The customer of massage chair is expanding day by day from middle age to all ages. In 2018, the market size was 700 billion KRW, an increase of 30 times over 10 years. However, most related SMEs suffer from excessive competition by the market monopoly of some major companies. In this situation, in order for a related company to survive, it is necessary to steadily research and develop new products. Founded in 2009, company L produces massage chairs for health and relaxation of customers. L’s products use a sound wave vibration module that is favorable for human body, unlike other products that use vibration motor type. However, frequent breakdowns of massage chair due to the vulnerability of plate (leaf) springs, which play an important role in sound wave vibration modules, made sap its competitiveness. In this paper, we propose a method to design desirable plate spring structure by sequentially experimenting with five different plate springs. The results of this study are expected to contribute to improve the quality of plate spring and the reliability of sound wave vibration module. In the future, it is necessary to find a way to use it in the development of foot massage or scalp management device as well as continuous research to find optimal plate spring structure through various analysis.
Korea’s R&D investment has significantly increased in recent years and the quantitative outputs such as number of papers and patents have also increased with the investment. However, the quality of R&D outputs has not been fully addressed. In particular, quality of technical performance, such as the quality of patents, has attracted little attention. In this paper, a Data Envelopment Analysis (DEA) method was used to construct models for efficiency analysis of R&D investment, focused on quality of technical performance. Indices were proposed to analyze the quantitative and qualitative efficiencies of R&D investment. In order to effectively analyze R&D efficiencies, the measurement units of the input and output variables were standardized. Based on cases of livestock quarantine R&D projects of Korea, the quantitative and qualitative efficiencies of national R&D projects were analyzed and factors that would influence R&D efficiencies were identified. This paper suggests that both quantitative and qualitative efficiencies should be considered when measuring R&D efficiency. Also, it is recommended to carefully consider the characteristics of R&D projects during project selection stage.
After Dantzig and Rasmer introduced Vehicle Routing Problem in 1959, this field has been studied with numerous approaches so far. Classical Vehicle Routing Problem can be described as a problem of multiple number of homogeneous vehicles sharing a same starting node and having their own routes to meet the needs of demand nodes. After satisfying all the needs, they go back to the starting node. In order to apply the real world problem, this problem had been developed with additional constraints and pick up & delivery model is one of them. To enhance the effectiveness of pick up & delivery, hub became a popular concept, which often helps reducing the overall cost and improving the quality of service. Lots of studies have suggested heuristic methods to realize this problem because it often becomes a NP-hard problem. However, because of this characteristic, there are not many studies solving this problem optimally. If the problem can be solved in polynomial time, optimal solution is the best option. Therefore, this study proposes a new mathematical model to solve this problem optimally, verified by a real world problem. The main improvements of this study compared to real world case are firstly, make drivers visit every nodes once except hub, secondly, make drivers visit every nodes at the right time, and thirdly, make drivers start and end their journey at their own homes.
Automobiles are largely divided into passenger cars with less than five passengers and commercial vehicles such as construction machines, trucks, mixers, special lorries, and large buses. Automobile maintenance companies are also divided into passenger cars and commercial vehicles. Because commercial vehicles are the livelihood vehicles of individual carriers engaged in cargo transportation, passenger transportation, and construction, fast and accurate maintenance is important. Access to the expressway is also important because the car is large and uses highways. In addition, the time required for troubleshooting is long, so sufficient space must be secured for parking the vehicle, and ease of entry and exit of the vehicle in the maintenance shop should be fully considered. For this reason, commercial vehicle maintenance companies have higher initial investment costs than car maintenance companies, and it is difficult to supply and maintain maintenance personnel. Therefore, it is necessary to carefully examine and analyze various related factors for successful commercial vehicle maintenance company selection. However, most existing commercial vehicle maintenance companies often choose their location based on the empirical judgment of the founder, the customs and the case, without a clear analysis. In this study, we show how to derive the location selection factors to be considered when establishing professional maintenance company for commercial vehicles and to select the optimal location by using AHP (Analytic Hierarchy Process) method.
The purpose of this study is to provide the priority of the front-loading factors in the design stage of the automotive parts development process in order to efficiently and effectively respond to the demands of the car maker (customer). Front-loading is defined as a strategy in order to improve development performance by shifting the identification and solving of design problems to earlier phases of a product development process. Two approaches of the front-loading are project-to-project knowledge transfer and rapid problem solving. For the study, a survey was conducted on the R&D department in the automobile parts company and analyzed by AHP (Analytic Hierarchy Process) method. The result of the survey shows the cost savings is the highest weight in terms of front-loading effect and in terms of front-loading factors, it gives priorities as “the problems of past project” first, “Design Review” second, “CAE (Computer Aided Engineering)” third, “FMEA (Failure Mode and Effects Analysis)” fourth, “benchmarking” and SR (Sourcing of Requirements). The results of the study will be helpful to provide practical value for improving product design of component development.
This paper considers the Prisoner’s Dilemma Game in which there exists a dilemma that the best response is that both players are to confess, but doing not confess can give a higher gain to the both players in a social perspective. To resolve such a dilemma in the game, an incentive model to encourage to confess and a penalty model for being imposed when not confessing are introduced, respectively. Then, the conditions are characterized under which incentive or penalty involved in the game’s payoffs can make the game rational without a dilemma on both the personal and social perspectives, by taking the payoff values as variables with the incentive and penalty factors. Furthermore, it turns out that the resulting values of incentive and penalty are inversely proportional to each other, and thus, obtaining one of these amounts can provide the other. Simple examples are shown to interpret the theoretical verifications of our models, and randomly generated data based simulation results investigate the tendency of incentive and penalty and the resulting game values for a variety of instances. These results can provide a framework on resolving the dilemma by artificially putting incentive or penalty, although it is careful to apply more generalized real world games.
Recently the concentration of fine dust and ultra fine dust becomes so bad, which seriously threatens the health and even the life of people. So, government started to investigate several ways to reduce the amount of fine dust and ultra fine dust. From a few years ago it has been known that ships anchored at port emit a lot of pollution and seriously affect air quality of neighboring cities. To reduce the pollution emitted by ship AMP (Alternative Maritime Power Supply) has been proposed, which uses the electricity instead of bunker C oil or diesel. Many developed countries already installed AMP to improve air quality in port area. Korea is in the stage of planning to install AMP at port. However, there are many complicated problems to be handled before AMP installation. Due to huge initial cost and long period of construction ship owner and habour operating company are reluctant to AMP installation. And there are serious technological difficulties in constructing AMP in existing harbour. Lack of AMP core technology and operational difficulties of AMP are also big challenges to be conquered. In this study SWOT/AHP method is used to find strategic and efficient ways to handle above complicated challenges and then to vitalize the AMP installation.
Currently many companies are interested in reduction of the carbon emissions associated with their supply chain activities such as transportation and operations. Operational decisions, such as modifications in order quantities could an effective way in reducing carbon emissions in the supply chain. Cap-and-trade regulation, sometimes called emissions trading, is a market-based tool to limit greenhouse gas emissions. Under cap-and-trade regulation, emission credits are allocated to the firms and the firms trades emissions under cap-and-trade schemes. In this paper, we propose a single-manufacturer single-buyer two-echelon supply chain problem under the cap-and-trade mechanism incorporating the carbon emissions caused by transportation and warehousing activities where a single manufacturer produces a family of items in order to deliver a family of items to a single buyer at a fixed interval of time for effective implementation of Just-In-Time (JIT) Purchasing. An integrated multi-product lot-splitting model of facilitating multiple shipments in small lots between buyer and manufacturer is developed in a JIT Purchasing environment. Also, an iterative heuristic algorithm is developed to derive the common order interval, the number of intervals for each product and the number of shipments between the buyer and the manufacturer during the common interval. A numerical example is given to illustrate the savings in reduction of total cost and carbon emissions by the inventory model incorporating cap-and-trade mechanism compared to the classical inventory model. The proposed inventory model could be useful for the practical solution of two-echelon supply chain inventory problem under cap-and-trade mechanism.
Remotely Piloted Aircraft (RPA) controls as a type of unmanned aerial vehicle (drone) is growing rapidly and its flight controller stick disposition is required standardization. We should standardize RPA drone flight control disposition because the flight pilot of RPA is hard to be trained so the flight controller stick differences impairs safety and wastes time and effort of flight controller industry. So this study researches the on-going standardization of RPA drone flight control disposition in Korea and foreign countries. Also this paper analyzes and researches of expert about RPA drone flight controller function and application of flight control mode. I accomplished expert research about standardization plan of unmanned flight control mode and confirm the necessity. Nowadays mode1 and 2 are mostly used in Korea so I carried out preference investigation for two modes. There were 4 preferences choices of RPA drone control mode necessity (importance) and recommendation of standardization modes. They answered that necessity of standardization is important considering pilot training, flight safety and positive development of drone industry. The result of standardization mode preference is that they prefer mode 2 (drone maker 86%, training facilities and research facilities 58%, government bureau 60%). Overall preference result shows that mode 1 24%, mode 1&2 16%, mode 2 60%. So they preferred mode 2 by 60%. The differences between two modes are the direction of throttle and pitch. Direction of throttle and pitch operate opposite way. They prefer mode 2 because mode 2 has similarities of manned flight control mode. Significance of this study is that it showed the necessity of standardization and flight control preference in a quantitative way. It will help drone standardization in related industries and development direction near future.
The South Korean government is actively assisting the supply of the smart factory solutions to SMEs (Small & Medium-sized Enterprises) according to its manufacturing innovation 3.0 policy for the smart manufacturing as the 4th industrial revolution era unfolds. This study analyzed the impacts of the smart factory solutions, which have been supplied by the government, on the companies performances. The effects of the level of smart factory and the operation capabilities for the smart factory solutions on company performances, and the mediating effects of manufacturing capabilities have been analyzed using SPSS and AMOS. The data for this survey-based study were collected from the SMEs which implemented the smart factory solutions since 2015. The results show that the level of smart factory solutions adopted and operation capabilities for the smart factories do not have direct effects on the company performances, but their mediating effects on the manufacturing capabilities matter and the manufacturing capabilities effect directly on the company performances. In addition significant factors boosting the operation capability for the smart factory and the levels of the smart factory solutions are identified. Finally, the policy direction for enhancing the smart factory effects is presented, and the future research directions along with the limitations are suggested.
Lately, there have been tremendous shifts in the business technology landscape. Advances in cloud technology and mobile applications have enabled businesses and IT users to interact in entirely new ways. One of the most rapidly growing technologies in this sphere is business intelligence, and associated concepts such as big data and data mining. BI is the collection of systems and products that have been implemented in various business practices, but not the information derived from the systems and products. On the other hand, big data has come to mean various things to different people. When comparing big data vs business intelligence, some people use the term big data when referring to the size of data, while others use the term in reference to specific approaches to analytics. As the volume of data grows, businesses will also ask more questions to better understand the data analytics process. As a result, the analysis team will have to keep up with the rising demands on the infrastructure that supports analytics applications brought by these additional requirements. It’s also a good way to ascertain if we have built a valuable analysis system. Thus, Business Intelligence and Big Data technology can be adapted to the business’ changing requirements, if they prove to be highly valuable to business environment.
Discrete-time Queueing models are frequently utilized to analyze the performance of computing and communication systems. The length of busy period is one of important performance measures for such systems. In this paper, we consider the busy period of the Geo/Geo/1/K queue with a single vacation. We derive the moments of the length of the busy (idle) period, the number of customers who arrive and enter the system during the busy (idle) period and the number of customers who arrive but are lost due to no vacancies in the system for both early arrival system (EAS) and late arrival system (LAS). In order to do this, recursive equations for the joint probability generating function of the busy period of the Geo/Geo/1/K queue starting with n, 1≤n≤K, customers, the number of customers who arrive and enter the system, and arrive but are lost during that busy period are constructed. Using the result of the busy period analysis, we also numerically study differences of various performance measures between EAS and LAS. This numerical study shows that the performance gap between EAS and LAS increases as the system capacity K decrease, and the arrival rate (probability) approaches the service rate (probability). This performance gap also decreases as the vacation rate (probability) decrease, but it does not shrink to zero.
A sharing economy has emerged through today’s trust-building mechanisms, and a sharing economy is called a future economic model through a positive future market prospect. In this context, while the overseas sharing economic business is becoming a global trend, the domestic sharing economic business is busy following the global trend. The purpose of this study is to investigate the development direction of sharing economic business in Korea. First, the sharing economic cases of 50 oversea and domestic businesses were analyzed by time series analysis. Next, a cross-country analysis to analyze the business distribution and KCERN's sharing economic model through sharing economic cube model was conducted. Finally, profit model analysis through business case study and the relationship between the derived factors were investigated. As a result of the analysis, this study found comparative trends between overseas and domestic including differences in cultural and institutional environments and profit models. This study suggested directions for domestic sharing economy business.
The Dynamic Vehicle Routing Problem (DVRP) involves a combinatorial optimization problem where new customer demands become known over time, and old routes must be reconfigured to generate new routes while executing the current solution. We consider the high level of dynamism problem. An application of highly dynamic DVRP is the ambulance service where a patient contacts the service center, followed by an evaluation of case severity, and a visit by a practitioner/ ambulance is scheduled accordingly. This paper considers a variant of the DVRP and proposes a decentralized algorithm in which collaborators (Depot and Vehicle), both have only partial information about the entire system. The DVRP is modeled as a periodic re optimization of VRP using the proposed decentralized algorithm where collaborators exchange local information to achieve the best global objective for the current state of the system. We assume the existence of a dispatcher e.g., headquarter of the company who can communicate to vehicles in order to gather information and assigns the new visits to them. The effectiveness of the proposed decentralized coordination algorithm is further evaluated using benchmark data given in literature. The results show that the proposed method performed better than the compared algorithms which utilize the centralized coordination in 12 out of 21 benchmark problems.
Nowadays, since there are so many big data available everywhere, those big data can be used to find useful information to improve design and operation by using various analysis methods such as data mining. Especially if we have event log data that has execution history data of an organization such as case_id, event_time, event (activity), performer, etc., then we can apply process mining to discover the main process model in the organization. Once we can find the main process from process mining, we can utilize it to improve current working environment. In this paper we developed a new method to find a final diagnosis of a patient, who needs several procedures (medical test and examination) to diagnose disease of the patient by using process mining approach. Some patients can be diagnosed by only one procedure, but there are certainly some patients who are very difficult to diagnose and need to take several procedures to find exact disease name. We used 2 million procedure log data and there are 397 thousands patients who took 2 and more procedures to find a final disease. These multi-procedure patients are not frequent case, but it is very critical to prevent wrong diagnosis. From those multi-procedure taken patients, 4 procedures were discovered to be a main process model in the hospital. Using this main process model, we can understand the sequence of procedures in the hospital and furthermore the relationship between diagnosis and corresponding procedures.
In this study, BSC model of center for teaching and learning was developed using balanced scorecard suitable for non-profit organization. Firstly, relevant literature surveys and evaluation indicators of various CTL and institution with similar characteristics were examined. Next, a draft BSC model was designed through interviews of specialists. Lastly, the BSC model was proposed by verifying the content validity of the evaluation model by conducting two Delphi surveys. The BSC model of CTL has 4 perspectives: resource, customer, internal process, learning and growth, 9 critical success factors: 2 factors in resource, customer and learning and growth perspectives, 3 factors in internal process perspective, and 23 key performance Indicators: 4 indicators in resource and learning and growth, 7 indicators in customer perspective, 8 indicators in internal process perspective. The implications of this study through the results were as follows: firstly, the proposed BSC model showed an evaluation model suitable for a non-profit organization. Second, the BSC model was linked to the organization’s mission and vision. Third, it could contribute to the long-term development of CTL. Lastly, if it could be applied to management, and evaluated, it is expected to play a role of providing basic data for the budget support and spread of the university.
All machines deteriorate in performance over time. The phenomenon that causes such performance degradation is called deterioration. Due to the deterioration, the process mean of the machine shifts, process variance increases due to the expansion of separate interval, and the failure rate of the machine increases. The maintenance model is a matter of determining the timing of preventive maintenance that minimizes the total cost per wear between the relation to the increasing production cost and the decreasing maintenance cost. The essential requirement of this model is that the preventive maintenance cost is less than the failure maintenance cost. In the process mean shift model, determining the resetting timing due to increasing production costs is the same as the maintenance model. In determining the timing of machine adjustments, there are two differences between the models. First, the process mean shift model excludes failure from the model. This model is limited to the period during the operation of the machine. Second, in the maintenance model, the production cost is set as a general function of the operating time. But in the process mean shift model, the production cost is set as a probability functions associated with the product. In the production system, the maintenance cost of the equipment and the production cost due to the non-confirming items and the quality loss cost are always occurring simultaneously. So it is reasonable that the failure and process mean shift should be dealt with at the same time in determining the maintenance time. This study proposes a model that integrates both of them. In order to reflect the actual production system more accurately, this integrated model includes the items of process variance function and the loss function according to wear level.
Since the appearance of smartphones, the smartphone market has been in fierce completion by new technologies and marketing trends. The smartphone market is now somewhat saturated, and the manufacturers are trying to improve their position in the market through the repurchase of existing customers and the influx of competitors. At the same time, customers have their own purchasing criteria for smartphones. Therefore, manufacturers need to determine new technology and marketing trends based on customer purchasing trends and usage characteristics. The aim of this study is to analyze the quality attributes of smartphones. We conducted a survey on 220 respondents, and divided the respondents into several groups by purchasing trends and usage characteristic through cluster analysis. The groups are analyzed and compared based on the Kano model for the quality attributes of smartphone. The analysis result are as follows. Firstly, purchasing trends divide responders into groups that prefers high-end premium smartphones and those that take into account practicality in terms of purchasing trends. Secondly, usage characteristic divide responders into three groups: those with clear usage pattern, those who prefer ease of use, and the rest, and we find out that those with clear usage pattern are important customer in viral marketing. Lastly, Kano analysis is revealed the ‘Slow/ hi-speed camera’, ‘Private mode’, ‘Widget’, ‘Health care’ are attractive quality attributes.
Innovation activities represented by Six Sigma (6σ) led to improvements not only in manufacturing industries but also in various business fields. In the aviation industry, Six Sigma has been used as a tool of innovation since the beginning of 2000, and it has developed into a comprehensive form of innovation activity that includes various improvement tools. In this study, the innovation activities in K company that is a representative company of aviation industry are summarized in the last 10 years, and the effectiveness of the innovation tools and the performance of the tasks are also analyzed. The results of 2,091 projects over the past decade have been analyzed from various perspectives. First, we found out the tools that were used frequently at each DMAIC step, showed their frequency, and analyzed the evaluation results for the project. The project was evaluated from grade 1 (highest level) to grade 7 (lowest level) with an average grade of 4.1 for the overall project. The evaluation grades of the projects were compared and analyzed in terms of the qualifications of the leader, the roadmap for the implementation of the project, the financial effect, the size of the financial effect, the business classification, and the project execution period. These results may suggest new perspectives for companies considering or adopting innovation programs.
This study attempts to improve the understanding of the rapidly growing online video platform market such as Youtube and OTT, and to investigate the attributes and relative importance of them. For this purpose, the factors that influence the choice to use were derived through literature studies and the Focus Group Interview (FGI), and the priority of the factors was calculated through the analytic hierarchy process (AHP). The upper layer of the AHP structure was ‘Relationship’, ‘Entertainment’, ‘Informativity’, and ‘Convenience’, and the lower layer was structured into 13 elements. The importance priority analysis among the factors that influence the choice to use was done by teenagers, 20s, and 30s and the results are summarized as follows : First, Users consider the ‘Just for fun’ and ‘Satisfaction of interests’ as the most important factors, followed by ‘Easy accessibility to use’, ‘Vicarious satisfaction’, ‘Usefulness of Information’, and ‘Up-to-dateness of information’. Second, the ranking of the upper layer was in the order of ‘Entertainment’-‘Informativity’-‘Convenience’-‘Relationship’.As a result of AHP,‘Entertainment’ was 3.6 times more important than ‘Relationship’. In the comparison by age group, only teenagers regarded that ‘Convenience’ is more important than ‘Informativity’. According to the characteristics of the age group, the lower layer of teenagers consider ‘Convenient function’ to be important and ranked ‘Usefulness of information’ in 8th. While ‘Vicarious satisfaction’ ranked 4th out of 13 factors in the entire age group, those in their 20s and 30s ranked 8th, showing a difference. In the case of 20s, ‘Reasonable price’ was ranked 4th and the ‘Diversity of Information’ was ranked 5th, Otherwise 30s consider ‘Trustworthiness of Information’ to the third. Third, unlike ‘Convenience’ which was the lower-rank in the upper layer AHP analysis, ‘Easy accessibility to use’, the lower-layer of convenience, ranked third overall in the importance analysis among the 13 lower-layer factors, and showed a similar patterns in the age groups results. In the conclusion, this study demonstrates that ‘Convenience’ and ‘Vicarious satisfaction’ factors, which were not relatively well addressed in the previous studies, are the key factors to be considered in. By presenting the results of the importance analysis on each of the selected attributes, This study has a practical implication that Industries such as on-line video service platform provider can use the importance priority in establishing the directions of future strategy.