• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.285-292
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• 2014

BIM (Building Information Modeling) is a new paradigm that includes construction life-cycle, and BIM has become mandatory regulation according to the Public Procurement Service since 2016, which accelerates its application. BIM is now expand from architectural field to infrastructure industry. Through pilot projects, BIM has been challenged with verification process. This trend has affected to maintenance and operation (M&O) phase of construction life-cycle. Advanced country has already published their research and result with feasibility study and guidelines. In this paper, we conduct the feasibility study to adopt BIM-based infrastructure management system. Bridges and tunnels were selected as application target, and benefit/cost ratio were used. The result shows that BIM-based infrastructure management system is feasible when the level of detail is more than "Medium" in bridge, and "High" in tunnel.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.867-867
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• 2012

기후변화와 변동으로 인해 기온, 강수, 증발산 등의 수문순환 요소들이 과거와는 다르게 빠른 속도로 변하고 있다. 이에 따라 지난 수십 년간 기후변화가 수문학적 극한사상에 미치는 잠재적 영향은 수자원공학 관련 분야에서 관심 대상이 되어왔으며, 많은 선행 연구들은 극한 수문사상의 규모 및 빈도가 증가한다는 결과를 보여 주었다. 우리나라의 경우 최근 10년간(1999~2008년) 1일 100mm 이상 집중호우의 발생빈도는 총 385회로, 70~80년대 222회에 비해 무려 1.7배나 증가했다. 2011년의 경우 7월초부터 8월 중순까지 지속적인 장마와 집중호우로 인해 1285.3mm의 누적강수량이 발생하였으며, 서울 및 수도권 지역에서 100년 빈도 설계강수량을 초과하는 집중호우 발생으로 서울의 도심지역 곳곳이 침수되어 많은 재산피해와 인명피해를 입혔다. A1B 기후변화 시나리오에 따르면 21세기말(2071~2100년)에는 20세기말(1971~2000년)에 비해 약 17%가 증가할 것으로 전망하고 있다. 이처럼 기후변화는 특히 도시수공시설물을 설계하는데 있어 가장 중요한 변수인 극한강우사상을 변화시키기 때문에 도시배수시설물을 계획하고 설계하는 수공기술자들에게 기후변화를 고려하는 일은 자명한 일이다. 또한, 기후변화로 인한 수문과정의 점진적 변화 영향은 도시배수관련 기반시설물의 첨두홍수량과 빈도를 변화시킬 것으로 예상하고 있다. 이에 본 연구에서는 기후변동이 도시배수체계에 미치는 영향을 평가하기 위해 외부기상인자의 변동을 반영할 수 있는 비정상성 빈도해석기법을 이용하여 지속시간 1기간, 3시간, 24시간 빈도별 설계강수량을 산정한 후 도시유출모형인 XP-SWMM 모형을 통해 도시배수체계에 미치는 영향을 평가하였다. 이를 통해 현재의 도시배수체계와 비교함으로써 기후변동이 도시배수체계에 미치는 영향을 정량화하였다.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.791-798
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• 2009

The role of forest and soil carbon under global climate change is getting important as a carbon sink and it is necessary to research on applicable forest models as well as in the field for a study of these dynamics. On this study, historical annual litter dataset as a major input data for the forest soil carbon model, Yasso was established using a dendrochronological reconstruction method, and the soil carbon dynamics of a Pinus densiflora forest in Gwangneung, Korea was simulated using Yasso. The amount of litter (needle, branch, stem and fine root) production, which was estimated using the dendrochronological method, has increased continuously from 1971 to 2006. Furthermore, there was no significant error between estimated and measured values of litter production (needle and branch) in 2006. The average of simulated soil carbon stock up to 30 cm depth was $46.30{\pm}4.28tCha^{-1}$, which accounted for 53% of carbon stock in trees of the forest, and had no significant difference and error with measured soil carbon stock. Under the climate change trend in Korea according to IPCC A1B scenario, it was estimated that the simulated soil carbon stock in the region would increase continuously from 1971 to 2041 and then decreased until 2100. Compared to the result of the scenario that there is no climate change, the soil carbon stock could be decreased up to 7.58% at 2100. It was inferred the dendrochronological reconstruction method and simulation of Yasso model are useful to estimate soil carbon dynamics of the natural P. densiflora forest. Follow-up researches, such as improvement of the dendrochronological method and Yasso model and their application and validation in various environment, are needed to produce more reliable results.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.25-39
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• 2013

In this study, the change of the discharge according to the land cover change which acts as one of dominant factors for the outlook of future discharge was analyzed using SWAT(Soil and Water Assessment Tool) model for Yongdam and Daecheong Dam Watershed in the Geum River Basin. The land cover maps generated by Landsat TM satellite images in the past 1990 and 1995 were used as observed data to simulate the land cover in 2000 by CA-Markov serial technique and after they were compared and verified, the changes of land cover in 2050 and 2100 in the future were simulated. The discharge before and after the change of land cover by using input data of SWAT model was compared and analyzed under the A1B scenario. As a result of analyzing the trend in the elapses of year on the land cover in the Geum River Basin, the forest and rice paddy class area steadily decreased while the urban, bare ground and grassland classes increased. As a result of analyzing the change of discharge considering the future change of the land cover, it appeared that the discharge considering the change of land cover increases by 1.83~2.87% on the whole compared to the discharge not considering the change of land cover.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.35-42
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• 2016

Formamide is a colorless fluid with ammonia odor, and irritable when inhaled. It has $LD_{50}$ value of > 5,577 mg/kg in rats for acute oral toxicity and NOAEL of 113 mg/kg/day for target organ (liver) of whole body toxicity. It is also known as reproductive toxicant (1B) and TWA(Time Weighted Average) for it is 10 ppm. Workplace measurements of work places dealing with formamide showed the ppm of all 25 samples was very lower than WEL. However, the exposure concentration can change, depending on workplace condition such as the intensity of work, operating local ventilation system, and wearing protection equipment (Respirators). Therefore, considering it with the risk of whole body toxicity and reproductive toxicity, exposure quantity of each imaginary scenario was calculated at 5.16, 1.72, and $0.43mg/m^3$. The average value was calculated at 0.02-0.58, 0.02-0.66 at 90 percent of cumulative distribution, 0.02-0.69 at 95 percent of cumulative distribution. Therefore, it was generally evaluated to be safe because all values were below 1. However, caution is required to prevent health hazard because it has hepatotoxicity and reproductive toxicity and risk of a high level momentary exposure, depending on the condition of workplace.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3B
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• pp.91-99
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• 2008

In this paper, we design the function of ULSLE(Upper Layer Shared LAN Emulation) to provide both the efficient LAN service and compatibility with 802.1D bridge in Hybrid two-stage AWG based WDM-PON. The ULSLE layer lies above MAC control layer in order to provide a mean to interface WDM-PON and 802.1D bridge. It also performs LAN emulation based on PON-Tag which is only used to decide both the transmission mode and the destination of frames transmitted from ONUs. That is, the PON-Tag is not used for downstream frames but destination address field in original frame instead. This decreases the processing overhead and complexity caused by PON-Tag at OLT and ONU. The verification of designed ULSLE is performed according to the specific scenarios based on transmission mode and destination using OPNET.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.809-822
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• 2018

A quantitative risk assessment has been introduced to quantitatively evaluate fire risk as a means of performance based fire protection design in the design of railway tunnel disaster prevention facilities. However, there are insufficient studies to examine the effect of various risk factors on the risk. Therefore, in this study, the risk assessment was conducted on the model tunnel in order to examine the effects of the evacuation start time delay and the fire growth curve on the quantitative risk assessment. As a result of the analysis of the scenario, the fatalities occurred mainly when escapes in the same direction as the direction of the fire smoke movement. In addition, after the FED exceeded 0.3, the maximum fatalities occurred within 10 minutes. In the range of relatively low risk, distance between cross passages, evacuation delay time and fire growth curve were found to affect the risk, but they were found to have little effect on the condition that the risk reached the limit. Especially, in this study, it was evaluated that the evacuation delay time reduction, fire intensity and duration reduction effect were not observed when the distance between cross passages was more than 1500 m.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.1
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• pp.10-19
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• 2011

In order to predict the risk of anthracnose on hot pepper in the future, the projected climate data from SRES A1B scenario in South Korea were used with the modified anthracnose model to calculate Infection Risk (IR), which was to estimate the number of fungicide sprays. Based on daily temperature and precipitation, the anthracnose model resulted in an empirical relationship that IR = (Daily temperature - $16^{\circ}C$) ${\times}$ 0.07 + (Daily precipitation ${\times}$ 0.11). For 135 locations in South Korea, the total number of fungicide sprays needed from 2011 to 2100 was 12,150, indicating a complicated change with an overall increase in anthracnose development in all locations until 2100. In particular, radical changes in anthracnose development were predicted at Yeongdeok, Yeongyang, and Uiseong, whereas gradual changes were predicted at Heongsung, Hamyang and Taean. The eastern counties of Gyeongbuk Province, which ar the major plantation area in these days, would be the place with the highest disease pressure in the future. In addition, the years of 2058, 61, 78 and 2096 will be most severe, requiring 8-11 times of fungicide spraying. The GIS maps show that the mountain areas of Jeonbuk and Chungbuk Province would have the least disease pressure of anthracnose in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.3
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• pp.236-247
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• 2011

This study investigates sea level (SL) rise due to global warming in the Northwestern Pacific (NWP) and Seas around the Korean peninsula (KP) using outputs of IPCC AR4 climate models. Particularly, components of the SL rise induced by a local steric effect, which was not considered in most climate models, were computed using model-projected 3-dimensional temperature and salinity data. Analysis of the SL data shows that the ratio of the SL rise in the NWP and KP was about two times higher than that in global mean and particularly the ratio in the Kuroshio extension region was the highest. The SL rises over 100 years estimated from MPI_ECHAM5 and GFDL_CM2.1 model by A1B scenario considering the thermosteric effect were 24 cm and 28 cm for the NWP and 27 cm and 31 cm for the Seas around the KP, respectively. Statistical analysis reveals that these SL rises are caused by the weakening of the Siberian High in winter as well as variations of pressure system in the NWP and by the resultant change of water temperature. It also found that the highest SL rise in the Kuroshio extension region of the NWP was connected with the large increase of water temperature in this area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1B
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• pp.38-47
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• 2008

The system test was accomplished in delivery time for a suitable of various requirements at the software market. Especially, critical faults must be detected and removed for a close main functions and users against target system. In generally, proposed test methods are executed with a calendar time, not a competitive and effectiveness method as selective software testing. These methods are inapplicable to short term test or early system development stage. Moreover, it's accompanied by heavy cost. Overcoming of these problems, must attempted to new software test method role of core function in the system test. Selective software testing method is decided to mixing with the three-information such as a frequency, complexity of use scenario and fault impact. Using this information, searching a fatal error and usefully system test for an executed test scenario. In this paper, we have proposed new test method and verified testing results for the detection of critical faults or search a fatal errors with a system main function.