• Journal of the Korean Wood Science and Technology
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• 제48권4호
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• pp.503-512
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• 2020

Using Na₂CO₃ versus NaCl as chemical activator, we compared the quality of activated carbon produced from oil palm fronds as raw material. These activators were selected for comparison because both are readily available and are environmentally friendly. In the manufacturing, we used Indonesian National Standard (SNI 06-3730-1995) parameters. For the quality comparison, we determined activated-carbon yield, moisture, ash, volatiles, and fixed-carbon contents; and adsorption capacity of iodine. The best characteristics, assessed by morphological surface analysis and Fourier transform infrared (FTIR) spectral analysis, were observed in the carbon activated by Na₂CO₃ at an activator concentration of 10% and carbonization temperature of 400 ℃. The results were as follows: activated-carbon yield, 84%; water content, 8.80%; ash content, 2.20%; volatiles content, 14.80%; fixed-carbon content, 68.60%; and adsorption capacity of iodine, 888.51 mg/g. Identification using the FTIR spectrophotometer showed the presence of the functional groups O-H, C=O, C=C, C-C, and C-H in the Na₂CO₃-activated carbon.

• Geomechanics and Engineering
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• 제32권5호
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• pp.503-512
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• 2023

In tunneling projects, a significant part of the costs is spent on segment production. By more economically producing, the cost of tunnel construction can be greatly reduced, especially in long and large-diameter tunnels. In the present study, the effect of using the Carousel method in the improvement of the production system performance compared to the conventional Static system has been studied. To carry out the research, a quantitative comparison of cost and production time was carried out for two production methods using the available documentation. The opinions of experts have been obtained using questionnaires and qualitative comparison of cost, time and production quality was done by implementation of statistical analysis. The SPSS software and the univariate t-test were used to analyze the questionnaires. According to the results of statistical analysis with SPSS, the use of the Carousel method will reduce production time and costs along with increasing manufacturing quality. According to the documentation analysis, the Carousel method reduces the cost of production by almost 30% and leads to a reduction of the production time to approximately 40% of the Static moulds system. The Carousel method has a higher production rate, efficiency, and better performance. Research into quantifying the benefits of Carousel method in the production system performance is very limited. This comparison is based on real information from the under construction Tabriz Metro project. This article can be very helpful in choosing the best production method.

• 한국소음진동공학회논문집
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• 제22권3호
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• pp.234-243
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• 2012

In this paper, a sound quality indices for the evaluation of vehicle intake and exhaust noise were developed through a correlation analysis of objective measurement data and subjective evaluation data. At first, intake and exhaust orifice noise were measured at the wide-open throttle sweep condition. And then, acoustic transfer function between intake orifice noise and interior noise at the steady state condition was measured. Also, acoustic transfer function for exhaust system was measured as the same method. Simultaneously, subjective evaluation was carried out by the paired comparison and semantic differential method by 27 engineers. Next, the correlation analysis between the psycho-acoustic parameters derived from the measured data and the subjective evaluation was performed. The most critical factor was determined and the corresponding sound quality index for the intake and exhaust noise was obtained from the multiple factor regression method. At last, the effectiveness of the proposed index was investigated.

• 한국소음진동공학회논문집
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• 제15권8호
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• pp.945-953
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• 2005

The purpose of this paper is to develop a linear regression model for the sound quality index of vehicle Interior noise. For this, objective measurement data of the vehicles driving in acceleration was measured. On the basis of analysis, psychoacoustic parameters were extracted and subjective evaluation was performed by noise and vibration expert evaluators. For the subjective evaluation, the paired comparisons and the semantic differential methods were used to evaluate sound quality of vehicle interior noise. By the paired comparison which evaluate two pairs of vehicle interior noise, the preference was estimated. With the semantic differential and the factor analysis, it was evaluated words of two pairs which expressed appropriately the sense of evaluator about noise source. Therefore the characteristics of the sound qualify for the vehicle were differentiated. From the results of both the correlation analysis and the multiple factor regression analysis, the sound quality evaluation model for the sense of human hearing was derived and indexed.

• 한국항공운항학회지
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• 제18권3호
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• pp.55-69
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• 2010

The role of airports in the metropolitan area in Korea is very important which is located on the center of Northeast Asia considered as the highest potential growth continent in the world air transport market. This study includes comparison on service quality between Gimpo Airport and Incheon Airport which are indicated as multi-airport system in the metropolitan area appraised by passengers from Korea, Japan and China, and analysis on primary factors of airport service which affect the customer satisfaction and loyalty. The service quality appraised in the order of Chinese, Korean, and Japanese and the analysis result indicated that the service quality factors which influence on customer satisfaction and loyalty were all different among passengers from three countries. Information service was the priority factor for customer satisfaction to Chinese and Korean, but Japanese considered that personal service was the most important factor. This research paper tried to provide many current issues and guides to operational strategy including plan for the specialized routes of multi-airport system in domestic metropolitan area.

• 한국의류학회지
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• 제37권5호
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• pp.631-644
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• 2013

This study investigates the gaps between ideal and actual corporate social responsibility (CSR) by comparing levels of CSR perceptions and examining the relationship differences between CSR perception, perceived quality, and affective trust from a consumer perspective. Data from 315 adult samples were collected through a nationwide online survey. In order to compare ideal and actual CSR, the study employed the approach of latent means analysis (LMA) and multi-group comparisons within the framework of a structural equation modeling (SEM). The result of latent means comparison showed significant differences of perceptions on fashion CSR across ideal and actual contexts. Only actual economic CSR was evaluated higher than in the ideal context and the effect size of inter-management CSR was the largest among seven domains. Multi-group SEM revealed a significant discrepancy between ideal and actual CSR structural models that exhibited relationships of CSR perception, perceived quality, and affective trust. The paths from internal management and ethical CSR to perceived quality and from economic and philanthropy CSR to affective trust were different across ideal and actual contexts. Implying the understanding of consumer CSR perceptions and the mediating role of perceived quality, this study suggests that marketers narrow the gap between ideal and actual CSR.

• 품질경영학회지
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• 제43권3호
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• pp.313-326
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• 2015

Purpose: The terminology of "policy" or "quality policy" is widely used in quality management areas. But few people know and use that word with the accurate concept. This paper compares the concepts and suggests the contents for quality policy and quality strategy. Methods: This paper compares the concepts between policy and strategy through the literatures and suggests the contents for quality policy and quality strategy by exploratory study. Results: This paper suggests the contents for quality policy and quality strategy which are useful to establish the quality planning in companies. Conclusion: Strategy and policy are intimately related, and so confused in applications, therefore distinguishing both concepts clearly is necessary for effective use of them. This paper will help the right use of both concepts by showing the examples.

• 융합신호처리학회논문지
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• 제21권2호
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• pp.92-100
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• 2020

현재 수중 촬영을 통해 물속이나 바다 속을 촬영하려는 수요는 매우 빠르게 늘어나고 있다. 방송용 수중 촬영, 레저 및 스포츠용, 군사 및 작전용 등 그 적용 범위 또한 빠르게 늘어나고 있다. 그중 특별히 우리는 선박 선저에 부착된 해양 생물들을 촬영하고 검사하기 위해 수중 드론에 사용 될 최적의 카메라를 선정한다. 3대의 카메라들을 성능적으로 비교하는데 수중 촬영이라는 특별한 상황에서 객관적 기준, 주관적 기준을 사용하여 비교 및 평가한다. 본 연구는 수중 촬영이라는 특이한 상황에서 카메라의 해상도와 같은 성능적 기준이 객관적 기준과 주관적 기준에도 부합하는지를 확인한다. 그리고 훌륭한 화질 제공에는 영상을 보정하는 필터 외에도 적절한 카메라 선정이 중요하다는 점을 보여준다. 이 연구 후에도 좀 더 다양한 카메라들을 이용한 연구를 통해서 수중 촬영용 카메라 화질 비교의 적절한 기준을 제시해 줄 수 있을 것이다.

• 품질경영학회지
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• 제31권1호
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• pp.76-89
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• 2003

Recently, CMM have been recognized as a critical factor to validate the competitiveness of software organizations, even if the organizations have already achieved the ISO9001 certification. Furthermore, the new version of ISO9001:2000 is being required instead of ISO9001:1994. Both CMM and ISO9001 have a common point that they pursuit quality improvement for the organizations processes and products. Therefore, it is important to understand the similarities of specific requirements between the two models in software organizations which attempt to employ both of the models. From this background, this paper compares CMM and ISO9001 by considering the versions in 1994 and 2000 of ISO9001. The results of this research are likely to help software organizations ma]fe a decision for a strategy to adopt CMM and ISO9001.

• 한국물환경학회지
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• 제20권4호
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• pp.352-356
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• 2004

Variations of water quality parameters were investigated for last 13 years in Han river. Deviation from 3 month moving average was suggested for the variation analysis. Many parameters of mainstream and tributaries showed similar monthly fluctuations. Suspended solid of mainstream showed higher fluctuation than that of tributaries due to summer flood. Contrarily, the organic parameters such as BOD, COD, and TN showed lower fluctuations in the mainstreams. The magnitude of deviation was in the order of pH < DO, COD, temp. < BOD, TN < TP, SS. Strong correlation was found in BOD data of adjacent sites. Main sites showed low deviation in comparison to adjacent common sites of mainstream (1:2.4). Mainstream showed low deviation in comparison to tributaries (1:1.7). Seasonal tendency of monthly BOD was confirmed using autocorrelation function. The deviation was in inverse proportion to the magnitude of BOD.