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        검색결과 106

        21.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to observe the wind load characteristics around two-dimensional rotor blade of small wind turbine under high wind speed. The CFD analysis on the blade shape of NACA-4418 is performed to understand the wind load(i.e., drag and lift coefficient). In the results, the drag and lift coefficient were estimated to be 0.013, 0.44, respectively, at the wind speed 35m/s(wind speed at the height of wind tower, z=70m) and angle of attack 3°. By using the lift, drag coefficient and the appropriate assumption of the blade length, the number of blade and the tip speed ratio(TSR), the proper blade shape was obtained. On the base of this basic study, various conditions for Reynolds number and aerodynamic analysis including angle of attack according to parametric test need to study more in the future. Also assessment for the blade need to study safety on wind pressure coefficient and distribution according to wind characteristics.
        4,000원
        22.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Control chart is representative tools of statistical process control (SPC). It is a graph that plotting the characteristic values from the process . It has two steps (or Phase). First step is a procedure for finding a process parameters. It is called PhaseⅠ. This step is to find the process parameters by using data obtained from in-controlled process. It is a step that the standard value was not determined. Another step is monitoring process by already known process parameters from PhaseⅠ. It is called Phase Ⅱ. These control chart is the process quality characteristic value for management, which is plotted dot whether the existence within the control limit or not. But, this is not given information about the economic loss that occurs when a product characteristic value does not match the target value. In order to meet the customer needs, company not only consider stability of the process variation but also produce the product that is meet the target value. Taguchi’s quadratic loss function is include information about economic loss that occurred by the mismatch the target value. However, Taguchi’s quadratic loss function is very simple quadratic curve. It is difficult to realistically reflect the increased amount of loss that due to a deviation from the target value. Also, it can be well explained by only on condition that the normal process. Spiring proposed an alternative loss function that called reflected normal loss function (RNLF). In this paper, we design a new control chart for overcome these disadvantage by using the Spiring’s RNLF. And we demonstrate effectiveness of new control chart by comparing its average run length (ARL) with x-R control chart and expected loss control chart (ELCC).
        4,000원
        23.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the manufacturing industry fields, thousands of quality characteristics are measured in a day because the systems of process have been automated through the development of computer and improvement of techniques. Also, the process has been monitored in database in real time. Particularly, the data in the design step of the process have contributed to the product that customers have required through getting useful information from the data and reflecting them to the design of product. In this study, first, characteristics and variables affecting to them in the data of the design step of the process were analyzed by decision tree to find out the relation between explanatory and target variables. Second, the tolerance of continuous variables influencing on the target variable primarily was shown by the application of algorithm of decision tree, C4.5. Finally, the target variable, loss, was calculated by a loss function of Taguchi and analyzed. In this paper, the general method that the value of continuous explanatory variables has been used intactly not to be transformed to the discrete value and new method that the value of continuous explanatory variables was divided into 3 categories were compared. As a result, first, the tolerance obtained from the new method was more effective in decreasing the target variable, loss, than general method. In addition, the tolerance levels for the continuous explanatory variables to be chosen of the major variables were calculated. In further research, a systematic method using decision tree of data mining needs to be developed in order to categorize continuous variables under various scenarios of loss function.
        4,000원
        24.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the production cycle in manufacturing process has been getting shorter and different types of product have been produced in the same process line. In this case, the control chart using coefficient of variation would be applicable to the process. The theory that random variables are located in the three times distance of the deviation from mean value is applicable to the control chart that monitor the process in the manufacturing line, when the data of process are changed by the type of normal distribution. It is possible to apply to the control chart of coefficient of variation too.  ,  estimates that taken in the coefficient of variation have just used all of the data, but the upper control limit, center line and lower control limit have been settled by the effect of abnormal values, so this control chart could be in trouble of detection ability of the assignable value. The purpose of this study was to present the robust control chart than coefficient of variation control chart in the normal process. To perform this research, the location parameter, xα, sα were used. The robust control chart was named Tim-CV control chart. The result of simulation were summarized as follows; First, P values, the probability to get away from control limit, in Trim-CV control chart were larger than CV control chart in the normal process. Second, ARL values, average run length, in Trim-CV control chart were smaller than CV control chart in the normal process. Particularly, the difference of performance of two control charts was so sure when the change of the process was getting to bigger. Therefore, the Trim-CV control chart proposed in this paper would be more efficient tool than CV control chart in small quantity batch production.
        4,000원
        25.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 다양한 냉동과 해동처리에 따른 계육 가슴살에 natural microflora, 접종된 L. monocytogenes와 C. jejuni 수와 미세구조 변화 구명을 위하여 연구를 수행하였다. −20℃ 송풍식 냉동처리구의 총 호기성 세균과 C. jejuni 수는 4.06 log CFU/g과 4.09 log CFU/g으로 대조구와 비교하여 각각 약 0.7 log CFU/g과 1.0 log CFU/g의 감소를 보였다. 한편, 계육 가슴살 접종된 L. monocytogenes 수는냉동방법과 냉동온도에 따라 유의적인 차이를 보이지 않았다. 4℃와 25℃ 송풍식 해동처리구의 총 호기성 세균수는 3.70 log CFU/g과 4.02 log CFU/g으로 측정되어 대조구와 비교하여 각각 0.72 log CFU/g과 0.40 log CFU/g 감소한 반면 25℃ 유수식 해동처리구의 총 호기성 세균 수는 해동과정에서 균수가 급격히 증가하여 5.78 log CFU/g으로 관찰되었다. 해동 중 C. jejuni 수 변화는 해동방법보다 해동온도에 영향을 받는 것으로 나타났다. 냉동-해동반복 5회 후 총 호기성 세균과 효모 및 곰팡이 수는 감소하여 각각 4.15 log CFU/g과 2.30 log CFU/g을 보였다. 계육 가슴살에 접종된 L. monocytogenes 수는 냉동-해동 반복처리에 유의적인 영향이 없었지만 C. jejuni 수는 냉동-해동 반복 횟수가 증가함에 따라 감소하는 경향을 보였다. 냉동-해동 반복이 증가함에 따라 근섬유 조직을 재 손상시켰으며 특히 냉동-해동 반복 5회 후에는 계육 가슴살 시료의 조직세포 외부뿐만 아니라 내부에서도 공간이 발생하였으며 불균일하게 찢어진 세포가 관찰되었다.
        4,000원
        26.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Due to advancements in technology and manufacturing capability, it is not uncommon that life tests yield no or few failures at low stress levels. In these situations it is difficult to analyse lifetime data and make meaningful inferences about product or system reliability. For some products or systems whose performance characteristics degrade over time, a failure is said to have occurred when a performance characteristic crosses a critical threshold. The measurements of the degradation characteristic contain much useful and credible information about product or system reliability. Degradation measurements of the performance characteristics of an unfailed unit at different times can directly relate reliability measures to physical characteristics. Reliability prediction based on physical performance measures can be an efficient and alternative method to estimate for some highly reliable parts or systems. If the degradation process and the distance between the last measurement and a specified threshold can be established, the remaining useful life is predicted in advance. In turn, this prediction leads to just in time maintenance decision to protect systems. In this paper, we describe techniques for mapping product or system which has degrading performance parameter to the associated classical reliability measures in the performance domain. This paper described a general modeling and analysis procedure for reliability prediction based on one dominant degradation performance characteristic considering pseudo degradation performance life trend model. This pseudo degradation trend model is based on probability modeling of a failure mechanism degradation trend and comparison of a projected distribution to pre-defined critical soft failure point in time or cycle.
        4,000원
        27.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        ISO 9001, quality management system, is widely known as advancing internal efficiency and productivity in various industry. As a result, the number of companies that have adopted ISO 9001’s certification have been increasing continuously year by year since ISO 9000’ family standard was published in 1987s. This fact shows that a lot of businesses are trying to get the accreditation for improving the competitiveness of quality. The purpose of this study is to present that ISO 9001’s certification motives affect to the requirement’s implementation and show that the execution of requirements influences on management performance in the small manufacturer. In order to carry out this research, we obtained 96 survey sheets and inspected twenty assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factors of certification motive influence on the requirement’s implementation except resources management. Second, the two elements of ISO 9001 requirement, resources management and product realization, have an important effect on the operational performance and financial performance considerably in the companies that choose the internal motive. Finally, the two requisites of ISO 9001 requirement, resources management and measurement, analysis and improvement, affect to the operational performance and financial performance significantly in the businesses that select the external motive. Based on the results, the companies that choose the internal motive have a good performance to execute the ISO 9001 requirements. Also, to implement the requirements of ISO 9001 is helpful for the companies to produce the operational and financial performance.
        4,000원
        29.
        2015.10 구독 인증기관 무료, 개인회원 유료
        Control chart is a graph of plotting dot in the process characteristic values. It is a statistical technique that can be known whether or not the in-control state in this step. In many companies have use as a statistical process control(SPC) tool. Control chart is the management process quality characteristic value, which is plotted dot is whether the existence within the control limits. But, this is not given information about the economic loss that occurs when a product is produced characteristic value does not match the target value of the process. In that sence, expected loss control chart(EL control chart) is very effective process control tool. Because it is a process control chart in consideration to economic loss. The EL control chart is using the quadratic loss function of Taguchi. However, Taguchi’s quadratic loss function is simple quadratic curve. It is difficult to realistically reflect the increased amount of loss that due to a deviation from the target value. In this paper, we design a new control chart using the reflected normal loss function(RNLF). And we demonstrate its effectiveness by using the control chart performance comparison of EL control chart.
        4,000원
        30.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Control charts are generally used for process control, but the role of traditional control charts have been limited in case of a non-contaminated process. Traditional x-s control chart has not been activated well for such a problem because of trying to control processes as center line and control limits changed by the contaminated value. This paper suggests modified x-s control chart based on robust estimation. In this paper, we consider the trimmed mean of the sample means and the trimmed mean of the sample standard deviations. By comparing with ARL value, the responding results are decided. The comparison resultant results of traditional control chart and modified control chart are contrasted.
        4,000원
        31.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to introduce a empirical study of using Taguchi Method for the Entrepreneurial Orientation and Financial Performance. In this study, three factors of Entrepreneurial Orientation, innovation, pro-activity and risk taking, are used of the control factors and an element, period of establishment, is chosen as a noise factor. In order to carry out this research, we obtained 200 survey sheets and performed the reliability and validity analysis of the questionnaires and then the experiment was conducted by Taguchi's experimental design. To improve Financial Performance under the noise factor of period of establishment, optimal condition are as follows; the two factors of Entrepreneurial Orientation, innovation, pro-activity should be maintained to a high level. Also, other factor, risk taking should be performed as the level that the company has maintained. Through this paper, we find out that Taguchi method is applicable for analysis of questionnaire.
        4,000원
        32.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper is present the Technology Orientation affects to Enterprise Management Performance. In order to carry out this research, we obtained 212 survey sheets and inspected ten assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factor of Technology Orientation, research development activity, affects to all factor of Enterprise Management Performance significantly. Second, the factor of Technology Orientation, research development environment, only effect on the technology performance. Third, research development ability is affect to technology performance and new product performance that factor of Enterprise Management Performance. Finally, technology industrialization ability isn’t affects to Enterprise Management Performance significantly. Based on the results, we are recommendations for small and medium-sized manufacturing enterprises.
        4,000원
        33.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to present the Market Orientation affects to Enterprise Management Performance. In order to carry out this research, we obtained 212 survey sheets and inspected ten assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factor of Market Orientation, intelligence generation, doesn’t influence on the Enterprise Management Performance significantly. Second, the element of Market Orientation, information dissemination, doesn’t have an important effect on the Enterprise Management Performance. Finally, the requisite of Market Orientation, information response, affects to Enterprise Management Performance significantly. Based on the results, the parts with intelligence generation and information dissemination will be improved in the manufacturer of the small businesses.
        4,000원
        34.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In industrial situation, electronic and electro-mechanical systems have been using different type of batteries in rapidly increasing numbers. These systems commonly require high reliability for long periods of time. Wider application of battery for low-power design as a prime power source requires us knowledge of failure mechanism and reliability of batteries in terms of load condition, environment condition and other explanatory variables. Battery life is an important factor that affects the reliability of such systems. There is need for us to understand the mechanism leading to the failure state of battery with performance characteristic and develop a method to predict the life of such battery. The purpose of this paper is to develope the methodology of monitoring the health of battery and determining the condition or fate of such systems through the performance reliability to predict the remaining useful life of primary battery with load condition, operating condition, environment change in light of battery life variation. In order to evaluate on-going performance of systems and subsystems adopting primary batteries as energy source, The primitive prototype for performance reliability analysis device was developed and related framework explained.
        4,000원
        35.
        2014.05 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to present the Market Orientation effects on Enterprise Management Performance. In order to carry out this research, we obtained 212 survey sheets and inspected ten assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factor of Market Orientation, intelligence generation, don’t influence on the Enterprise Management Performance significantly. Second, the element of Market Orientation, information dissemination, don’t have an important effect on the Enterprise Management Performance. Finally, the requisite of Market Orientation, information response, affects to Enterprise Management Performance significantly. Based on the results, the parts with intelligence generation and information dissemination will be improved in the manufacturer of the small businesses.
        4,000원
        36.
        2014.05 구독 인증기관 무료, 개인회원 유료
        Multivariate control charts are widely needed to monitor the production processes in various industry. Among the several multivariate control charts, control chart have been used of the typical technique. The control chart shows a statistic that represents observed variables and monitors the process through the statistic. In this case, the statistic generally have the limit that any variables affect to that statistic. To solve this problem, some studies have been progressed in the meantime. The representative method is to disassemble total statistic into each of the variable value and make a decision the parameters with large values than threshold value as a main cause. However, the means is requested to follow the normal distribution. To settle this problem, the bootstrap technique that don't be needed the probability distribution was introduced in 2011. In this paper, I introduced the detection technique of the fault variables using multiple regression analysis. There are two advantages; First, it is possible to use less samples than the ascertainment technique applying to bootstrap. Second, the technique using the regression analysis is easy to apply to the actual environment because the global threshold value is used.
        4,000원
        37.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Control charts are generally used for process control, but the role of traditional control charts have been limited in case of a contaminated process. Traditional x control charts have not been activated well for such a problem because of trying to control processes as center line and control limits changed by the contaminated value. This paper is to propose robust x control charts which is considering a location parameter in order to respond to contaminated process. In this paper, we consider x, that is trimmed rate; typically ten percent rate is used. By comparing with p, ARL value, the responding results are decided. The comparison resultant results of proposed two control charts are shown and are well contrasted.
        4,000원
        38.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Process Capability Index (PCI) is useful Statistical Process Control (SPC) tool that is measure of process diagnostic and assessment tools widely use in industrial field. It has advantage of easy to calculate and easy to use in the field. Cp and Cpk are traditional PCIs. These are only considers of process variation. These are not given information about the characteristic value does not match the target value of the process. Studies of this process capability index by many scholars actively for supplement of its disadvantage. These studies to evaluate the capability of situation of various field has presented a new process capability index. Cpm is considers both the process variation and the process deviation from target value. And Cpm + is considers economic loss for the process deviation from target value. In this paper development of new process capability index that is Taguchi's quadratic loss function by applying the expected loss. And check the correlation between existing traditional process capability index (Cpk) and new one. Finally, we propose the criteria for classification about developed process capability index.
        4,000원
        39.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to present that the strategic orientation affects on the green management performance. In order to carry out this research, the samples are reviewed and the ten hypotheses are verified reliably and appropriately. The results of the verification are summarized as follows: First, strategic directivity affects on the green management performance significantly. Second, two factors of the strategic directivity, customer orientation and technology orientation affect on the green performance relatively high. Finally, the two elements of the strategic orientation, competitive orientation and technology orientation affect on the financial performance significantly. In conclusion, this study shows all of the factors of the strategic orientation affect on the green management. In order to get the effective green management, education programs should be conducted by social support systems.
        4,000원
        40.
        2013.10 구독 인증기관 무료, 개인회원 유료
        Process Capability Index(PCI) is useful Statistical Process Control(SPC) tool that is measure of process diagnostic and assessment tools widely use in industrial field. It has advantage of easy to calculate and easy to use in the field. Cp and Cpk are traditional PCIs. These are only considers of process variation. These are not given information about the characteristic value does not match the target value of the process. Studies of this process capability index by many scholars actively for supplement of its disadvantage. These studies to evaluate the capability of situation of various field has presented a new process capability index. Cpm is considers both the process variation and the process deviation from target value. And Cpm+ is considers economic loss for the process deviation from target value. In this paper development of new process capability index that is Taguchi's quadratic loss function by applying the expected loss. And check the correlation between existing traditional process capability index(Cpk) and new one. Finally, we propose the criteria for classification about developed process capability index.
        4,000원
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