• Current Photovoltaic Research
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• v.10 no.1
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• pp.16-22
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• 2022

The long-term stability of PSCs against visual and UV light, moisture, electrical bias and high temperature is an important issue for commercialization. In particular, since the operation temperature of solar cell can rise above 85℃, a study on thermal stability is required. In this study, the cause of thermal-induced degradation of PSCs was investigated using the SCAPS-1D simulation tool. First, PSCs of TiO₂/CH₃NH₃PbI₃/Spiro-OMeTAD/Au structure were exposed to a constant temperature of 85℃ to observe changes in conversion efficiency and quantum efficiency. Because the EQE reduction above 500 nm was remarkable, we simulated PSCs performance as a function of lifetime, doping density of perovskite and spiro-OMeTAD. Consequently, the main cause of thermal-induced degradation is considered to be the change in the perovskite doping concentration and lifetime due to ion migration of perovskite.

• Science of Emotion and Sensibility
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• v.26 no.1
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• pp.115-132
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• 2023

Previous studies on emotion have repeatedly suggested that alexithymia is an important predictor of depression. Therefore, this study examined whether the relationship between these two variables can be moderated by personality factors, focusing on the Big five personality traits. An online survey of 312 college students, including alexithymia, depression, and Big five personality traits (Extraversion, Agreeableness, Conscientiousness, Emotional Stability, and Openness to Experience) was conducted. As the results, as expected, alexithymia predicted depression, which was in line with the existing research flow. In addition, moderation analysis revealed that agreeableness, emotional stability, and openness to experience moderated the relationship between alexithymia and depression, while extraversion and conscientiousness did not. This study has an important implication in that it discriminated which specific personality traits function as moderators in the process of increasing depression due to alexithymia.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2C
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• pp.59-69
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• 2009

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in crystalline rocks like gneiss, granite, and so on, a prediction model was developed by the use of a decision tree model. The classification standard of the selected prediction model is composed of the slope angle, the coefficient of permeability and the void ratio in the order. The computer program, SHAPP ver. 1.0 for prediction of slope hazards around an important national facilities using GIS technique and the developed model. To prove the developed prediction model and the computer program, the field data surveyed from Jumunjin, Gangneung city were compared with the prediction result in the same site. As the result of comparison, the real occurrence location of slope hazards was similar to the predicted section. Through the continuous study, the accuracy about prediction result of slope hazards will be upgraded and the computer program will be commonly used in practical.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2A
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• pp.223-231
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• 2008

This research presents a new maintenance planning method for deteriorating bridges considering simultaneously the minimization of the maintenance cost and maximization of the bridge performance. Optimal maintenance planning is formulated as a multi-objective optimization problem that treats the maintenance cost as well as the bridge performance such as the condition grade of the bridge deck, girder and pier. To effectively address the multi-objective optimization problem and decision making process for the obtained solution set, we apply a genetic algorithm as a numerical searching technique and adopt a preference-based optimization method. A numerical example for a typical 5-span prestressed concrete girder bridge shows that the maintenance cost and the performance of the bridge can be balanced reasonably without severe trade-offs between each objectives.

• Journal of the Korean Society of Food Culture
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• v.24 no.2
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• pp.137-145
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• 2009

The purpose of this study is to present the scheme that can enhance the value of native local foods by analyzing the case into which storytelling is incorporated in order to revitalize native local foods. Towards this end, the cases of native local foods throughout the country were recommended through professional survey and one region among them was finally selected through the field study. The survey on the native local foods was conducted through qualitative study. The four stages of storytelling: the findings of storytelling, the production of storytelling, the experience of storytelling, and sharing of storytelling were analyzed by stage and the contents of the survey by stage were developed. In the findings of story, the origins and background of the main family's foods and food-related stories were derived. The production of stories deals with how to convey the stories of surveyed native local foods to consumers and it presented the stories about the place and food menu. In the experience of storytelling, the physical environment and non-physical environment, in which people visit native local eating houses and experience native local foods were analyzed. Finally, in the sharing of story, how the tourists who have experienced the native local foods make stories and disseminate and share them was analyzed. The significance of this study is that through the storytelling technique it presented the findings, production, experience and sharing of native local foods in the level that can apply to practical business. Although the research is in the stage of inquiry, this study is meaningful in that it presented the basic methodology that can induce the revitalization of the native local food industry through examining the tradition and significance of native local foods that can be found in all the regions of the country.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.535-540
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• 2006

This paper presented an effective strategy to extract the buildings and to reconstruct 3-D buildings using high-resolution multispectral stereo satellite images. Proposed scheme contained three major steps: building enhancement and segmentation using both BDT (Background Discriminant Transformation) and ISODATA algorithm, conjugate building identification using the object matching with Hausdorff distance and color indexing, and 3-D building reconstruction using photogrammetric techniques. IKONOS multispectral stereo images were used to evaluate the scheme. As a result, the BDT technique was verified as an effective tool for enhancing building areas since BDT suppressed the dominance of background to enhance the building as a non-background. In building recognition, color information itself was not enough to identify the conjugate building pairs since most buildings are composed of similar materials such as concrete. When both Hausdorff distance for edge information and color indexing for color information were combined, most segmented buildings in the stereo images were correctly identified. Finally, 3-D building models were successfully generated using the space intersection by the forward RFM (Rational Function Model).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.519-525
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• 2006

The traditional area-based matching or efficient matching methods using epipolar geometry and height restriction of stereo images, which have a confined search space for image matching, have still some disadvantages such as mismatching and timeconsuming, especially in the dense metropolitan city that very high and similar buildings exist. To solve these problems, a new image matching method through building recognition has been presented. This paper described building recognition in color stereo images using edge and color information as a elementary study of new matching scheme. We introduce the modified Hausdorff distance for using edge information, and the modified color indexing with 3-D RGB histogram for using color information. Color information or edge information alone is not enough to find conjugate building pairs. For edge information only, building recognition rate shows 46.5%, for color information only, 7.1%. However, building recognition rate distinctly increase 78.5% when both information are combined.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.447-456
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• 2009

The design comparison and flexural reliability analysis of continuous span composite plate girder bridges are performed. The girders are designed by the methods of allowable stress design (ASD) and load and resistance factor design (LRFD). For the LRFD design, the design specification under development mainly by KBRC, based on AASHTO-LRFD specification in case of steel structures, is applied with the newly proposed design live load which has been developed by analyzing domestic traffic statistics from highways and local roads. For the ASD based design, the current KHBDC code with DB-24 and DL-24 live loads is used. The longest span length for the 3-span continuous bridges with span arrangement ratio of 4:5:4 is assumed to be from 30 m to 80 m. The amount of steel, performance ratios, and governing design factors for the sections designed by the ASD and LRFD methods are compared. In the reliability analysis for the flexural failure of the sections designed by two methods, the statistical properties on flexural resistance based on the yield strength statistics for over 16,000 domestic structural steel samples are applied.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1C
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• pp.21-31
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• 2009

Based on the proven feasibility of bottom ash and tire shred-soil mixtures as lightweight fill materials, tire shred-bottom ash mixtures were suggested as a new lightweight fill material to replace the conventional construction material (soil) with bottom ash. Therefore, we carried out the field compaction test and performance test of large scale embankment in order to evaluate their suitability for the use of lightweight fill materials. In these tests, we could assess the settlement, earth pressure, stress-strain relation, vibration of large scale embankment which were made with tire shred-bottom ash mixture and the conventional fill material(weathered soil) respectively. The earthpressure and vibration transmission was decreased and the settlement behaviour of the 2 materials (tire shred mixture and weathered soil) was measured similarly under static/cyclic loading condition.

• International Area Studies Review
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• v.15 no.1
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• pp.525-547
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• 2011

Currently, about 58 million Korean Japanese reside in Japan. To overcome the discrimination of the Japanese government and society, the previous generation of Korean Japanese had been maintaining a strong ethnic identity in Japan. But some of Korean Japanese adolescents were naturalized by the Japanese government's assimilation policy. As a result, Korean nationality disclaimer has been increasing. In this context, this study examines what is the determining factors of ethnic identity of Korean Japanese youth, and explores the effect of ethnic identity. The main results of this study are as follows. First, age, name, nationality, school, parental influence, and Korean language skills were confirmed as the determining factors of ethnic identity. Second, Strong ethnic identity of adolescents prevents from naturalization, increases lots of interests about Korea, and makes them positive participation in the Korean network.