PURPOSES : The effect of yellow carpet visibility enhancement was verified and its impact on traffic safety for effective introduction of traffic safety facilities was studied. METHODS : There is currently no scientific evidence demonstrating that yellow carpets improve pedestrian awareness. In this study, the effect of increasing visibility caused by the installation of yellow carpet was verified, and the effect of improving the level of traffic safety was examined through an objective analysis. A drone was used to collect and analyze video data to compare the driving speeds of vehicles passing near yellow carpets at six different sites and diagnose the effects of speed reduction. RESULTS : The results showed that the visibility improvement values before and after the installation of the yellow carpet differed from place to place, but a visibility improvement effect existed in certain cases. In terms of the adequacy of the installation site, the yellow carpet had no deceleration effect on vehicles driving on signalized local streets and collector highways. It was found that there was a speed reduction effect on unsignalized local streets. CONCLUSIONS : To enhance traffic safety promotion, yellow carpets should be placed on unsignalized local streets. It is important to place the yellow carpet in the right place in a proper manner.

The waste secondary battery contains a significant amount of valuable metals, making its recycling highly desirable. However, conventional chemical methods for recycling are environmentally unfriendly and cost-ineffective. Rather than the chemical method, this paper deals with a mechanical method for recovering electrode materials from waste secondary batteries by blowing pressurized air onto the interface area between the electrode and the separator. Especially, in this study, the effective blowing angle were searched by simulating the separation of the electrode material from the separator through 1-way fluid structure interaction analysis based on the Cohesive Zone Modeling technique.

This study was conducted to identify the optimal root zone temperature for paprika cultivation, with an aim to increase the heating and cooling energy efficiency and prepare for extreme weather conditions. The greenhouse air temperature was maintained at 20oC and 25oC during the daytime (12 hours) and at 18oC during the nighttime (12 hours). The plant height did not show any significant differences between the treatment with air temperature and root zone temperature. The root length was highest under an air temperature of 25oC with root zone temperatures of 25oC and 30oC, and it was the lowest at 15oC. The leaf number was the highest when the root zone temperature was adjusted to 25oC and 30oC across all air temperatures. The leaf area increased with higher root zone temperatures, but considering the compactness of the seedlings, a root zone temperature of 25oC was found to be the most effective. The fresh and dry weight of the shoot increased with higher root zone temperatures at an air temperature of 25oC, while the fresh and dry weight of the roots tended to be higher when the root zone temperature was adjusted to 25oC and 30oC across all air temperatures. The compactness was most effective when the root zone temperature was adjusted to 20oC and 25oCC across all air temperatures. Based on the above results, adjusting the root zone temperature to 25oC at an air temperature of 25oC was found to be effective for the early growth of Paprika. The results of this study suggest that not only can growth be promoted through the regulation of root zone temperature, but it also contribute to the establishment of root zone temperature control technology, which can prevent an excessive drop and rise in the root zone temperature.

본 연구는 무안만 조간대의 대형저서생물 군집구조와 퇴적물의 유기물 분포특성과의 관계를 알아보기 위해서 수행되었다. 2019년 8월에 21개 정점에서 퇴적층을 채취하여 입도 및 유기 물 함량(강열감량과 총유기탄소함량)을 분석하였다. 또한 대형저서동물을 분류하고 분포특성을 조사하였다. 조간대 퇴적층의 입도는 무안만 북측 내만이 비교적 조립하였고, 만 입구 주변 은 주로 실트질의 특성을 보였다. 유기물 함량(강열감량과 총유기탄소함량)은 목포 지역 근처 에 위치한 정점 10에서 가장 높았으며, 만의 북측에 위치한 정점 20이 가장 낮았다. 출현한 대형저서동물 중 10% 이상의 점유율을 보인 종은 기수우렁이류(Assiminea sp.), 종밋(Musculista senhousia), 비틀이고둥(Cerithideopsilla cingulata)이었고, 고리버들갯지렁이(Heteromastus filiformis) 4종이었다. 정점 10에서 전체 정점과 비교하여 최대 종수와 밀도를 보였다. 출현종을 토대로 집괴분석과 다차원척도법을 실시한 결과 무안만 조간대는 총 4그룹으로 구분되었다. 상관분석 결과 총유기탄소함량과 생물밀도는 유의한 상관관계(p<0.05)를 보였다. 본 연구결과 에 의해 무안만 조간대에 있어서 대형저서동물 분포는 입도 및 유기물 함량에 따라 다양하게 나타나는 것을 확인할 수 있었다.

The Derived Concentration Guideline Level (DCGL) is required to release the facility from the nuclear safety act at the stage of site restoration of the decommissioning nuclear power plant. In order to evaluate DCGL, there are various requirements, and among them, the selection of input parameters based on the application scenario is the main task. Especially, it is important to select input parameters that reflect site characteristics, and at this time, a single deterministic value or a probabilistic distribution can be applied. If it is inappropriate to apply a particular single value, it may be reasonable to apply various distributions, and the RESRAD code provides for evaluation using probabilistic methods. Therefore, this study aims to analyze the difference between the application of the deterministic method and the application of the probabilistic method to the area and thickness of the contaminated zone among the site characteristics data. This study analyzed the thickness and area of the contaminated zone, and in the case of thickness, the deterministic method was applied by changing the thickness at regular intervals from the minimum depth considered by MARSSIM to the thickness of the unsaturated zone identified in previous research data. In addition, a probabilistic analysis was performed by applying a distribution to the thickness of contaminated zone. Second, for the area of the contaminated zone, the dose was evaluated for each area in consideration of the areas to be considered when deriving Area Factor (AF), and the resulting change in DCGL was observed. As a result, the DCGL tends to decrease as the thickness increases, and it seems to be saturated when the thickness exceeds a certain thickness. Therefore, It was confirmed that the level of saturated values is similar to that of entering a probabilistic distribution, and in the case of a parameter that is reasonable to enter as a distribution rather than as a single value, it is sufficiently conservative to perform a probabilistic evaluation. In the case of area change, the DCGL evaluation result showed that the DCGL increased as the scale decreased. The magnitude of the change varies depending on the characteristics of each radionuclide, and in the case of radionuclides where external exposure gamma rays have a major exposure effect, the change is relatively small. It can be seen that the change in DCGL according to the area has the same tendency as the AF applicable to the survey unit for small survey units applied in the final status survey.

Deep disposal facility for High-Level radioactive Waste (HLW) uses a multi-barrier system to prevent the leakage of radionuclide. As a part of the engineered barrier, bentonite is primarily considered as the main buffering material. This is due to the adsorption and swelling properties of the bentonite, which are expected to effectively impede leakage of the radionuclide. In many cases, adsorption is generally regarded as occurring only within the buffer zone. However, several research has been conducted to explore the possibility of bentonite intrusion into the Excavation- Damaged Zone (EDZ) generated during excavation processes, because of the swelling properties of the bentonite. Generally, for host rock near the deep disposal facility such as granite, groundwater flows through the fracture network. Therefore, analysis of the characteristics of the fracture network is essential for predicting the behavior of radionuclide in groundwater. Accordingly, the bentonite intrusion into the fracture network is critical for safety assessment of the deep disposal facility. To analyze this, hydro-geochemical model was established utilizing COMSOL Multiphysics and PHREEQC, observing changes of the behavior of U (VI) along fracture network due to the swelling of bentonite. Modeling was conducted with progressively changing intrusion depth of the bentonite. According to the results, the behavior of U (VI) exhibited significant changes depending on the connectivity of the fractures. Based on the distribution characteristics of the fracture network, heterogeneous groundwater flow was observed. U (VI) was transported through the preferential pathway, which indicates high connectivity, due to the rapid groundwater flow. Notably, when changing the intrusion depth of bentonite, significant differences in behavior of U (VI) were observed in the 0-20 cm case. In contrast, as the intrusion depth increased, it was observed that differences became less evident. These results indicate that changes in the properties of fracture network in EDZ due to the swelling of bentonite significantly influence the behavior of U (VI).

Raman characteristics of various minerals constituting natural rocks collected from uranium deposits in Okcheon metamorphic zone in Korea are presented. Micro-Raman spectra were measured using a confocal Raman microscope (Renishaw in Via Basis). The focal length of the spectrometer was 250 mm, and a 1800 lines/mm grating was installed. The outlet of the spectrometer was equipped with a CCD (1,024256 pixel) operating at -70°C. Three objective lenses were installed, and each magnification was 10, 50, and 100 times. The diameter of the laser beam passing through the objective lens and incident on the sample surface was approximately 2 m. The laser beam power at 532 nm was 1.6 mW on the sample surface. Raman signal scattered backward from the sample surface was transmitted to the spectrometer through the same objective lens. To accurately determine the Raman peak position of the sample, a Raman peak at 520.5 cm-1 measured on a silicon wafer was used as a reference position. Since quartz, calcite, and muscovite minerals are widely distributed throughout the rock, it is easy to observe with an optical microscope, so there is no difficulty in measuring the Raman spectrum. However, it is difficult to identify the uraninite scattered in micrometer sizes only with a Raman microscope. In this case, the location of uraninite was first confirmed using SEM-EDS, and then the sample was transferred to the Raman microscope to measure the Raman spectrum. In particular, a qualitative analysis of the oxidation and lattice conditions of natural uraninite was attempted by comparing the Raman properties of a micrometer-sized natural uraninite and a laboratory-synthesized UO2 pellet. Significantly different T2g/2LO Raman intensity ratio was observed in the two samples, which indicates that there are defects in the lattice structure of natural uraninite. In addition, no uranyl mineral phases were observed due to the deterioration of natural uraninite. This result suggests that the uranium deposit is maintained in a reduced state. Rutile is also scattered in micrometer-sizes, similar to uraninite. The Raman spectrum of rutile is similar in shape to that of uraninite, making them confused. The Raman spectral differences between these two minerals were compared in detail.

Long-term climate and surface environment changes can influence the geological subsurface environment evolution. In this context, a fluid flow pathway developing and connection possibility can be increased between the near-surface zone and deep depth underground. Thus, it is necessary to identify and prepare for the overall fluid flow at the entire geological system to minimize uncertainty on the spent nuclear fuel (SNF) disposal safety. The fluid flow outside the subsurface environment is initially penetrated through the surface and then the unsaturated area. Thus, the previously proved reports, POSIVA in Finland, suggested that sequential research about the fluid infiltration experiment (INEX) and the investigation is necessary. Characterizing the unsaturated zone can help predict changes and ensure the safety of SNFs according to geological long-term evolution. For example, the INEX test was conducted at the upper part of ONKALO, about 50 to 100 m depth, to understand the geochemical evolution of the groundwater through the unsaturated zone, to evaluate the main flow of groundwater that can approach the SNF disposal reservoir, and to estimate the decreasing progress of the buffering capacity along the pathway through the deep geological disposal. In the present study, a preliminary test was performed in the UNsaturated-zone In-situ Test (UNIT) facility near the KAERI underground research tunnel to design and establish a methodology for infiltration experiments consistent with the regional characteristics. The results represented the methodological application is possible for characterizing unsaturated-zone to perform infiltration experiments. The scale of the experiment will be expanded sequentially, and continuous research will be conducted for the next application.

The microstructure and mechanical properties of the heat-affected zone welded using the GTAW process on SDSS material used in offshore structures were analyzed. The chemical composition of the specimen material was analyzed using XRF. The microstructure of the heat-affected zone where the plate was welded was examined by SEM, and the ferrite volume fraction was assessed using the point count method of ASTM E562. A lot of ferrite was formed in the overheated weldment region, and In the weld cap where the cooling rate was fast, ferrite was not converted back to austenite and the microstructure was not uniform. From the ferrite phase fraction, it was shown that it can be applied to the pitting resistance equivalent numbers through changes in mechanical properties according to welding conditions.

This study used optical and scanning electron microscopy to analyze the surface oxidation phenomenon that accompanies a γ'-precipitate free zone in a directional solidified CM247LC high temperature creep specimen. Surface oxidation occurs on nickel-based superalloy gas turbine blades due to high temperature during use. Among the superalloy components, Al and Cr are greatly affected by diffusion and movement, and Al is a major component of the surface oxidation products. This out-diffusion of Al was accompanied by γ' (Ni3Al) deficiency in the matrix, and formed a γ'-precipitate free zone at the boundary of the surface oxide layer. Among the components of CM247LC, Cr and Al related to surface oxidation consist of 8 % and 5.6 %, respectively. When Al, the main component of the γ' precipitation phase, diffused out to the surface, a high content of Cr was observed in these PFZs. This is because the PFZ is made of a high Cr γ phase. Surface oxidation of DS CM247LC was observed in high temperature creep specimens, and γ'-rafting occurred due to stress applied to the creep specimens. However, the stress states applied to the grip and gauge length of the creep specimen were different, and accordingly, different γ'-rafting patterns were observed. Such surface oxidation and PFZ and γ'-rafting are shown to affect CM247LC creep lifetime. Mapping the microstructure and composition of major components such as Al and Cr and their role in surface oxidation, revealed in this study, will be utilized in the development of alloys to improve creep life.

This study introduces a newly discovered brittle star, Amphiophiura megapoma, from the mesophotic zone in the East Sea, Korea. It is the second species belonging to the genus Amphiophiura (which includes 57 species) to be recorded in Korean waters after A. sculpta. The specimen was discovered during a September 2022 survey, by SCUBA diving in the upper mesophotic zone of the East Sea, Korea. This study presents the morphological characteristics of A. megapoma, highlighting its differences from the related species within a comprehensive taxonomic description. It provides highresolution images of A. megapoma and a taxonomic key for Amphiophiura species in Korea.

PURPOSES : The primary purpose of this study is to develop a framework for predicting the demand and distribution of pedestrians when an open space zone is built at the top through the undergroundization of the Gyeongin Expressway. METHODS : After analyzing the current status through a survey on the number of people, students, surrounding traffic volume, and future socioeconomic indicators, the rate of change in the floating population and the rate of increase and decrease in the traffic volume of pedestrians were calculated to evaluate the effect. In addition, microscopic analysis results were derived by setting a pedestrian analysis zone (PAZ). A walking environment index (WEI) was developed that can quantitatively evaluate the degree of walking activation by indicating walking-related surrounding environmental factors. Based on this, a walking demand prediction model was developed. In addition, the results were validated by calculating the walking volume through a micro-simulation in/around the open space zone. RESULTS : The number of crosswalks and schools, transit development indicators, and pedestrian volume increased as the WEI value increased. However, the log form of the distance was observed to be a factor that reduced walking. CONCLUSIONS : This study attempted to reliably predict the demand for walking on the Gyeongin Expressway by calculating the amount of induced walking and the amount of passing walking. The pedestrian demand can be boosted by improving walking environments.

본 연구에서는 대학생이 직업을 어떻게 선택하는지 밝히기 위하여 진로대안영역과 직업포부를 확인한 후, 자아개념과의 관계를 살펴보았다. 선정된 직업으로 구성된 질문지를 대학생에게 배부하여 총 422명의 사례가 최종 분석에 사용되었다. 수집된 자료를 바탕으로 엑셀 2019와 SPSS 22.0을 사용하여 기술 통계 치, 교차분석, 상관분석을 실시하였다. 연구 결과, 첫째, 중성적이고, 지위에 대한 인식이 높게 나타났다. 둘째, 진로대안영역의 성역할 유형 범위는 3.27점~5.01점, 지위수준은 3.67점~5.29점으로 나타났다. 셋 째, 직업포부는 422명 중 203명(48.1%)이 진로대안영역안에 위치하는 것으로 확인되었다. 넷째, 진로대 안영역의 성역할하한선과 성공욕구는 낮은 부적 관계, 지위상한선과 학업 성적, 주변의 기대, 성공욕구는 낮은 정적 관계로 나타났다. 그리고 직업포부는 지위수준과 주변의 기대, 성공욕구는 낮은 정적 관계로 나 타났다. 위 결과를 바탕으로 제언과 시사점을 논의하였다.

A strain of Amphidinium species was established from samples collected from the intertidal zone of a sandy beach of Jeju Island, Korea. Its cells were 13.0-15.0 μm in length and 10.0-13.0 μm in width. Its cell shape was round or oval and dorsoventrally flat. A pyrenoid was located in the center of the cell and a nucleus was posteriorly located. Its epicone was small and left-deflecting. Its cingulum had V-shape on the ventral side, forming a ventral ridge and extending to the sulcus. Polygonal amphiesmal vesicles and ring-shaped body scales not described previous were observed on the surface of the cell. Its morphological features were consistent with those of previously described Amphidinium fijiense. Phylogeny based on ITS region and LSU rDNA sequences revealed that this Amphidinium isolate was clearly clustered with other A. fijiense strains, but separated from other Amphidinium species. These results indicate that this Amphidinium isolate is A. fijiense. This study reports its presence for the first time in the intertidal zone of a sandy beach of Jeju Island, Korea.