• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.867-878
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• 2018

As the era of AVs (Automated Vehicles) comes to a close, many researches related to AVs have been conducted. Up until now, research on traffic flow impact of AVs has been the main topic, and research on traffic management for AVs is still in beginning stage. This study analyzed the effect of Dynamic Merge Control (DMC) in manual vehicle (MV) and AV environment at work zone. Dynamic Late Merge (DLM) and DLM with Dynamic Early Merge (DEM) are compared by simulation. Simulation results showed that DLM improves travel time and work zone throughput compared to no merge control case in both MV and AV environment. In the case of additional operation of DEM, the improvement effect was not observed in MV environment, but it was improved in AV environment. As a result, DMC operation in AV environment was as effective as the improvement in transition from MV to AV environment. Therefore congestion reduction at freeway work zone by DMC will be possible in future AV environment, and the improvement of DMC can be suggested.

• Journal of Korean Society of Transportation
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• v.34 no.3
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• pp.234-247
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• 2016

As the necessity of the evaluation of environmentally-friendly traffic operations strategies becomes obvious, the characteristics of fuel consumption models should be comprehended in advance. This study selected three fuel consumption models developed in Korea and another three models widely used in North America, and compared their applicabilities. Specifically, the national institute of environmental research (NIER) drive modes and the VISSIM software were utilized to model various driving patterns, and their fuel consumptions were estimated using the fuel consumption models. Based on the results, all the models showed the similar results in the analysis of the most fuel efficient cruising speed. On the other hand, caution should be taken when using the KR-1 and KR-2 models in microscopic analyses because they are not sensitive to instantaneous power requirements of vehicles.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.183-189
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• 2010

This study assess the effects of reclaimed wastewater irrigation on grain quality-related properties of milled rice. To conduct the effects of wastewater reuse on rice quality, the contents of amylose, protein, and milled head rice recovery were analyzed. The water and the soil quality were monitored, and the grain characteristic was analyzed using a NIRS (Near Infra-Red Spectroscopy). The value of the grain properties of the rice which was cultivated with the reclaimed wastewater didn't show a big difference from other common rice. The significant difference by each processing distinction was shown at the significance level of 5% in the statistical result.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.195-205
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• 2021

The purpose of this study is to validate the Confusion, Hubbub, and Order Scale (CHAOS), developed by Matheny et al. (1995), in South Korea. Data of 189 parents with children under the age of 5 acquired by online survey were used for the analysis. Descriptive statistics, item-total correlation, internal consistency, confirmatory factor analysis, convergent validity were examined. As a result, 13 items were confirmed and the reliability was .881. By validating K-CHAOS, it became possible to consider the effect of physical environment, that are known to affect psychological and social development of individuals, as one of micro-systems in future studies.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.59-68
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• 2007

The comparative study using the lab-scale experiment and the discrete element analysis is attempted to analyze the cross-anisotropic elasticity of granular soils. The lab-scale experiment consists of the small stress-controlled triaxial cyclic tests and the bender element tests. In the discrete element analysis the simulations of lab-scale cyclic tests are conducted in the various directions. Good agreement between the experimental data and the simulation on the elastic properties in the axial and shear directions confirms the usefulness of the discrete element method. The comparative analysis of the difference in the experimental data and the simulation of radial cyclic tests shows that the discrete element method can successfully be used to check the reasonable magnitude of each measurement in the experiments.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.82-82
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• 2000

16세기부터 씌워진 과실봉지는 초기 병해충을 방지할 목적만으로 사용되었지만, 현재는 방균과 방충의 효과와 함께 자연현상의 최적화를 위한 차광성, 발수성, 투기성 및 투습성 등 을 조절하며 과실의 외관과 과중 및 당도에까지 영향을 미치는 바 과실봉지의 기능성 부여 를 위해서는 고도의 기술력이 요구되고 있다 하겠다. 실제 과실봉지를 적용하는 한 예로서 “배”를 들 수 있는데, 그 중 황금배는 흑반병, 각 종 병충해 및 동녹으로 인한 상품가치의 하락으로 현재 수요를 충족시키지 못하고 있는 실 정이다. 과피의 비정상적인 코르크화로 인해 발생하는 동녹은 과피의 물리적 할렬과 생리적 장해에 의해 발생하는 것으로 알려져 있다. 과실이 비대해짐에 따라 과피의 기공(과점)이 할 렬하면서 코르크화가 진행되는데 그 발생정도나 시기는 배의 품종에 따라 다르나 일반적으 로 코르크화는 기상조건, 특히 습도와 밀접한 관련이 있다. 황금배의 재배에 봉지를 적용하면 과피의 코르크화가 억제되는데 봉지 내의 대기 환경 이 외기보다 안정적으로 유지되고 직사광선이나 농약 및 마찰로부터 과실을 보호해 주기에 동녹이 어느 정도 방지될 수 있다. 만일 과실이 외부로부터 받는 자극을 적절히 조절하는 기능성 봉지가 제 역할을 다해줄 수 있다면 동녹을 방지하여 외관을 개선함은 물론, 배의 성장에 적합한 미시대기 조건을 제공함에 따라 보다 높은 당도를 지닌 대과의 재배가 가능 하다고 판단된다. 그러나 기존의 황금배봉지는 동녹의 정도를 완화시킬 뿐 완전히 방지할 수 없었으며, 봉지를 적용한 재배조건에서의 동녹 발생기구를 정확히 이해하지 못했었기에 효과적으로 봉지의 기능을 개선하는 것이 불가능하였다. 과실의 미려도는 과실의 맛과 함께 그 가치를 결정짓는 중요한 물성으로서 우리나라 황 금배 재배환경과 특성에 알맞은 배봉지의 제작이 선결될 때, 배 품질의 향상, 안정된 공급이 가능하게 될 것이며 아울러 농가의 수입증대와 수출 경쟁력 강화가 이루어질 수 있을 것으 로 판단된다. 이러한 측면에서 황금배 재배농가가 당면한 동녹발생의 문제점을 효과적으로 해결하고 아울러 기타 과실의 재배용 봉지의 기능성 부여를 위한 새로운 과실 봉지 처리 기 술의 개발이 절실히 요구되고 있다. 상기한 측면에서 본 연구에서는 과실봉지를 적용했을 때 봉지 내의 미시대기 조건이 봉 지의 특성에 따라 변화되는 양상을 파악하기 위해서 실험실적으로 field 조건을 모사하고 봉 지 내의 온도 및 습도를 측정 분석하였다. 아울러 봉지 종류간에 동녹발생 정도가 상이한 점에 예의 주시하여 다양한 봉지의 적용실험을 통해 최적의 과실봉지 조건을 탐색하였다.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.536-548
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• 2019

In order to quantify the effect of the newly established the Total Water Load Management System in Sapgyo watershed, this study predicted the achievement of the target water quality at each unit watershed and the water quality according to the flow section. The HSPF model, which is the watershed runoff model, was constructed and operated based on 2015, and the water quality was predicted by inputting the loads in final target year(2030). The Load Duration Curve (LDC) was created using the simulated results of base year and target year. As a result of plotting water quality by flow conditions, it was simulated to be close to the BOD target with a difference of 0.1 ~ 0.2 mg/L in all three watersheds during the mid-range flow interval (40 ~ 60%). In case of T-P, although the target water quality was not set, the water quality was improved by Cheonan A 46%, Kokgyo A 29% and Namwon A 25%. The Muhan and Sapgyo river basins meet the target grade of middle-watershed standards. The improvement effect will be positive, as water quality, which achieves the target of Total Load Management System and the target grade of the middle-watershed standards will be expected to flow into the Sapgyo lake.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2B
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• pp.153-160
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• 2006

To recommend ecological flow for major tributaries in Han River basin, the Instream Flow Incremental Methodology (IFIM) have been applied. In particular physical habitat simulation using PHABSIM have been selected for microhabitat variables and QUAL2E model have been used to implement macrohabitat simulation. Habitat Suitability Criteria (HSC) for different life stages in accordance with different hydraulic variables (depth and velocity) have been presented by the field surveying data. We review IFIM procedures and discuss limitations of habitat simulation with specific reference to Han River basin. The results of this research can be used as reference flow for estimation of instream flow in Han River.

• Land and Housing Review
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• v.14 no.4
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• pp.47-62
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• 2023

Using the dynamic panel model, this study investigates rent determinants for small and medium-sized office buildings in Korea's CBD and Gangnam areas, key business districts. The results reveal that rents for small and medium-sized office buildings in CBD and Gangnam areas are influenced by macroeconomic fluctuations and characteristics of buildings and locations, suggesting a market with both spatial consumer and investment goods attributes. There are several investment implications as follows. First, even if the location in the CBD area is advantageous, the practical limitations in renovating aging small and medium-sized office buildings must be taken into account when investing. Second, parking conditions are a key factor influencing rent prices in CBD areas, so evaluating the parking facilities and improvement potential of small and medium-sized office buildings is essential for investors. Finally, due to the high sensitivity of Gangnam's small and medium-sized office market to macroeconomic trends, it's vital to prioritize monetary policy shifts as a key factor in investment decisions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2D
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• pp.105-111
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• 2010

Operating speed is one of key elements in the design and operation of freeway. Few studies have been carried out macroscopically to find characteristics of free-flow speed (FFS) using small sample size and not considering the conditions of traffic volume and the effects of hour periods. As an attempt to find out the characteristics of FFS, this study microscopically analysed both the distributions of freeway FFS and percentile speeds according to traffic volume and daily hour periods using huge sample size. It was found out that speed distributions are changed and showed different behaviors under the conditions of traffic volumes(1-5 veh/30sec) and daily hour periods(0-5, 6-8, 9-11, 12-19, 20-23). V85(85th percentile speed) at morning, night, and midnight period decreases according to increase in traffic volume respectively, whereas V85 at day time does not show considerable differences. So the behaviors of V85 according to hour periods dramatically changed according to the increase in traffic volume.