• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.143-150
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• 2019

We focus on the weapon target assignment and fire scheduling problem (WTAFSP) with the objective of minimizing the makespan, i.e., the latest completion time of a given set of firing operations. In this study, we assume that there are m available weapons to fire at n targets (> m). The artillery attack operation consists of two steps of sequential procedure : assignment of weapons to the targets; and scheduling firing operations against the targets that are assigned to each weapon. This problem is a combination of weapon target assignment problem (WTAP) and fire scheduling problem (FSP). To solve this problem, we define the problem with a mixed integer programming model. Then, we develop exact algorithms based on a dynamic programming technique. Also, we suggest how to find lower bounds and upper bounds to a given problem. To evaluate the performance of developed exact algorithms, computational experiments are performed on randomly generated problems. From the results, we can see suggested exact algorithm solves problems of a medium size within a reasonable amount of computation time. Also, the results show that the computation time required for suggested exact algorithm can be seen to increase rapidly as the problem size grows. We report the result with analysis and give directions for future research for this study. This study is meaningful in that it suggests an exact algorithm for a more realistic problem than existing researches. Also, this study can provide a basis for developing algorithms that can solve larger size problems.

• Korean Journal of Materials Research
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• v.29 no.7
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• pp.443-450
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• 2019

Thermal management is a critical issue for the development of high-performance electronic devices. In this paper, thermal conductivity values of mild steel and stainless steel(STS) are measured by light flash analysis(LFA) and dynamic thermal interface material(DynTIM) Tester. The shapes of samples for thermal property measurement are disc type with a diameter of 12.6 mm. For samples with different thickness, the thermal diffusivity and thermal conductivity are measured by LFA. For identical samples, the thermal resistance($R_{th}$) and thermal conductivity are measured using a DynTIM Tester. The thermal conductivity of samples with different thicknesses, measured by LFA, show similar values in a range of 5 %. However, the thermal conductivity of samples measured by DynTIM Tester show widely scattered values according to the application of thermal grease. When we use the thermal grease to remove air gaps, the thermal conductivity of samples measured by DynTIM Tester is larger than that measured by LFA. But, when we did not use thermal grease, the thermal conductivity of samples measured by DynTIM Tester is smaller than that measured by LFA. For the DynTIM Tester results, we also find that the slope of the graph of thermal resistance vs. thickness is affected by the usage of thermal grease. From this, we are able to conclude that the wide scattering of thermal conductivity for samples measured with the DynTIM Tester is caused by the change of slope in the graph of thermal resistance-thickness.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.11
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• pp.1531-1537
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• 2018

In maritime logistics, a large number of containers are transported to the destination through a port in the form of composite transportation such as ships, trucks, and railways. Logistics parties such as shipping companies and consignors prefer having the real-time information on the entry and exit of the logistics hubs of the freight. Particularly, a port is an important space that connects the maritime and inland areas. Hence, the interest about freight of the logistics party in port is high. This study describes tracking the location of freight by using GPS dynamically based on area type rather than point type. This presents dynamic information of location tracking when the freight enters, exits from, and passes through a certain port area. I suggest a real-time location of the container cargos tracking algorithm in port-entry, port-exit, and port inside using Active IP-RFID technology based on the location tracking algorithm of previous research.

• KNOM Review
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• v.21 no.2
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• pp.35-45
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• 2018

As Network Slicing functionality gets applied to mobile networking, a mechanism that enables the selection of network slices becomes indispensable. Following the 3GPP Technical Specification for the 5G Architecture, the inclusion of the Network Slice Selection Function (NSSF) in order to leverage the process of slice selection is apparent. However, actual implementation of this network function needs to deal with the dynamic changes of network instances, due to this, a platform that supports the orchestration of Virtual Network Functions (VNF) is required. Our proposed solution include the use of the Central Office Rearchitected as a Data Center (CORD) platform, with the specified profile for mobile networks (M-CORD) that integrates a service orchestrator (XOS) alongside solutions oriented to Software Defined Networking (SDN), Network Function Virtualization (VNF) and virtual machine management through OpenStack, in order to provide the right ecosystem where our implementation of NSSF can obtain slice information dynamically by relying on synchronization between back-end services and network function instances.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.441-453
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• 2019

Organic farming is considered an effective form of sustainable agricultural management. However, understanding of soil microbial diversity and composition under long-term organic and conventional farming is still limited and controversial. In this study, the Illumina MiSeq platform was applied to investigate the responses of soil bacterial and fungal diversity and compositions to organic farming (OF) and improved conventional farming (CF, applied straw retention) in the rice-wheat rotation system. The results highlighted that the alpha diversity of microbial communities did not differ significantly, except for higher bacterial diversity under OF. However, there were significant differences in the compositions of the soil bacterial and fungal communities between organic and conventional farming. Under our experimental conditions, through the ecological functional analysis of significant different or unique bacterial and fungal taxonomic members at the phyla and genus level, OF enhanced nitrogen, sulfur, phosphorus and carbon dynamic cycling in soil with the presence of Nodosilinea, Nitrospira, LCP-6, HB118, Lyngbya, GOUTA19, Mesorhizobium, Sandaracinobacter, Syntrophobacter and Sphingosinicella, and has the potential to strengthen soil metabolic ability with Novosphingobium. On the other hand, CF increased the intensity of nitrogen cycling with Ardenscatena, KD1-23, Iamia, Nitrosovibrio and Devosia, but enriched several pathogen fungal members, including Coniochaeta, Corallomycetella, Cyclaneusma, Cystostereum, Fistulina, Curvularia and Dissoconium.

• Journal of Industrial Convergence
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• v.16 no.2
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• pp.1-14
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• 2018

The interconnectedness of all things is continuously expanding. For example, bluetooth low energy (BLE) beacons are wireless radio transmitters that can send an identifier to nearby receivers and trigger a number of applications, from proximity marketing to indoor location-based service. iBeacon technology which is one of the newest technologies in the smart tourism field, is reckoned as being very useful for travelers in enhancing the experience with visiting places. However, there is consequently not much existing research yet about the connection between iBeacon technology and tourism destination. Considering that, this study analyzes the adoption of iBeacon in tourism destination, this study examine the interrelationships and feedback structures of key factors in iBeacon adoption. To serve the purpose, this study used system dynamics approach to develop a model of iBeacon adoption in tourism destination. The analysis results showed that the concept of 'Social Influences' is one of the significant predictors for individual's intention behavior to accept iBeacon, and word of mouth (WOM), subjective norm, privacy concern, and perceived usefulness are key factors influencing the iBeacon adoption.

• Journal of Industrial Convergence
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• v.16 no.1
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• pp.1-14
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• 2018

Online retail business has provided internet-based companies with the opportunities to be connected with online customers from all over the world. However, many online customers do not complete their transactions online even if they have already choose what they want because they perceive online payment service is risky or perceive difficulty of paying online. A large body of researchers have examined the important variables that influence online payment, however, these studies can hardly predict the future development tendency after five or ten years since the environment of online market changes so fast more than ever. Therefore, the purpose of this study is to examine the importance of factors affecting online payment and to provide long term dynamic decision making model for third-party payment companies and online service providers. To serve the purpose, this study used system dynamics approach to develop a model of online payment adoption and to simulate various development paths for ten years. The analysis results show that the number of online payment customers increase continuously in ten years, and service quality, system quality, and effort expectancy are key factors for customers to pay online.

• Korean Journal of Community Nutrition
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• v.26 no.5
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• pp.363-381
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• 2021

Objectives: This study examined the Korean elderly's dietary intake status, subjective health-related perception and chronic disease prevalence among age groups. Associations of dietary quality with subjective health-related perception and chronic diseases were also examined. Methods: Based on data from the 7th National Health and Nutrition Examination Survey, a total of 3,231 elderly were selected and categorized into 4 age groups of '65 ~ 69', '70 ~ 74', '75 ~ 79' and 'over 80'. Nutrient intakes, proportions of those with insufficient nutrient intakes, Korean Healthy Eating Index (KHEI), some subjective health-related perceptions and prevalence of major chronic diseases were compared according to the age groups. Differences in the subjective health-related perceptions and odds ratios of the chronic diseases according to the quartile levels of KHEI within the same age group were analyzed. Results: With the increase of age, several nutrient intakes (P < 0.001) and KHEI scores significantly decreased (P < 0.01). In women, activity restriction increased (P < 0.05), and EQ-5D score decreased with age (P < 0.001). Prevalence of hypertension (P < 0.0001), hypercholesterolemia (P < 0.05) and anemia (P < 0.01) significantly increased, while hypertriglyceridemia (P < 0.01) significantly decreased only in men. Obesity prevalence decreased, while underweight prevalence increased (P < 0.05). Subjective health status, EQ-5D score and PHQ-9 score significantly improved as KHEI score increased in certain age groups of women (P < 0.05). Odds ratio of hypercholesterolemia significantly increased with the increase of KHEI score in 65 ~ 69-year-old women. However, hypertension and anemia significantly decreased with the increase of KHEI score in 75 ~ 79-year-old women (P < 0.05). Conclusions: The study findings suggest that nutrition management and policy for the Korean elderly need to apply a segmented age standard that can better reflect their dynamic characteristics.

• Journal of Digital Convergence
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• v.19 no.1
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• pp.67-75
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• 2021

Despite the increase in sales of imported vehicles in Korea, research on the sales forecast of parts logistics centers is very limited. This study aims to perform a sales prediction on bestselling goods in the automobile part logistics center. System dynamics was adopted as a methodology for the prediction method, which considered causal relationship of variables that affected the dynamic characteristics and feedback loops. The analysis results showed that the consumable sales amount of oil increased over time. As a result of conducting the MAPE, the model was assessed to be a reasonable predictive model of 31.3%. In addition, the sales of battery products increased from every October in both of actual and predicted data followed by the peak sales in December and then decrease from next February. This study has academic implications that it secured actual data of specific imported automobile part logistics center, which has not done before in previous studies and quantitatively analyzed the prediction of the quantity of released goods of future sales through system dynamics.

• Korean Journal of Clinical Pharmacy
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• v.30 no.4
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• pp.226-233
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• 2020

Background: Currently, the over-the-counter (OTC) drug market is flooded with series OTC products. The pharmacist must follow the OTC product's indication, given that the most critical role of a pharmacist is the right selection and recommendation of an OTC drug for a patient's symptoms in a dynamic pharmacy environment. Therefore, pharmacists must know each OTC product information precisely to avoid any ambiguity due to several OTC series brand names. Objective: We evaluated the risk and effectiveness of OTC series medicines. Methods: From December 5 to December 18, 2019, an online survey was conducted among 145 community pharmacists. Results: A total of 51.0% of pharmacists knew the difference between products named in a series and could explain it spontaneously. Only 0.7% of the pharmacists admitted to not knowing the difference between products named in a series. While 42.9% of pharmacists who owned a pharmacy opined that the OTC medicines named in a series have health benefits for patients, 50.0% of employee pharmacists admitted that they were rather confused because there are several OTC series medicines. In contrast, 69.2% of pharmacists who owned pharmacies and 72.2% of employee pharmacists admitted that OTC series drugs with names similar to popular OTC drugs sell better. Conclusion: While pharmacists had different opinions regarding OTC series drugs per employment status, they opined that OTC series are more helpful in pharmacy management than completely new brand names. Further studies in this regard are needed.