• Journal of the Korean Solar Energy Society
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• v.40 no.5
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• pp.1-12
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• 2020

To assess the performance and characteristics of colored building-integrated photovoltaic (BIPV) modules, a comparative assessment of empirical performance was conducted on colored BIPV modules (gray, blue, and orange) and general BIPV module. These modules were installed on the south-facing slope (30°) for comparative assessment through a field test. Monitoring data were collected every 10 min from December 20, 2019 to January 21, 2020 and used to performance and characteristics analysis. Performance ratio and module efficiency were utilized during performance indexing for comparative assessment. For general BIPV modules, the operational efficiency was analyzed at 16.63%, whereas for colored BIPV modules, 13.70% (gray), 15.12 % (blue), and 14.49% (orange) were analyzed. It was discovered that the efficiency reduction caused by transmission losses owing to the application of colored cover glasses were 17.74% (gray), 9.05% (blue), and 9.86 % (orange), under field testing conditions. These values turned on an additional 7% reduction in efficiency for gray BIPV modules, compared to the degradation resulting from transmission drop (gray: 10.87%, blue: 8.99%, and orange: 9.02%) calculated using the efficiency of each module in standard test conditions (STC). Performance ratio analysis resulted in the following values: 0.92 for general BIPV modules, and 0.85 (gray), 0.91 (blue), and 0.91 (orange) for colored BIPV modules. As demonstrated by the above results, modules with a colored cover glass may differ in their operational performance depending on their color, unlike general modules. Therefore, in addition to the performance evaluation under STC, additional factors of degradation require consideration through field test.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.77-82
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• 2019

The purpose of this study is to analyze the relationship between the controlling shareholding ratio and the business diversification of savings banks The difference in this study is the analysis of the relationship between the controlling shareholding ratio of the savings bank and the business diversification using panel data. In this study, the semi-annual financial statements for the period 2014-2018 were used on the basis of a sample of 79 saving banks. The research model is analyzed using random effects generalized linear square (GLS) model considering the autocorrelation problem. As a result of the empirical analysis, it is estimated that the relationship between the controlling shareholding ratio of the savings bank and the business diversification is significant (+). This is the result of supporting the hedging hypothesis.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.82-89
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• 2021

The objective of this study is to propose a new Glide Path that dynamically adjusts the risky asset inclusion ratio of the Target Date Fund by simultaneously considering the market's forecast volatility as well as the time of investor retirement, and to compare the investment performance with the traditional Target Date Fund. Forecasts of market volatility utilize historical volatility, time series model GARCH volatility, and the volatility index VKOSPI. The investment performance of the new dynamic Glide Path, which considers stock market volatility has been shown to be excellent during the analysis period from 2003 to 2020. In all three volatility prediction models, Sharpe Ratio, an investment performance indicator, is improved with higher returns and lower risks than traditional static Glide Path, which considers only retirement date. The empirical results of this study present the potential for the utilization of the suggested Glide Path in the Target Date Fund management industry as well as retirees.

• Steel and Composite Structures
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• v.38 no.2
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• pp.121-139
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• 2021

Ultra-high strength concrete (UHSC) encased steel columns are receiving growing interest in high-rise buildings owing to their economic and architectural advantages. However, UHSC encased steel columns are not covered by the modern fire safety design code. A total of 14 fire tests are conducted on UHSC (120 MPa) encased steel columns under constant axial loads and exposed to ISO-834 standard fire. The effect of load ratio, slenderness, stirrup spacing, cross-section size and concrete cover to core steel on the fire resistance and failure mode of the specimens are investigated. The applicability of the tabulated method in EC4 (EN 1994-1-2-2005) and regression formula in Chinese code (DBJ/T 15-81-2011) to fire resistance of UHSC encased steel columns are checked. Generally, the test results reveal that the vertical displacement-heating time curves can be divided into two phases, i.e. thermal expansion and shortening to failure. It is found that the fire resistance of column specimens increases with the increase of the cross-section size and concrete cover to core steel, but decreases with the increase of the load ratio and slenderness. The EC4 method overestimates the fire resistance up to 186% (220 min), while the Chinese code underestimates it down to 49%. The Chinese code has a better agreement than EC4 with the test results since the former considers the effect of the load ratio, slenderness, cross section size directly in its empirical formula. To estimate the fire resistance precisely can improve the economy of structural fire design of ultra-high strength concrete encased steel columns.

• Structural Engineering and Mechanics
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• v.85 no.5
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• pp.679-691
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• 2023

Many codes allow designers to use the bending moment diagram computed by elastic analysis and modify it by a certain amount of moment redistribution (MR) to account for plastic behaviour of continuous beams. However, several researchers indicated that the MR at the ultimate limit state (𝛽_u) for some beams deviate significantly from the specified values of various codes. This paper examines the applicability of the provisions on 𝛽_u in ACI 318-19 and Eurocode 2 through numerical investigations and comprehensively explores the influencing factors. The results show that some parameters not considered in those codes influence 𝛽_u to a certain extent, where the ratio of tensile reinforcement ratio at intermediate support to tensile reinforcement ratio at midspan (𝜌_s1/𝜌_s2) and load type are crucial parameters to consider. The specific combination of these two parameters may make the codes overestimate or significantly underestimate the 𝛽_u. On the other hand, the yield state of both critical sections is found to have an important influence on the influence degree of each parameter on 𝛽_u. The yield conditions are investigated, and an empirical judgment equation is proposed. In addition, the influence laws of the critical parameters on 𝛽_u have been further proved by theoretical derivation. Finally, due to 𝜀_t is found to have a better linear correlation with 𝛽_u than x_u/d, equations as a function of 𝜀_t for predicting the 𝛽_u of continuous beams under the two loads are proposed, respectively.

• Journal of the Korean Geosynthetics Society
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• v.17 no.3
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• pp.19-32
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• 2018

Gravel Compaction Pile (GCP) method is currently being designed and constructed by empirical method because quantitative design method has not been developed, leading to various types of and frequent destruction such as expansion failure and shear failure and difficulties in establishing clear cause and developing measure to prevent destruction. In addition, despite the difference with domestic construction equipment and material characteristics, the methods applied to the overseas ground is applied to the domestic as it is, leading to remarkable difference between applied values and measured values in variables such as bearing capacity and the settlement amount. The purpose of this study was, therefore, to propose a reasonable and safe design method of GCP method by analyzing the settlement and stress behavior characteristics according to ground strength change under GCP method applied to domestic clay ground. For the purpose, settlement amount of composite ground, stress concentration ratio, and maximum horizontal displacement and expected location of GCP were analyzed using ABAQUS. The results of analysis showed that the settlement and Settlement reduction rate of composite ground decreased by more than 60% under replacement ratio of 30% or more, that the maximum horizontal displacement of GCP occurred at the depth 2.6 times pile diameter, and that the difference in horizontal displacement is slight under replacement ratio of 30%.

• Journal of the Korean Society for Library and Information Science
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• v.22
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• pp.361-396
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• 1992

The purpose of this study is to verify the correlations between the amount of the online searcher's search experience and their search effect. In order to achieve this purpose, the 28 online searchers working at the chosen libraries and information centers have participated in the study as subjects. The subjects have been classified into the two types of cognitive style by Group Embedded Figure Test. As the result of the GEFT, two groups have been identified: the 15 Field Independance ( FI ) searchers and the 13 Field Dependance ( FD ) searchers. The subject's search experience consists of the 3 elements: disciplinary, training, and working experience. In order to get the data of these empirical elements, a questionnaire have been sent to the 28 subjects. An online searching request form prepared by a practical user was sent to all subjects, who conducted searches of the oversea databases through Dialog to retrieve what was requested. The resultant outcomes were collected and sent back to the user to evaluate relevance and pertinence of the search effect by the individual. In this study, the search effect has been divide into relevance and pertinence. The relevance has been then subdivided into the 3 elements : the number of the relevant documents, recall ratio, and the cost per a relevant document. The relevance has been subdivided into the 3 elements: the number of the pertinent documents, utility ratio, and the cost per a pertinent document. The correlations between the 3 elements of the subject's experience and the 6 elements of the search effect has been analysed in the FI and in the FD searchers separately. At the standard of the 0.01 significance level, findings and conclusions made in the study are summarised as follows : 1. There are strong correlations between the amount of training and the recall ratio, the number of the pertinent documents, and the utility ratio on the part of FI searchers. 2. There are strong correlations between the amount of working experience and the number of the relevant documents, the recall ratio on the part of FD searchers. However, there is also a significant converse correlation between the amount of working experience and the search cost per a pertinent document on the part of FD searchers. 3. The amount of working experience has stronger correlations with the number of the pertinent documents and the utility ratio on the part of FD searchers than the amount of training. 4. There is a strong correlation between the amount of training and the pertinence on both part of FI and FD searchers.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.277-282
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• 2019

This study analyzed the determinants of the financial Soundness of savings banks. In particular, empirical analysis was carried out on how the loan deposit ratio correlates with financial soundness after restructuring. As the restructuring of savings banks was finalized in 2014, asset management changed and it is time to analyze the financial characteristics of savings banks. In summary, the relationship between the savings bank lending rate and the NPL ratio is estimated to have a negative value at the 1% significance level. In other words, the higher the mortgage rate, the lower the substandard and below ratio. It can be said that it is not easy for a savings bank to build an aggressive loan portfolio. In other words, the more difficult it is to finance loans through savings deposits, the more likely the risk aversion tends to be. The higher the corporate loan ratio, average interest expense, and economic growth rate, the higher the risk index. The larger the asset size and the higher the loan growth rate, the lower the risk index. Increasing the mortgage rate may reduce risk-seeking behavior, but it does not mean that it is unconditionally positive for savings banks. Therefore, the loan deposit rate regulation should reduce the incentives for excessive asset expansion and manage preemptive soundness through lending portfolio management.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.1-7
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• 2021

The purpose of this study was to analyze the effect of household loan share on bank management soundness. The results of the empirical analysis are summarized as follows. First, as a result of estimating coefficient of the mortgage loan ratio shows a significant negative relationship with the BIS equity capital ratio of banks. In addition, it was found that the mortgage loan ratio had a significant positive (+) effect on Eunhae's BIS and equity capital ratio after the financial crisis. Second, as a result of the estimation coefficient of the mortgage ratio showed a significant positive (+) relationship with the NPL of the bank and below. In addition, it is estimated that the bank's secured loan ratio changed significantly before and after the financial crisis in the effect of banks' NPL and substandard-and-below loans. It is expected to make implication to financial policy and banking regulation and supervision. We believe that more efforts should be made to increase the soundness of household loans in preparation for risk factors that may arise from exogenous factors such as changes in the international financial environment and falling property prices.

• Korean Institute of Interior Design Journal
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• v.27 no.2
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• pp.55-67
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• 2018

There is a growing interest on and expansion of rights of people with disabilities. Among them, people with visual impairment show high adaptation to environments in comparison to people with other types of disabilities, thus a large percentage of them live in their own houses rather than residing in a care facility. According to the housing status of people with visual impairment, the ratio of their residence in rural areas is high. In rural areas people who have disabilities often live in poor residential environments, requiring much improvement. However, such improvement is too costly for them to pay, and home modification that does not fully consider the user, may cause less efficiency and another dangerous situation to people with disabilities. The purpose of this study is to delineate empirical lessons for direction of customized home modification for people with disabilities through analysis of process of home modification including the execution as a intervention. This study used qualitative method to examine and analyzed the entire customized home modification process. The conclusion of this study is as follows. First, home modification measures should be derived considering the suitability of the target building for the specific condition of residents. Second, discussions with various stakeholders from the early stage during which proper home modification measure is searched are essential for realizing appropriate customized home modification. This study has significance in that it provides the direction for customized home modification for people with disabilities as well as empirical data that could reduce trials and errors in the future.