• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.1
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• pp.58-68
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• 2002

Recently as recognition to prevent nature disasters is reaching the climax, the most important job of government official is to provide information related to the prevention of nature disasters through the Web and to bring notice to prevent disaster under people. Especially, if the case of daily forest fire hazard index is provided within visualization on Web, people may have more chances to understand about forest fire and less damages by large scale of forest fire. Forest fire hazard index presentation system developed in this paper presents daily forest fire hazard index on map visually also provides the information related to it in text format. In order to develop this system, CBDP(Component Based Development Process) is proposed in this paper. This development process tries to emphasize the view of reusability so that it has lifecycle which starts from requirement and domain analysis and finishes to component generation. Moreover, The concept of this development process tries to reflect component based method, which becomes hot issue in software field nowadays. In the future, the component developed in this paper may be possibly reused in other Web GIS application, which has similar function to it so that it may take less cost and time to develop other similar system.

• Tunnel and Underground Space
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• v.33 no.3
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• pp.169-188
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• 2023

Fires in tunnels are characterized by higher temperature rise and higher maximum temperatures compared to ground fires. For this reason, countries such as the Netherlands and Germany have developed separate temperature-time curves for use in tunnel fires. Fires in tunnels cause damage to the tunnel lining, such as loss of section and deterioration of the material properties. This study reviewed the design concept of fire stability of structures, section loss due to spalling, changes in physicochemical and mechanical properties of tunnel lining materials, fireproofing materials for structure safety, and fire damage prediction models. In order to secure the stability of a structure against fire, it is necessary to identify the type of structure and the possible fire load at the design stage, identify the expected section loss and damage range, and prepare for such damage through fireproofing materials. In this study, we have summarized the matters that can be referred to in performing such a series of tasks and presented our opinions on them.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.546-555
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• 2014

The final aim of this study is to develop a biofiltration system integrated with plant vegetation for improving indoor air quality effectively depending on indoor space and characteristics. However, to approach this final goal, several requirements such as constant pressure drops (PDs) and soil moisture contents (SMCs), which influence the capacity design for a proper ventilation rate of biofiltration system, should be satisfied. Thus, this fundamental experiment was carried out to adjust a proper wind speed and to ensure a stabilization of initial SMCs within biofilter for uniform distribution of SMCs and PDs, and for normal plant growth, especially avoiding root stress by wind. Therefore, we designed horizontal biofliter models and manufactured them, and then calculated the ventilation rate, air residence time, and air-liquid ration based on the biofilter depending on three levels of wind speed (1, 2, and $3cm{\cdot}s^{-1}$). The relative humidity (RH) and PD of the humidified air coming out through the soil within the biofilter, and SMC of the soil and plant growth parameters of lettuce and duffy fern grown within biofilter were measured depending on the three levels of wind speed. As a result of wind speed test, $3{\cdot}sec^{-1}$ was suitable to keep up a proper RH, SMC, and plant growth. Thus, the next experiment was set up to be two levels of initial SMCs (low and high initial SMC, 18.5 and 28.7%) within each biofilter operated and a non-biofiltered control (initial SMC, 29.7%) on the same wind speed ($3cm{\cdot}sec^{-1}$), and measured on the RH and PD of the air coming out through the soil within the biofilter, and SMC of the soil and plant growth parameters of Humata tyermani grown within biofilter. This result was similar to the first results on RHs, SMCs, and PDs keeping up with constant levels, and three SMCs did not show any significant difference on plant growth parameters. However, two biofiltered SMCs enhanced dry weights of the plants slightly than non-biofiltered SMC. Thus, the stability of this biofiler system keeping up major physical factors (SMC and PD) deserved to be adopted for designing an advanced integrated biofilter model in the near future.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.1-11
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• 2013

This study investigated Chinese Laws on the kind of urban green spaces and the legal requirements for the green spaces of urban habitat and analyzed the specificities of them intending to provide basic data to suggest bringing in or not the relevant Chinese Laws to Korea. This study can be summarized as follows: First, the concept of Chinese urban green spaces(g.s.) classified by 5 kinds(park g.s., production g.s., protection g.s., attachment g.s., the others g.s.) placed the park and green spaces in the same category unlike the Korean urban green spaces that only distinguishes between park and green spaces. The Chinese Urban Park is classified by 4 kinds(composite park, community park, special park, linear park) at the 'Standard for urban green spaces classification' which is below in rank of the legal system. Second, in case of calculation for green spaces ratio of urban green spaces in China, the green rooftop landscaping area should not be included as a green spaces area except the rooftop of a basement or semi basement building to which residents have easy access. The green spaces requirements and compulsory secure ratio by 3 habitat kinds(habitat, small habit, minimum habitat) of when to act as a residential plan is regulated. Third, the green spaces system is obligated to establish at habitat green spaces plan and is specified to conserve and improve existing trees and green spaces. The green spaces ratio on reconstruction for old habitat is relaxed to be lower than for new habitat and a gradient of green spaces is peculiarly clarified. The details and requirements for establishment and the minimum area intending for each classes of the central green spaces(habitat park, children park, minimum habitat's green spaces) are regulated. Especially at a garden style of minimum habitat's green spaces, intervals between the south and north houses and a compulsory security for green spaces area classifying into two groups(closing type green spaces and open type green spaces) by a middle-rise or high-rise building are clarified. System of calculation for green spaces area is presented at a special regulation. Fourth, a general index(area/person) of public green spaces within habitat to achieve by 3 habitat kinds is determined, in this case, the index on reconstruction for a deterioration zone can be relaxed to be lower to the extent of a specified quantity. A location and scale, minimum width and minimum area per place of public green spaces are regulated. A space plot principle including adjacent to a road, greening area ratio against total area, security of open space and the shadow line boundary of sunshine are also regulated to intend for public green spaces. Fifth, the minimum horizontal distance between the underground cables and the surrounding greening trees are regulated as the considerable items for green spaces when setting up the underground cables. The principle to establish green spaces within public service facilities is regulated according to the kind of service contents. It shall be examined in order to import or not the special regulations that only exist in Chinese Laws but not in Korean Laws. The result of this study will contribute to gain the domestic landscape architect's' sympathy of the research related to Chinese urban green spaces laws requiring immediate attention and will be a good chance to advance into the internationalization of Korean Landscape Architectural Laws.

• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.469-478
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• 2003

Internet information search engines using web robots visit servers conneted to the Internet periodically or non-periodically. They extract and classify data collected according to their own method and construct their database, which are the basis of web information search engines. There procedure are repeated very frequently on the Web. Many search engine sites operate this processing strategically to become popular interneet portal sites which provede users ways how to information on the web. Web search engine contacts to thousands of thousands web servers and maintains its existed databases and navigates to get data about newly connected web servers. But these jobs are decided and conducted by search engines. They run web robots to collect data from web servers without knowledge on the states of web servers. Each search engine issues lots of requests and receives responses from web servers. This is one cause to increase internet traffic on the web. If each web server notify web robots about summary on its public documents and then each web robot runs collecting operations using this summary to the corresponding documents on the web servers, the unnecessary internet traffic is eliminated and also the accuracy of data on search engines will become higher. And the processing overhead concerned with web related jobs on web servers and search engines will become lower. In this paper, a monitoring system on the web server is designed and implemented, which monitors states of documents on the web server and summarizes changes of modified documents and sends the summary information to web robots which want to get documents from the web server. And an efficient web robot on the web search engine is also designed and implemented, which uses the notified summary and gets corresponding documents from the web servers and extracts index and updates its databases.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.3
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• pp.60-68
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• 2009

This work proposes a 10b 200MS/s 65nm CMOS ADC for high-definition video systems such as HDTV requiring high resolution and fast operating speed simultaneously. The proposed ADC employs a four-step pipeline architecture to minimize power consumption and chip area. The input SHA based on four capacitors reduces the output signal range from $1.4V_{p-p}$ to $1.0V_{p-p}$ considering high input signal levels at a low supply voltage of 1.2V. The proposed three-stage amplifiers in the input SHA and MDAC1 overcome the low output resistance problem as commonly observed in a 65nm CMOS process. The proposed multipath frequency-compensation technique enables the conventional RNMC based three-stage amplifiers to achieve a stable operation at a high sampling rate of 200MS/s. The conventional switched-bias power-reduction technique in the sub-ranging flash ADCs further reduces power consumption while the reference generator integrated on chip with optional off-chip reference voltages allows versatile system a locations. The prototype ADC in a 65nm CMOS technology demonstrates a measured DNL and INL within 0.19LSB and 0.61LSB, respectively. The ADC shows a maximum SNDR of 54.BdB and 52.4dB and a maximum SFDR of 72.9dB and 64.8dB at 150MS/S and 200MS/s, respectively. The proposed ADC occupies an active die area of $0.76mm^2$ and consumes 75.6mW at a 1.2V supply voltage.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.183-194
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• 2004

The existing management job of research expenses has been divided into three parts： budget planning, budget draw-up, and exact settlement of budget. However, it caused some problems. Under this current circumstance it is required to obtain research expenses steadily, to operate efficiently and to use them clearly to solve such problems. As a result of a study on data warehouse development process of existing system integration company (Inmon, IBM) to reflect current trend described above, data warehouse development process of Inmon uses systematic and gradual access as a classical development cycle method. It causes overlap and feedback to the previous step in the process of each step Is requested. And another problem that it is difficult to toil what function refers and corrects data because functions and data are separated during performing development process at data warehouse development process of IBM is caused. Integrated management data warehouse development process of research expenses in the enterprise environment which applies UML at planning and analysis step, design step and implement and test step is suggested in this paper. Information retrieval agent uses existing budget plan DB, budget draw-up DB and budget settlement DB to find out information that a user wants to know. Information retrieval agent collects and saves information at integration database and information integration agent extracts, transports, transforms and loads the data. Information integration agent reduces a user's efforts to access to a number of information sources and check each of them. It also screens out data that a user may not need. As a result, integrated management data warehouse development process of research expenses in the enterprise environment reflects a user's requirements as much as possible and provides various types of information to make a decision which is needed to establish the policy of research expense management. It helps an end user approach his/her desired analysis information quickly and get various data from the comprehensive viewpoint rather than the fragmentary viewpoint. Furthermore, as it integrated three systems into one, it is possible to share data, to integrate the system, to reduce operating expenses and to simplify supporting environment for the decision making.

• The KIPS Transactions:PartC
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• v.16C no.6
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• pp.791-800
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• 2009

Multicasting is fundamental to many ad hoc network applications requiring collaboration of multiple nodes in a group. A general approach is to construct an overlay tree and to deliver a multicast packet to multiple receivers over the tree. This paper proposes adaptive overlay trees (AOTs) on wireless ad hoc networks of static nodes for delay- and energy-efficient multicast. A tradeoff function is derived, and an algorithm for AOT construction is developed. Note here that the requirements of delay and energy consumption may vary with different classes of applications. By adjusting parameters in the tradeoff function, different AOTs can be adaptively chosen for different classes of applications. An AOT is constructed in O(ke) time where e is the number of wireless links in a network and k is the number of member nodes in a multicast group. The simulation study shows that AOT adaptively provides tradeoffs between the fastest multicast (which is the choice if delay is the most important factor) and the most energy efficient multicast (which is used when energy consumption is the primary concern). In other words, one of AOTs can be appropriately chosen in accordance with the operation requirement.

• Journal of the Korea Concrete Institute
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• v.26 no.1
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• pp.71-78
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• 2014

The long term integrity of concrete cask is very important for spent nuclear fuel dry storage system. However, there are serious concerns about early deterioration of concrete cask from creaking and corrosion of reinforcing steel by chloride ion because the cask is usually located in seaside, expecially by combined deterioration such as chloride ion and heat, carbonation. This study is to investigate the relation between temperature and chloride ion diffusion of concrete. Immersion tests using 3.5% NaCl solution that were controlled in four level of temperature, i.e. 20, 40, 65, and $90^{\circ}C$, were conducted for four months. The chloride ion diffusion coefficient of concrete was predicted based on the results of profiles of Cl- ion concentration with the depth direction of concrete specimens using the method of potentiometric titration by $AgNO_3$. Test results indicate that the diffusion coefficient of chloride ion increases remarkably with increasing temperature, and there was a linear relation between the natural logarithm values of the diffusion coefficients and the reciprocal of the temperature from the Arrhenius plots. Activation energy of concrete in this study was about 46.6 (W/C = 40%), 41.7 (W/C = 50%), 30.7 (W/C = 60%) kJ/mol under a temperature of up to $90^{\circ}C$, and concrete with lower water-cement ratio has a tendency towards having higher temperature dependency.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.424-431
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• 2016

LID facilities like bio-retention cells is applied to manage stormwater. LID concept becomes an important part in stormwater management, and the clear understanding of hydrologic performance and hydrologic impact on the corresponding catchment has been needed. In this study, the application of flow duration curves as design strategy is investigated. Bio-retention cells like many LID facilities are installed to reproduce natural hydrologic processes. In this study, the attempt to determine the size of a bio-retention cell is carried out to satisfy the flow duration criteria. From the results, it is shown that "5 mm * the area of a target catchment" which is the current facility design capacity is valid for the drainage area with 20-30% impervious rate. In the 100% impervious catchment where LID facilities are typically installed, the design capacity to intercept stormwater of approximately 47 mm depth is required to reproduce natural flow duration curves. This means that about 11% of the target catchment area should be allocated as a bio-retention cell. However, the criteria of the design capacity and facility surface area should be set at the possible implementation conditions in reality, and site-specific hydrologic characteristics of a target catchment should be considered.