• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.107-116
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• 2005

The information on travel time in providing the information of traffic to drivers is one of the most important data to control a traffic congestion efficiently. Especially, this information is the major element of route choice of drivers, and based on the premise that it has the high degree of confidence in real situation. This study developed a vehicle arrival time prediction algorithm called as "VAT-DV" for 6 corridors in total 6.1Km of "Nam-san area trffic information system" in order to give an information of congestion to drivers using VMS, ARS, and WEB. The spatial scope of this study is 2.5km~3km sections of each corridor, but there are various situations of traffic flow in a short period because they have signalized intersections in a departure point and an arrival point of each corridor, so they have almost characteristics of interrupted and uninterrupted traffic flow. The algorithm uses the information on a demand volume and a queue length. The demand volume is estimated from density of each points based on the Greenburg model, and the queue length is from the density and speed of each point. In order to settle the variation of the unit time, the result of this algorithm is strategically regulated by importing the AVI(Automatic Vehicle Identification), one of the number plate matching methods. In this study, the AVI travel time information is composed by Hybrid Model in order to use it as the basic parameter to make one travel time in a day using ILD to classify the characteristics of the traffic flow along the queue length. According to the result of this study, in congestion situation, this algorithm has about more than 84% degree of accuracy. Specially, the result of providing the information of "Nam-san area traffic information system" shows that 72.6% of drivers are available.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.447-447
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• 2016

홍수 시 하천을 따라 유하되는 유송잡물(잡목, 생활쓰레기 등)은 구조물에 집적이 이루어지며 이로 인해 물의 흐름을 방해하고 구조물 주변의 지반을 약화시키거나 월류로 인해 심각한 피해를 야기 시킨다. 교량의 경우 유송잡물의 집적은 교각의 항력을 증가시켜 전도파괴를 유발시킬 수 있으며, 교각주변 흐름교란을 통한 하상세굴로 인해 기초부를 파괴시키기도 한다. 또한 통수단면적 증가로 인해 높아진 수위는 제방을 월류시켜 재산 및 인명피해를 유발하기도 한다. 암거의 경우 유송잡물을 포함한 토사로 인해 단면폐색 및 침식으로 암거의 파괴를 발생시키고 이로인해 도로의 단절을 가져오기도 한다. 이러한 유송잡물에 대한 차단대책은 현재 까지 유지관리를 통한 방법만이 최선책으로 제시되고 있다. 본 연구는 국외에서 소개되고 있는 유송잡물 피해저감시설을 대상으로 축소모형실험을 통해 효과를 확인하고 이를 통해 저감시설의 효율에 대해 소개하고자 하는 것이 주목적이다. 유송잡물 저감시설은 교량의 경우 수직분리대 방법, 우회말뚝 방법, 스위퍼를 이용한 방법으로 소개하고 있으며 이들 방법의 특징은 유송잡물 우회를 통해 집적을 저감하는 방식이다. 암거의 경우 수직분리대 방법, 스크린 방법, 우회스크린을 이용하는 방법 등이 있으며 수직분리대는 교량과 마찬가지로 우회방식을 기본방식으로 스크린 방식은 유송잡물의 차단을 원칙으로 하고 있다. 실험의 결과는 교량과 암거의 차단시설 유무에 따른 유송잡물의 집적률을 대상으로 하였다. 차단시설이 없는 경우 교량에서의 집적률은 97.9% ~ 99.2%의 집적률로 나타났다. 수직분리대의 경우 유송잡물 집적률은 49.3%, 우회말뚝은 0.0% ~ 4.2%의 범위로 매우 높은 차단효과를 보이고 있었다. 스위퍼방식의 경우 집적률은 5.3% ~ 20.9%로 나타났다. 이러한 결과로 판단하였을 때 차단시설 설치로 인한 교량에 대한 직접적인 차단효과는 수직분리대 < 스위퍼 < 우회말뚝 순으로 높은 차단효과를 보이는 것으로 나타났다. 그러나 우회말뚝에서의 집적률이 한계치를 넘어선다면 유송잡물로 인해 흐름교란, 수위 및 하상변동, 말뚝의 유실 등으로 인한 피해가 예상된다. 암거대상 유송잡물 차단시설 실험결과는 수직분리대의 경우 type과 투하방법에 따라 차이가 있지만 집적률은 14.7% ~ 64.9%의 범위로 나타났다. 스크린과 우회스크린 방식은 유송잡물의 우회가 아닌 차단이 목적이므로 유송잡물 집적에 의한 수위상승이 우려되는바 수위영향을 검토하였다. 검토결과 스크린 설치로 인한 수위상승이 우회스크린보다 높게 상승하는 것으로 나타났다. 이러한 결과는 스크린의 형태적인 측면에서 2면을 통해 집적되는 특성을 갖는 우회스크린이 통수단면적을 많이 확보하기 때문이다. 따라서 국부적인 수위상승으로 인한 피해를 저감하기 위해서는 설치여건이 허용된다면 통수단면적 확보가 유리한 우회스크린 설치가 유리할 것으로 판단된다.

• Journal of IKEEE
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• v.23 no.2
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• pp.743-746
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• 2019

In this paper we proposed a new ocean radiation automatic monitoring system. The proposed system has the following characteristics: First, using NaI + PVT mixed detectors, the response speed is fast and precision analysis is possible. Second, the application of temperature compensation algorithm to scintillator-type sensors does not require additional cooling devices and enables stable operation in the changing ocean environment. Third, since cooling system is not needed, electricity consumption is low, and electricity can be supplied reliably by utilizing solar energy, which can be installed at the observation deck of ocean environment. Fourth, using GPS and wireless communications, accurate location information and real-time data transmission function for measurement areas enables immediate warning response in the event of nuclear accidents such as those involving neighboring countries. The results tested by the authorized testing agency to assess the performance of the proposed system were measured in the range of $5{\mu}Sv/h$ to 15mSv/h, which is the highest level in the world, and the accuracy was determined to be ${\pm}8.1%$, making normal operation below the international standard ${\pm}15%$. The internal environmental grade (waterproof) was achieved, and the rate of variation was measured within 5% at operating temperature of $-20^{\circ}C$ to $50^{\circ}C$ and stability was verified. Since the measured value change rate was measured within 10% after the vibration test, it was confirmed that there will be no change in the measured value due to vibration in the ocean environment caused by waves.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.217-225
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• 2021

In this study, wave spectrum data were calculated using the water surface elevation data observed at 5Hz intervals from the HeMOSU-2 meteorological tower installed on the west coast of Korea, and wave parameters were estimated using wave spectrum data. For all significant wave height ranges, the peak enhancement parameter (γ_opt) of the JONSWAP spectrum and the scale parameter (α) and shape parameter (β) of the modify BM spectrum were estimated based on the observed spectrum, and the distribution of each parameter was confirmed. As a result of the analysis, the peak enhancement parameter (γ_opt) of the JONSWAP spectrum was calculated to be 1.27, which is very low compared to the previously proposed 3.3. And in the range of all significant wave heights, the distribution of the peak enhancement parameter (γ_opt) was shown as a combined distribution of probability mass function (PMF) and probability density function (PDF). In addition, the scale parameter (α) and shape parameter (β) of the modify BM spectrum were estimated to be [0.245, -1.278], which are lower than the existing [0.300, -1.098], and the result of the linear correlation analysis between the two parameters was β = -3.86α.

• Journal of the Korean earth science society
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• v.43 no.2
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• pp.324-347
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• 2022

Geological information on the Korean Peninsula plays a significant role in science education because it provides a basic knowledge foundation for public use and creates an opportunity to learn about the nature of geology as a historical science. In particular, the Mesozoic Era, when the Korean Peninsula experienced a high degree of tectonic activity, is a pivotal period for understanding the geological history of the Korean Peninsula. This study aimed to analyze whether content regarding the geology of the Mesozoic Era are reliably and consistently presented in the 'Geology of the Korean Peninsula' section of Earth Science II textbooks based on the 2015 revised curriculum. Four textbooks for Earth Science II were analyzed, focusing on the sedimentary strata, tectonic movement, and granites of the Mesozoic Era. The analysis items were terms, periods, and rock distribution areas. The consistency within and among textbooks and of textbooks and scientific knowledge was analyzed for each analysis item. Various inconsistencies were found regarding the geological terms, periods, and rock distribution areas of the Mesozoic Era, and suggestions for its improvement were discussed based on these inconsistencies. It is essential to develop educational materials that are consistent with the latest scientific knowledge through collaboration between the scientific and educational communities.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.435-442
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• 2022

In this study, the density of KS L 5110 was compared with that of gas pycnometer and electronic densimeter for efficient density management of cement, blast furnace slag powder and fly ash. Correlation and usability according to the test method were reviewed, and based on the results of the experiment, the availability of alternative test methods was analyzed. As a result of the density test according to test methods, the density of cement, blast furnace slag powder and fly ash tended to decrease in the order of gas pycnometer, KS L 5110 and electronic densimeter. Because the volume range of the sample to be evaluated is different depending on test methods. The coefficient of determination R² was in the range of 0.71 to 0.93, and the correlation according to test methods showed a relatively good correlation. If correction is applied through correlation, it is analyzed that alternative test methods can be used. As a result of the usability review considering the test procedure, measurement time and coefficient of variation, the gas pycnometer had the simplest test procedure and good reliability. In addition, it is expected that the reproducibility between the testers is relatively high because the skill is not greatly required.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5A
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• pp.433-442
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• 2010

A control of chloride diffusion coefficient is very essential for service life of reinforced concrete (RC) structures exposed to chloride attack so that much studies have been focused on this work. The purpose of this study is to derive the intended diffusion coefficient which satisfies intended service life and propose a technique for optimum concrete mixture through genetic algorithm(GA). For this study, 30 data with mixture proportions and related diffusion coefficients are analyzed. Utilizing 27 data, fitness function for diffusion coefficient is obtained with variables of water to binder ratio(W/B), weight of cement, mineral admixture(slag, flay ash, and silica fume), sand, and coarse aggregate. 3 data are used for verification of the results from GA. Average error from fitness function is observed to 18.7% for 27 data for diffusion coefficient with 16.0% of coefficient of variance. For the verification using 3 data, a range of error for mixture proportions through GA is evaluated to 0.3~9.3% in 3 given diffusion coefficients. Assuming the durability design parameters like intended service life, cover depth, surface chloride content, and replacement ratio of mineral admixture, target diffusion coefficient, where exterior conditions like relative humidity(R.H.) and temperature, is derived and optimum design mixtures for concrete are proposed. In this paper, applicability of GA is attempted for durability mixture design and the proposed technique would be improved with enhancement of comprehensive data set including wider range of diffusion coefficients.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.3
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• pp.115-123
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• 2010

The occurrence and variation of oxygen deficient water mass (ODW) in Namdae stream estuary, Yangyang were studied. Field observations for water properties and sediment environments were conducted at 5 stations of the estuary from April 2008 to November 2008. The coastal sandbar is developed at the estuary mouth, and there is a pool between the estuary mouth and about 2.3 km upstream of the estuary. The pool is relatively deep and narrow compared to riverbed of the estuary. The ODW was observed continuously in the pool from May to October. The ODW extends vertically up to 2 m depth in August, and maximum length of the ODW were about 2.3 km. Mean concentration of ignition loss (IL) and acid volatile sulfide (AVS) of sediment was 7.5~9.0%, $0.282{\sim}1.106\;mg/g{\cdot}dry$ wt, respectively. Ammonium concentration in the bottom layer during formation period of the halocline and the ODW was 4~23 times higher than that of surface layer. ODW was initiated by the introduction of seawater into bottom of the estuary pool to make a strong halocline, and then decomposition of organic matter within sediment accelerated the formation of the ODW.

• Journal of Cadastre & Land InformatiX
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• v.54 no.1
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• pp.33-48
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• 2024

This study aims to establish the scope and statistics of the K-address information industry in Korea, estimating its size and prospects and estimates the economic effects through K-address information industry based on Input-Output analysis. Considering the characteristics and sectoral structure of the K-address information industry, the study delineates the scope and specific sectors, constructing sectoral statistics linked to the KSIC and the Bank of Korea's industrial classification. The study estimates the sectoral industry size, taking into account potential markets. Furthermore, it analyzes the economic impact of each sector within the K-address information industry. To figure out the economic effects, the study conducts Input-Output analysis by setting the K-address information industry as an exogenous sector in the input-output table. The results indicate that the overall size of the K-address information industry is estimated to grow from 406.1 billion KRW in 2021 to 3.65 trillion KRW in 2030. The economic effects of the K-address information industry vary by sector, emphasizing the importance of synergies and integration with related sectors, particularly those with significant inducement effects in high value-added manufacturing and service sectors. Furthermore, the industry's sensitivity to economic fluctuations is evident through the input-output analysis of inter-industry chain effects.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.265-276
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• 2014

This study observes innovation demand in design education according to IT environment in change, and explores reasonable directivity of design education according to fluctuations in media and technologies by presenting academic possibility of interactive design field and its education paradigms for universities. In order to achieve highly added values through interactive design complying with social demand, accompanying researches and academic frames are to be prepared, in particular with independent academic domain frame in universities, this study presents an educational directivity by recognizing important establishments of related curriculum that must be proceeded. This study has made a contribution in addressing the necessity of establishment of individual academic domain for interactive design and also setting up the domain of interactive design. It has been concluded that technological understanding beyond conventional design education, management of complex issues in consideration, and methodology of differentiated education in corresponding to the situation needed as well as typical educations of conventional technologies should be provided for satisfying innovation demand in the domain of interactive design.