• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.4
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• pp.391-397
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• 2016

Vibration disturbances induced by the reaction wheels can severely degrade the performance of high precision payloads on board satellites with high pointing stability requirements. The unwanted disturbances produced by the reaction wheels are composed of fundamental harmonic disturbances due to the flywheel imbalance and sub/higher harmonic disturbances due to bearing irregularities, motor imperfections and so on. Because the wheel speed is constantly changed during the operation of a reaction wheel, the vibration disturbance induced by the reaction wheels can magnify the satellite vibration when the rotating frequency of wheel meets the natural frequency of satellite structure. In order to provide an effective isolation of the reaction wheel disturbances, isolation performance of a hybrid vibration isolator is investigated. In this paper, hybrid vibration isolator that combines passive and active components is developed and its hybrid isolation performance using notch filter control is evaluated in single-axis. The hybrid isolation performance using notch filter control show additional performance improvement compared to the results using only passive components.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.55-65
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• 2017

PURPOSES : This study aimed to analyze the experimental and numerical behavior of warm mix asphalt pavement prepared using steel slag and RAP and to conduct economic analysis of pavement construction. METHODS : For developing high performance asphalt pavement, we performed three evaluations: fundamental analysis, experimental testing, and 3D finite element analysis. In particular, 3D finite element analysis was conducted on several pavement structures by adopting the results of experimental tests. RESULTS : Through the various evaluations, it was established that steel slag was effective for use as asphalt mixture aggregate. Moreover, asphalt mixture constituting steel slag and RAP demonstrated higher performance behavior compared with conventionally used asphalt mixture. Furthermore, based on the 3D FE modeling, we established that the developed asphalt pavement constituting steel slag and RAP can be utilized for thin layer pavement with comparable performance behavior. CONCLUSIONS :Warm mix asphalt pavement prepared using steel slag and RAP is more competitive and economic compared to hot-mix asphalt pavement. Moreover, it can be applied for preparing thin layer asphalt pavements with reasonable performance. The developed warm mix asphalt pavement prepared using steel slag and RAP can be an alternative pavement type with competitive performance based on the reasonable economic benefit it provides.

• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.193-204
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• 2012

This paper deals with an empirical analysis of the structural relationship among the factors such as quality management activities, organizational learning and firm performance of manufacturing corporations. The findings of the analysis are expected to make lots of contribution to manufacturing corporations establishing strategies for quality management activities and organizational learning. From the analysis, following conclusions and suggestions could be drawn: First, an analysis of the relationship between quality management activities and organizational learning showed that most activities of quality management turned out to exercise great influence upon the factors of organizational learning. This means that the activities of quality management will prompt the members of an organization to actively engage in learning activities individually, by team and organizationally, motivating them to spread such activities across the whole organization, leading ultimately to fundamental renovation of the very organization. Second, from an analysis of the relationship between organizational learning and firm performance, that is, financial and non-financial performances of a company, it was found that most factors of organizational learning have tremendous impact upon financial and non-financial performances of the company. Such result implies that decision and management of the things to be performed in the process of organizational performances are essential to determining firm performance because firm performance depend largely on the outcomes of organizational learning.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.613-620
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• 2020

COVID-19 pandemic has made the economy in Indonesia sluggish, especially Small and Medium Enterprises (SMEs). Simultaneously, the SMEs existence in Indonesia is fundamental and considered important by the government since it is able to assist numerous laborers and become an income source for the lower and middle classes of the community. The productivity of SME in a region will undeniably influence the availability of job and, of course, reduce the number of unemployed. Therefore, in this study, the researchers looked at how to improve SMEs performance to continue to exist amid the COVID-19 pandemic, by identifying the relationships between product characteristics, market competitive strategies, and the performance of SMEs. The research was done on SMEs in West Java, Indonesia. The example employed was Batik SMEs in Cirebon with at least 10 years in existence, and the total number of these SMEs was 165. As the basis of a quantitative approach, this study employed survey instruments by distributing a questionnaire. In analyzing the data, it utilized the structural equation modeling (SEM). The result showed a significant relationship between Product Characteristics, Market Competitive Strategy, and Price and Product Success Rate on SMEs Performance. This study's findings contribute to the SMEs performance literature.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.622-629
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• 2007

Some worker is occupationally exposed to cold and freezing environment. The cold stimuli in the working environment impose physiological and psychological loads on workers to decrease the task performance. The purpose of this study is to investigate the cold stimuli of cold and freezing stores widely used in Busan can make an effect on human's physiological responses and task performance, experimentally and analytically. In the experiment, 5 workers are selected as subjects, and then their skin temperatures of hand and ear, heart rates, blood pressure, and ring test performances in cold($3^{\circ}C$) and freezing($-22^{\circ}C$) stores were measured for 21 minutes and analyzed by using statistical method. It is observed that a physiological variation and the task performance are significantly influenced by an exposure time as well as a strength of cold stimuli. Also, it is suggested the exposure limiting times for the useful manual work and the performance predict model of the ring tasks. The result of this study will be useful for a fundamental data of which design the standard task time of manual tasks and solve the job placement problem of worker selection and placement in cold environment.

• Journal of the Society of Disaster Information
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• v.7 no.1
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• pp.21-31
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• 2011

The objectives of this study is replaced Silicafume with Metakaolin that is used to lightweight concrete to better performance. So, this study made high-performance lightweight concrete using Metakaolin and characteristics of the fundamental properties and chloride ion diffusion. Consequently, it is compressive strength and chloride ion penetration resistance is lower than lightweight concrete using Silicafume, the performance of compressive strength contrast Silicafume is about 88 to 95%. Also, this study got a content result because the chloride ion penetration resistance showed the performance in around 80 to 90%. As a result, this study insist that replacement ratio of Metakaolin is suitable for 10 to 15%.Silicafume and Metakaolin have similar characteristics. In addition, it is similar to the performance of alternative materials is possible.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.2
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• pp.137-147
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• 1995

This research is a preliminary study to improve the criteria of youth facilities which regulated in Youth Fundamental Act, with the method of Importance-Performance Analysis on youth facilities management. Evaluation inquiry had been made, and were collected from the youth facility managers who attended The Korean Youth Facility Managers' Seminar held on 24th Nov. 1994 at Pakdaljae Youth Center. The results are as follows; 1. Keep Up the Good Work : indoor facilities in community area, and outdoor facilities and accommodations in natural area are resulted in high in Importance and. Performance. They need to be operated constantly. 2. Concentrate Here : Counselling room, hobby room and outdoor meeting places in community area, and care room in natural area are perceived high in Importance but low in Performance. They need to provide proper leaders and equipment. 3. Low Priority : Care room, forest and outdoor facilities in community area, arid forest and folk playground in natural area are low in both Importance and Performance. So, it is considered that they are not necessary ones in both areas, but some outdoor facilities are so essential in natural area that they need to be provided properly. 4 Possible Overkill : Courtyard and library in community area, and outdoor facilities in natural area are low in Importance but high in Performance. They need to improve their importance through the development of applicable activity programs.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.365-373
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• 2021

Loan monitoring is a fundamental element of credit control. The importance of loan monitoring is to reduce loan defaults and to increase loan repayment performance. The ex-post monitoring can also increase the loan quality and thus a concern to many creditors in the market economy. This study identifies the role of ex-post monitoring on loan repayment performance in the context of rural Vietnam. Employing primary data from rural areas of Vietnam, this study investigates the impacts of ex-post monitoring on loan repayment performance of individual borrowers in terms of on-time loan repayment and the rate of loan repayment. Descriptions of borrower demographics, loan information, and ex-post monitoring show the initial picture of borrowers and loans in Vietnam's rural areas. Quantitative estimations that use the Probit and the Tobit model confirm the argument that better ex-post monitoring would result in better loan repayment performance in both on-time repayment and repayment rate. Thus, some policy suggestions have been made to improve the monitoring system in each financial institution. The study also indicates that some other factors too affect loan repayment performance such as borrower's characteristics (education, agricultural working area, and income) as well as loan's characteristics (loan size, maturity, and loan purpose).

• International Journal of Advanced Culture Technology
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• v.10 no.1
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• pp.230-235
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• 2022

This study is to select an optimal object detection algorithm for designing a self-checkout counter to improve the inconvenience of payment systems for products without existing barcodes. To this end, a performance comparison analysis of YOLO v2, Tiny YOLO v2, and the latest YOLO v5 among deep learning-based object detection algorithms was performed to derive results. In this paper, performance comparison was conducted by forming learning data as an example of 'donut' in a bakery store, and the performance result of YOLO v5 was the highest at 96.9% of mAP. Therefore, YOLO v5 was selected as the artificial intelligence object detection algorithm to be applied in this paper. As a result of performance analysis, when the optimal threshold was set for each donut, the precision and reproduction rate of all donuts exceeded 0.85, and the majority of donuts showed excellent recognition performance of 0.90 or more. We expect that the results of this paper will be helpful as the fundamental data for the development of an automatic payment system using AI self-service technology that is highly usable in the non-face-to-face era.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.3
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• pp.92-108
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• 2022

This study aims to intensively analyze the effect of ESG activities on the Business performance focused on Korean national flag carrier. The purpose of this study is to provide ESG activities to promote the sustainable development of Korean national flag carriers by verifying the impact of ESG on airline's business performance through mediate variables within the airline industry in consideration of the value and importance of ESG. A survey is conducted with a total of 272 users of Korea's national flag carrier both Korean air and Asiana airline. The collected data is analyzed using a structural equation model. The results show that ESG management has an indirect positive effect on business performance. It is expected that the results of this study may be employed as fundamental data to emphasize the relative importance of an ESG activities, thereby enhancing the Korean national flag carrier's business management and eliciting a positive impact on sustainable growth.