
• v.31 no.6
• /
• pp.821-832
• /
• 1998

This study investigates the prediction of daily water supply, which is a necessary for the efficient management of water distribution system. Fuzzy neuron, namely artificial intelligence, is a neural network into which fuzzy information is inputted and then processed. In this study, daily water supply was predicted through an adaptive learning method by which a membership function and fuzzy rules were adapted for daily water supply prediction. This study was investigated methods for predicting water supply based on data about the amount of water supplied to the city of Kwangju. For variables choice, four analyses of input data were conducted: correlation analysis, autocorrelation analysis, partial autocorrelation analysis, and cross-correlation analysis. Input variables were (a) the amount of water supplied (b) the mean temperature, and (c)the population of the area supplied with water. Variables were combined in an integrated model. Data of the amount of daily water supply only was modelled and its validity was verified in the case that the meteorological office of weather forecast is not always reliable. Proposed models include accidental cases such as a suspension of water supply. The maximum error rate between the estimation of the model and the actual measurement was 18.35% and the average error was lower than 2.36%. The model is expected to be a real-time estimation of the operational control of water works and water/drain pipes.