• International conference on construction engineering and project management
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• 2011.02a
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• pp.561-566
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• 2011

In general, the early stage of urban renewal such as preparing a master plan and processing administrative works including planning permission are conducted by local governments in Korea. The local governments need to review the status of projects that are undergone in other local governments' territories. However, no integrated information system to manage information to this end at the level of nation exists in Korea. If the system would be developed, it may support central government to obtain information on required resources at the national level. In addition, local governments can gain guidance on the process and recognize potential problematic situations from others experience. The system should include functions to collect data on project summary, cost and schedule of projects according to local governments. The expected effects from using the information system are as following. First, information generated from project practice become more credible on account of management at the national level. Because the authorized party such as system administrative agents of governments are responsible for collecting and managing data. Second, the unified information system with no regard to the place where projects progresses reduces the efforts for accumulating reference data for aiding local governments decision making by providing appropriate information timely. Also, enhanced information accessibility for stakeholders make the project process clear. Finally, oversight management is enforced with visualization technology adopted in the system, presenting master plan and mass model including information on usage by floors and progressing information graphically. Ultimately, potential challenges can be anticipated by considering records accumulated from other local governments' projects. This paper presents concept, functionalities, and architecture of information system enabling to manage data from individual projects and aggregate those for oversight management for local and central governments. As a part of systems analysis, general requirements of briefing system for governments and necessary data fields to this end are identified.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.141-151
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• 2012

Infrastructure are the essential element in the country for they are the basic facilities forming the basis of economic activity. In Korea Infrastructure which are subject to the management of government are increasing annually, and subsequently the budget of maintenance costs is expected to rise significantly. For the effective management of the constructed and accumulated infrastructure, the integrated management of the future assets will be needed which includes the determination of the asset status, management subjects, and the location, the maintenance of their performance and state, and the prediction of the cost required to increase their useful lifetime. However, in the domestic cases the road facilities valuation has not been done systematically, and the preparation and research on this is scarce. Thus, the systematic procedure for the road facilities valuation is required. In this paper the following study was conducted to derive the reasonable asset valuation methods. First, the valuation methods was investigated and summarized throughout the domestic and international research literature. Second, to apply the investigated valuation methods to the road facilities the valuation process that reflects domestic conditions and characteristics has been developed. Third, a working Bridge, Highways, and General national ways were applied to the general valuation process, and the results were analyzed. As a final step a schematic diagram of the asset management support by WDRC valuation method was presented.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.665-672
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• 2013

This study was conducted to evaluate the effects of a chelating agent on cucumber growth and changes in soil nutrients availability in polytunnel greenhouse fields. Diethylene triamine penta acetic acid (DTPA) was selected as a chelating agent. Two experiments were carried out as follows: i) For field experiment in the autumn season of 2010, each plot was treated by varying the concentration and the number of times being applied with DTPA; [DTPA (0.5 mM, 1 time/3 months), DTPA (0.06 mM, 1 time/1 week), DTPA (0.13 mM, 1 time/2 weeks), DTPA (0.06 mM, 1 time/1 week)+N]. Conventional practice was also investigated. ii) In the spring and summer seasons of 2011, each plot was treated by varying the concentration (0, 0.06, 0.13, 0.19 mM) of DTPA, chemical fertilizers (NPK), and combination of chemical fertilizers and DTPA 0.06 mM. The fruit yields of cucumber and soil chemical properties had no significant differences between treatments. However, in the spring season of 2011, DTPA 0.06 mM plot added 1 time per 2 weeks increased the yield of cucumber, but caused the reduction of yield in next cultivation season. This result showed that excess use of DTPA can cause the damage of crop growth. The inorgainc contents such as Ca and Mg absorbed by cucumber plant had significant differences between DTPA 0.19 mM (2 times/1 week) and fertilizers plus DTPA treatments [DTPA 0.06 mM (2 times/1 week) + 1/2 NPK, DTPA 0.06 mM (2 times/1 week) + NPK]. The input cost of fertilizers was saved when the concentration and the number of times added with DTPA was 0.06 mM and 1 time a week, respectively. This treatment used 67% less of applied fertilizers cost than the plot of conventional practice did. Thus, this research suggested that the application of DTPA 0.06 mM by 1 time a week can be effective for sustainability of crop production and reduction of fertilizers usage in polytunnel greenhouse.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.689-699
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• 2003

This study was to examine characteristics of treating toluene vapor, which gets to be problematic due to its harmful carcinogenicity and mass generation from various sources, through a biological treatment facility which is environment-friendly and adopts a high-efficient and low-cost clean technology. In order to identify whether Alnus Firma Fruit (AFF) can be used as a media for a bioreactor, its utility and basic operating factors, a study was conducted on pressure drop, supply of nutrient substances and retention time which are operating factors of a biofilter, and eliminating characteristics were compared between AFF and the conventional biological activatedcarbon (BAC) widely used as filter media. In the case of AFF, the initial microbial deposits was 2.3${\times}$10$^{7}$ CFU/g dry AFF, which represents the initial microbial density higher than the case of BAC showing 5.5${\times}$10$^{6}$ CFU/g dry BAC And it took about 2 weeks to acclimate until its eliminating rate got to be increased over 90%. As a result of comparing pressure loss taking place with the lapse of time between BAC and AFF, after 130 days passed at SV 25h$^{-1}$ , BAC showed that its eliminating efficiency had a tendency to drop greatly due to a great pressure loss (0.53\longrightarrow54.7 mm$H_2O$/m) caused by an excess of biomass as accumulated. On the other hand. AFF showed that the pressure drop was 0.53 mm$H_2O$/m, about 2 times as much as the initial pressure loss of 0.4 mm$H_2O$/m, which represents no great change in the pressure loss, and its eliminating efficiency was also shown to be continuously high. Therefore, when AFF was used as a filler for a biological treatment facility, a biological filter enabling improvement of the purifying efficiency to be promoted could be provided, and moreover, the pressure loss was so small that the filler replacement cycle or the back flushing cycle could be extended. So, even in terms of the operating cost, it was identified to be an economical filler When an inorganic material was used as a filler, the biofilters performance acted sensitively on whether nutrient substances were supplied or not. In the case of AFF with low adsorptivity, addition of ethyl-alcohol increased the solubility of toluene, and consequently, biodegradation got to be actively made by microbes, and thus, its eliminating rate could be increased. As the flow velocity and the inflow concentration got to be more increased, its eliminating rate got to be lower, and particularly, an increase in the flow velocity made its eliminating rate drop more greatly than an increase in the concentration.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.235-244
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• 2007

Potentials of AR CDM project in North Korea are assessed and feasible land area for AR CDM project is estimated. According to our estimation, There could be 515,000 hectares of forest lands deforested before 1990 in North Korea and 8,854 hectares at the regional level of Gae-sung City, which are eligible for AR CDM project, based on researches of satellite image analyses conducted from 1980's to 1990's. A baseline scenario assumed 44.73 tones of carbon stored in soil per hectare with no vegetation above ground remained during the project period following the default value of IPCC's Good Practice Guidance for LULUCF considering soil structure, climate and land use of the project area. The scenario also assumes that black rocust (Robinia pseudoacacia) is planted and the CDM project is implemented for 20 years. The costs for producing greenhouse gases CER (certified emission reduction) credits include costs of tree planting and forest management, and costs of project negotiation and transactions for issuing the credits. It is estimated that 376 tones of carbon dioxide per hectare can be accumulated and 503 temporary CER credits per hectare and 265 long-term CER credits per hectare could be produced during the project period. It is estimated to cost US$ 4.04 and US$ 7.67 to provide one unit of temporary credit and long-term credit, respectively. These values can be regarded as the cost of conferring emission commitment of a country or a private entity. However, it is not clear which option is better economically because the replacement periods are different in these two cases.

• The Journal of the Acoustical Society of Korea
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• v.22 no.6
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• pp.457-462
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• 2003

In this paper, we propose a speaker pruning method for real-time processing and improving performance of speaker identification system based on GMM(Gaussian Mixture Model). Conventional speaker identification methods, such as ML (Maximum Likelihood), WMR(weighting Model Rank), and MWMR(Modified WMR) we that frame likelihoods are calculated using the whole frames of each input speech and all of the speaker models and then a speaker having the biggest accumulated likelihood is selected. However, in these methods, calculation cost and processing time become larger as the increase of the number of input frames and speakers. To solve this problem in the proposed method, only a part of speaker models that have higher likelihood are selected using only a part of input frames, and identified speaker is decided from evaluating the selected speaker models. In this method, fm can be applied for improving the identification performance in speaker identification even the number of speakers is changed. In several experiments, the proposed method showed a reduction of 65% on calculation cost and an increase of 2% on identification rate than conventional methods. These results means that the proposed method can be applied effectively for a real-time processing and for improvement of performance in speaker identification.

• Journal of Wetlands Research
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• v.9 no.2
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• pp.1-8
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• 2007

Since 2000, environmental policies and regulations in Korea are rapidly changing to TMDL(Total Maximum Daily Load) and nonpoint source control. This is due to bad water quality in drinking water sources. Although many environmental facilities having high removal efficiency are constructed and applied in nationwide for controling various pollutants from wastewaters, the water quality in rivers is worse and worse because of nonpoint pollution. In fact, TMDL is a new environmental regulation controling total daily loadings from watershed areas. Actually, the nonpoint pollutant is originated from various landuses and its control is based on TMDL regulation. Therefore, this research is performed to determine the size of detention basin to control nonpoint pollutants from resort developing areas. The detention basin is one of best management practices, which is useful for controling pollutants and flooding from the developing areas. However, it should be designed and constructed with cost effective method. Recent 10 years rainfall data are used to determine the size of detention basin. The cost effective size is determined to 7.4mm accumulated rainfall.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.2
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• pp.71-78
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• 2012

The digital tachograph is a device that automatically records speed and distance of a vehicle, together with the driver's activity and vehicle status at an accident. It records vehicle speed, break status, acceleration, engine RPM, longitude and latitude of GPS, accumulated distance, and so on. European Commission regulation made digital tachographs mandatory for all trucks from 2005. Republic of Korea made digital tachographs mandatory for all new business vehicles from 2011 and is widening the range of vehicles that must install digital tachographs year by year. This device is used to analyze driver's daily driving information and car accidents. Under a car accident that makes the device reliability unpredictable, it is very important to store driving information with maximum reliability for its original mission. We designed and implemented a practical digital tachograph. This paper presents a storage scheme that consists of a first storage device with small capacity at a high reliability and a second storage device with large capacity at a low cost in order to reliably records data with a hardware at a low cost. The first storage device records data in a SLC NAND flash memory in a log-structured style. We present a reverse partial scan that overcomes the slow scan time of log-structured storages at the boot stage. The scheme reduced the scan time of the first storage device by 1/50. In addition, our design includes a scheme that fast stores data at a moment of accident by 1/20 of data transfer time of a normal method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.6
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• pp.381-389
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• 2023

One of the crucial components in building information modeling (BIM) is data. To systematically manage these data, various research studies have focused on the creation of object breakdown structures and property sets. Specifically, crucial data for managing programs and payments involves work breakdown structures (WBSs) and cost breakdown structures (CBSs), which are indispensable for mapping BIM objects. Achieving this requires disassembling CBS quantities based on 3D objects and WBS. However, this task is highly tedious owing to the large volume of CBS and divergent coding practices employed by different organizations. Manual processes, such as those based on Excel, become nearly impossible for such extensive tasks. In response to the challenge of computing quantities that are difficult to derive from BIM objects, this study presents methods for disassembling length-based quantities, incorporating significant portions of the bill of quantities (BOQs). The proposed approach recommends suitable CBS by leveraging the accumulated history of WBS-CBS mapping databases. Additionally, it establishes a unified CBS code, facilitating the effective operation of CBS databases.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.357-371
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• 2017

In this study we evaluated the availability of hairy vetch in citrus (Citrus unshiu Marc.) orchards of volcanic ash soils. The responses to increasing seeding rates and various growing conditions such as altitude, accumulated temperature, and soil chemical properties etc, were analyzed by means of the seedling establishment rate, weed occurrence ratio, and shoot biomass yield of hairy vetch. Field experiments were conducted at five citrus orchards by altitude from Sep. 2015 to Apr. 2016 in Jeju Island, Republic of Korea. Hairy vetch used in the study was 'Cheongpyungbora', developed by National Institute of Crop Science. Seeding rates of hairy vetch consisted of 30, 60 and $90kg{\cdot}ha^{-1}$. Results showed that the seedling establishment rates of hairy vetch were quite similar regardless of seeding rates in all fields and weed occurrence ratio at 30, 60 and $90kg{\cdot}ha^{-1}$ of seeding rates were 11.8, 3.8, and 5.1% (dry wt.), respectively. Both 60 and $90kg{\cdot}ha^{-1}$ of seeding rates, the weed occurrences were decreased by 96.2% and 94.9%. The nitrogen production of hairy vetch at 30, 60 and $90kg{\cdot}ha^{-1}$ of seeding rates were 254, 316, and $315kg{\cdot}ha^{-1}$, respectively. Both 60 and $90kg{\cdot}ha^{-1}$ of seeding rates, The nitrogen production were increased by 24%, compared to $30kg{\cdot}ha^{-1}$ of seeding rate. In these results we were considered that the cost-efficient seeding rate of vetch was $60kg{\cdot}ha^{-1}$ in citrus orchards. Also, this study showed that the shoot biomass of hairy vetch and various cultivative factors were related and The nitrogen production of hairy vetch had a little bit of positive correlation (R=0.2714) with accumulated temperature and considerable correlations with some items (EC ($R=0.4520^{**}$) and exchangeable K ($R=0.4078^{**}$)) of soil chemical properties. Therefore, we were considered that hairy vetch can be used as a leguminous cover crop in citrus orchards, the calculation formula (Y=4.4097X + 33.594 (R=0.9547)) can be suggested for nitrogen yield of hairy vetch by using the shoot fresh weight (X).