간행물

한국산업경영시스템학회지 KCI 등재 Journal of Society of Korea Industrial and Systems Engineering

권호리스트/논문검색
이 간행물 논문 검색

권호

Vol. 41 No. 1 (2018년 3월) 13

1.
2018.03 구독 인증기관 무료, 개인회원 유료
Current evaluation practices for IT projects suffer from several problems, which include the difficulty of self-explanation for the evaluation results and the improperly scaled scoring system. This study aims to develop a methodology of opinion mining to extract key factors for the causal relationship analysis and to assess the feasibility of quantifying evaluation scores from text comments using opinion mining based on big data analysis. The research has been performed on the domain of publicly procured IT proposal evaluations, which are managed by the National Procurement Service. Around 10,000 sets of comments and evaluation scores have been gathered, most of which are in the form of digital data but some in paper documents. Thus, more refined form of text has been prepared using various tools. From them, keywords for factors and polarity indicators have been extracted, and experts on this domain have selected some of them as the key factors and indicators. Also, those keywords have been grouped into into dimensions. Causal relationship between keyword or dimension factors and evaluation scores were analyzed based on the two research models-a keyword-based model and a dimension-based model, using the correlation analysis and the regression analysis. The results show that keyword factors such as planning, strategy, technology and PM mostly affects the evaluation result and that the keywords are more appropriate forms of factors for causal relationship analysis than the dimensions. Also, it can be asserted from the analysis that evaluation scores can be composed or calculated from the unstructured text comments using opinion mining, when a comprehensive dictionary of polarity for Korean language can be provided. This study may contribute to the area of big data-based evaluation methodology and opinion mining for IT proposal evaluation, leading to a more reliable and effective IT proposal evaluation method.
4,000원
2.
2018.03 구독 인증기관 무료, 개인회원 유료
This paper investigated relationship among internal as well as external motive to receive the ISO 13485 certification, countermeasure to the certification examination, active reception/execution level of the certification, and operational as well as financial performance of the medical device related enterprises in South Korea which received and are maintaining the ISO 13485 certification. SEM (structural equation model) and related analyses using AMOS 21.0 and SPSS 21.0 have been applied to verify the hypotheses of the research. Result of the research showed that internal as well as external motive for certification positively(+) affects active reception/execution level of the certification as well as countermeasure to the certification examination. The reception/execution level of the certification also positively(+) affects on the operational as well as financial performance of the certified enterprises. However, countermeasure to the certification examination was found out to negatively(-) affects the active reception/execution level of the certification and we can interpret that relatively more countermeasure to the certification examination burdens the employees of the enterprise, causing them to be less active on the reception/execution level of the certification. This research found that an enterprise’s operational/financial performance improves when an enterprise introduces the ISO 13485 certification standard spontaneously on the purpose of improving its system and the certification system is applied to the enterprise actively, not passively. This research emphasizes the need to recognize the difference of the level of active reception implication among members of an enterprise according to the motive of introduction of the certification system.
4,500원
3.
2018.03 구독 인증기관 무료, 개인회원 유료
Since a social networking service (SNS) isconsidered as an effective means to communicate and interact with customers, companies are trying to utilize SNS effectively. There is a lack of theory relating to the attributes of SNS. This study aims to investigate the attributes of SNS to classify SNS. Based on the social network theory, and previous studies on internet, blog, homepage, communication attributes, this study proposes the seven attributes to classify SNS: interaction, communication, entertainment, information, sharing, intimacy and connection. A pre-test, a pilot test and a main test are conducted. In the main test, 239 SNS users are participated. Through a factor analysis this study verifies the seven attributes of SNS. An analysis of variance with multiple comparisons of Scheffé method identifies that three attributes, interaction, communication and connection, are found to play significant roles to differentiate SNS. Looking at the overall mean values of the SNS by attribute, interaction, sharing, entertainment, intimacy and communication were relatively high in Facebook. Facebook showed higher values in attributes of interaction, sharing, entertainment, intimacy and communication. Twitter shows the relatively high scores for information and connection. Regarding interaction, Facebook shows higher scores than Twitter and Cyworld. For connection, Cyworld showed a significantly lower score than Twitter and Facebook. Cyworld was separated from the others in the light of communication. Cyworld is relatively weak in communication as it is limited to the message exchanges. The results will help in identifying major attributes for each SNS and classifying SNS.
4,800원
4.
2018.03 구독 인증기관 무료, 개인회원 유료
In the satellite operation phase, a ground station should continuously monitor the status of the satellite and sends out a tasking order, and a satellite should transmit data acquired in the space to the Earth. Therefore, the communication between the satellites and the ground stations is essential. However, a satellite and a ground station located in a specific region on Earth can be connected for a limited time because the satellite is continuously orbiting the Earth, and the communication between satellites and ground stations is only possible on a one-to-one basis. That is, one satellite can not communicate with plural ground stations, and one ground station can communicate with plural satellites concurrently. For such reasons, the efficiency of the communication schedule directly affects the utilization of the satellites. Thus, in this research, considering aforementioned unique situations of spacial communication, the mixed integer programming (MIP) model for the optimal communication planning between multiple satellites and multiple ground stations (MS-MG) is proposed. Furthermore, some numerical experiments are performed to verify and validate the mathematical model. The practical example for them is constructed based on the information of existing satellites and ground stations. The communicable time slots between them were obtained by STK (System Tool Kit), which is a well known professional software for space flight simulation. In the MIP model for the MS-MG problems, the objective function is also considered the minimization of communication cost, and ILOG CPLEX software searches the optimal schedule. Furthermore, it is confirmed that this study can be applied to the location selection of the ground stations.
4,200원
5.
2018.03 구독 인증기관 무료, 개인회원 유료
Intermittent demand is a demand with a pattern in which zero demands occur frequently and non-zero demands occur sporadically. This type of demand mainly appears in spare parts with very low demand. Croston’s method, which is an initiative intermittent demand forecasting method, estimates the average demand by separately estimating the size of non-zero demands and the interval between non-zero demands. Such smoothing type of forecasting methods can be suitable for mid-term or long-term demand forecasting because those provides the same demand forecasts during the forecasting horizon. However, the smoothing type of forecasting methods aims at short-term forecasting, so the estimated average forecast is a factor to decrease accuracy. In this paper, we propose a forecasting method to improve short-term accuracy by improving Croston’s method for intermittent demand forecasting. The proposed forecasting method estimates both the non-zero demand size and the zero demands’ interval separately, as in Croston’s method, but the forecast at a future period adjusted by binomial weight according to occurrence probability. This serves to improve the accuracy of short-term forecasts. In this paper, we first prove the unbiasedness of the proposed method as an important attribute in forecasting. The performance of the proposed method is compared with those of five existing forecasting methods via eight evaluation criteria. The simulation results show that the proposed forecasting method is superior to other methods in terms of all evaluation criteria in short-term forecasting regardless of average size and dispersion parameter of demands. However, the larger the average demand size and dispersion are, that is, the closer to continuous demand, the less the performance gap with other forecasting methods.
4,000원
6.
2018.03 구독 인증기관 무료, 개인회원 유료
The up-to-date business environment for Korean manufacturers is very complex and rapidly changing. Especially, the companies have faced with various changes derived from small quantity batch production, diversification of customer demands, and short life cycles of products. Consequently, the Korean manufacturing companies are in need of more efficient production planning and scheduling techniques. In this paper, the research trend of scheduling techniques is investigated to provide relevant information to researchers in this field. Furthermore, some implications for future researches are presented regarding literatures published in Korea over the last 10 years. This paper presents an entire investigation into Korean research works on scheduling (2,569 papers) that are published from 2007 to 2016. Especially, detailed analysis was carried out in the following three industry : 1) semiconductor, 2) shipbuilding and 3) automobile. In this paper, approaches to scheduling presented in the literature are categorized into the following three categories : 1) application, 2) algorithm, and 3) simulation modeling. First, in the semiconductor industry, scheduling techniques related to semiconductor cleaning processes, photolithography processes, chemical processes, transport and transport equipment have been found to be dominant. Second, the shipbuilding industry is focused on assembly processes, transporter, crane and various existing production management system. On the other hand, the scheduling research of the automobile industry is mainly focused on the vehicle movement routing and procurement supply-chain planning algorithm in terms of logistics. The conclusion of this study are expected to provide many implications for various types of academic and practical follow-up studies related to scheduling in consideration of main characteristics of semiconductor, shipbuilding and automobile industries.
4,200원
7.
2018.03 구독 인증기관 무료, 개인회원 유료
Korea’s five leading industries-chemical, automobile, shipbuilding, metal and electronics-have been the growth engines of the Korean economy for the last 30 years. However, with their performance weakening in the past few years, Korea’s annual growth rate has dropped to less than 2%. Just as the Japanese economy struggled through the lost decades, Korea’s leading industries have been facing signals of arriving at a Strategic Inflection Point (“SIP”) since the mid-2000s. The objective of this study is to present an appropriate value strategy for Korean firms in leading industries to gain sustainable competitive advantages. This paper examines the following issues : First, it diagnoses the signs and timing of SIP for the five leading industries. Second, this study examines 78 Korean and Japanese firms in order to understand the adaptation strategies of the highest and lowest performing firms from a value strategy point of view. Third, it empirically analyzes the correlation between the indicators of value strategy and the accounting performances of the Korean and Japanese firms. The data set used in the cluster analysis were collected from KISLINE database of NICE Information Service and annual reports. The findings in the case analyses of high and low performing companies show that high value-added specialty chemical materials and electronic component manufacturers that had a strong focus on value creation were defined as high performing companies. And in the cosmetic and automobile industries, companies with a strong emphasis on value appropriation gained high performance. Furthermore, the study conducted a cluster analysis based on two indicators R&D and advertisement expense. The analysis shows that a significant gap exists in the operating incomes among three groups classified under the value strategy. The study recommends that Korean firms are requested to increase R&D expenditure, conduct M&A and collaborate with companies that own source technologies to narrow the technology gap and improve their segment portfolio from commodity to value-added products.
4,600원
8.
2018.03 구독 인증기관 무료, 개인회원 유료
In this paper, we propose an Elman recurrent neural network to predict and analyze a time series of power energy consumption. To this end, we consider the volatility of the time series and apply the sample variance and the detrended fluctuation analyses to the volatilities. We demonstrate that there exists a correlation in the time series of the volatilities, which suggests that the power consumption time series contain a non-negligible amount of the non-linear correlation. Based on this finding, we adopt the Elman recurrent neural network as the model for the prediction of the power consumption. As the simplest form of the recurrent network, the Elman network is designed to learn sequential or time-varying pattern and could predict learned series of values. The Elman network has a layer of “context units” in addition to a standard feedforward network. By adjusting two parameters in the model and performing the cross validation, we demonstrated that the proposed model predicts the power consumption with the relative errors and the average errors in the range of 2%~5% and 3kWh~8kWh, respectively. To further confirm the experimental results, we performed two types of the cross validations designed for the time series data. We also support the validity of the model by analyzing the multi-step forecasting. We found that the prediction errors tend to be saturated although they increase as the prediction time step increases. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric and the gas energies.
4,000원
9.
2018.03 구독 인증기관 무료, 개인회원 유료
With the development of industrial technology and science, production and manufacturing facilities have been enhanced and improved, and the importance of the safety of workers has also been regulated and limited by various safety management methods. As a way to secure the safety of the workers from the production facility, the fail-safe and fool-proof methods are now being applied. Any possible insecure behavior and unsafe conditions can be removed by adopting the standards and specifications that are now secure the safety of workers and equipment. This research analyzes EN ISO 13849-1 international and European standards during CE certification. In order to secure acceptable reduced risks, the risk assessment process of ISO 12100 and the processes for reducing its risk are applied. In the current ISO 13849-1 standard, the criteria for the required performance level PLr (Required Performance Level) for the applicable risk and safety functions through the risk assessment are subjective and not subdivided. Therefore, the evaluation criteria are likely to cause judge’s judgement error due to qualitative judgement. This research focuses on evaluation and acceptable performance level setting for the safety circuit of the equipment. We propose an objective and specific evaluation criteria to secure safety, and the proposed evaluation criteria are applied to the case study of the safety circuit for the equipment. In order to secure the safety of the entire safety circuit, the improvement of the MTTFd and DC level related to the SRP/CS (Safety-Related Parts of Control Systems)’ lifetime is required for the future research.
4,000원
10.
2018.03 구독 인증기관 무료, 개인회원 유료
This paper seeks to present a multi-control method that can contribute to effective control of the production line with multiple bottleneck processes. The multi-control method is the production system that complements shortcomings of CONWIP and DBR, and it is designed to determine the raw material input according to the WIP level of two bottleneck processes and WIP level of total process. The effectiveness of the production system developed by applying the multi-control method was verified by the following three procedures. Raw material input conditions of the multi-control method are as follows. First, raw materials are go into the production line when the number of the total process WIP is lower than established number of WIP in total process and first process is idle. Second, raw materials are introduced when the number of WIP of two bottleneck processes is lower than the established number of WIP of each bottleneck process. Third, raw materials are introduced when the first process and in front of bottleneck process are idle even if the number of WIP in the total process is less than established number of WIP of the total process. The production line with two bottleneck processes was selected as the condition for production environment, and the production process modeling of CONWIP, DBR and multi-control production method was defined according to the production condition. And the optimum limited WIP level suitable for each system was obtained by applying a genetic algorithm to determine the total limited number of WIP of CONWIP, the limited number of WIP of DBR bottleneck process, the number of WIP in the total process of multi-control method and the limited number of WIP of bottleneck process. The limited number of WIP of CONWIP, DBR and multi-control method obtained by the genetic algorithm were applied to ARENA modeling, which is simulation software, and a simulation was conducted to derive result values on the basis of three criteria such as production volume, lead time and number of goods in-progress.
4,000원
11.
2018.03 구독 인증기관 무료, 개인회원 유료
Machines and facilities are physically or chemically degenerated by continuous usage. One of the results of this degeneration is the process mean shift. By the result of degeneration, non-conforming products and malfunction of machine occur. Therefore a periodic preventive resetting the process is necessary. This type of preventive action is called ‘preventive maintenance policy.’ Preventive maintenance presupposes that the preventive (resetting the process) cost is smaller than the cost of failure caused by the malfunction of machine. The process mean shift problem is a field of preventive maintenance. This field deals the interrelationship between the quality cost and the process resetting cost before machine breaks down. Quality cost is the sum of the non-conforming item cost and quality loss cost. Quality loss cost is due to the deviation between the quality characteristics from the target value. Under the process mean shift, the quality cost is increasing continuously whereas the process resetting cost is constant value. The objective function is total costs per unit wear, the decision variables are the wear limit (resetting period) and the initial process mean. Comparing the previous studies, we set the process variance as an increasing concave function and set the quality loss function as Cpm+ simultaneously. In the Cpm+, loss function has different cost coefficients according to the direction of the quality characteristics from target value. A numerical example is presented.
4,000원
12.
2018.03 구독 인증기관 무료, 개인회원 유료
Recently, service quality must reflect several demands of customers who show rapid and various changes so as to be compared with the past. So, objective and rapid measuring methods for service quality are necessary. For them, first of all, service company must calculate their standard of service quality accurately by measuring service quality exactly. Kano classified the degree of influence that is the degree of correspondence of the quality attributes of products and services to the subjective satisfaction of customers. As a result, the types of qualities are classified as attractive, must be, one dimensional, and indifference attributes. They have been widely used quality attributes in various industrial fields up to now. However, Kano model has a limit that it ignores the characters of the next frequent numbers even though there are not much gap comparing to the most frequent number in the questionnaire answers. The limit is attributed to the character of Kano model that the most frequent number is accepted as the only quality character. Timko calculated the customer satisfaction coefficient by using Kano’s method and studied the differences in quality character by classifying the quality characteristics in a graphical way through the relationship between the satisfaction and the dissatisfaction coefficient. In this study, we used the quality level determination method of the 7-point Likert scale, which takes the weight into account, to complement the deficiencies of the existing Kano model. We also developed and applied a Potential Satisfaction Level (P) and Potential Customer Demand Improvement (PCDI) Index to present a new approach to the determination of service quality attributes. To measure the level of potential service satisfaction and to understand the degree of improvement, we collected specimens of 51 participants who has been trained in the National Strategy Business Training Program, which has been managed by government agent, and analyzed the results.1)
4,000원
13.
2018.03 구독 인증기관 무료, 개인회원 유료
As The Fourth Industrial Revolution and Intelligent Information Age came into full-scale, the policy of open government data has become a hot topic for each country. The United States, the United Kingdom, and other countries are shifting policy direction to “creating value” of open government data. Also, in the age of the digital economy where the data market is soaring, open government data is gradually being recognized as a new raw material for new business and start-ups. In addition, Korea ranked first in the OECD open government data evaluation twice in a row, and was highly evaluated in the international evaluation. However, domestic firms are still lacking in qualitative openness of government data, data is dispersed among institutions, lack of public-private data linkage, and development of app-oriented development. This study attempts to analyze major national policies for the creation of a data ecosystem that considers data lifecycle, from production to storage, distribution and utilization of data. First, the target countries were the leading public data countries among the OGP member countries, the USA, the UK, Australia and Canada. The results of this study are as follows. As a result of analyzing the results and comparing Korea’s policies, it was concluded that most of Korea is superior in open government data policy. However, improvement of data quality, development of open data portal as an open platform, support for finding various users including apps and web development companies, and cultivation of open government data utilizing personnel are analyzed as policy issues. In addition, the direction of policy for the balanced ecosystem of Korea is presented together.
4,300원