• Journal of the Korean Society of Systems Engineering
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• v.19 no.1
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• pp.79-90
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• 2023

In principle, R&D of general weapons systems are led by companies or government-funded organizations. In terms of project execution, the defense R&D planning system was reorganized to conduct SE-based project management by integrating the naval ship project execution procedure into the general weapon system R&D procedure. The development progress was confirmed according to the guide for SE application of DAPA, and a technical review meeting was proposed to enter into the each next phase in the R&D process. This paper focuses on improvement for technical review in terms of technical management based on system engineering for R&D mounted weapon systems and the naval surface ship project in preliminary design and detailed design. So, the improvement direction for reviewing the entry criteria for the R&D weapons systems of the naval ship and mounted weapons is proposed.

• Journal of Information Technology Services
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• v.23 no.1
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• pp.27-35
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• 2024

In accordance with the cloud conversion of public sector information systems and the implementation of cloud native introduction policies, review items were presented to review the cloud native of information systems for stable and efficient cloud native deployment. By presenting cloud native considerations when promoting a project, we propose a plan to flexibly respond to policy and business changes and improve development quality and productivity to operate cloud services stably. In order for information project managers to switch to a cloud-native-based information system in order to efficiently utilize the cloud as a cloud, they must decide whether to introduce cloud-native through suitability review questions and sufficiently review development and operation costs and efficiency to promote the project. As a result of conducting a focus group interview (FGI) with a council of cloud native experts, there was an opinion that information systems can be operated in a cloud-native manner even with a monolithic structure. By fully considering the circumstances of each system, development quality and productivity, we expect to be able to operate improved to provide a stable cloud service.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.8-13
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• 2015

One of the most usual indicators to measure the performance of any inventory policy is the mean physical stock. In general, when estimating the mean physical stock in periodic review inventory systems, approximate approaches are often utilized by practitioners and researchers. The mean physical stock is generally calculated by a simple approximation. Still these simple methods are frequently used to analyze various single stockpoint and multi-echelon inventory systems. However, such a simple approximation can be very inaccurate. This is particularly true for low service levels. Even though exact methods to calculate the mean physical stock have been derived, they are available for specific cases only and computationally not very efficient, and therefore less useful in practice. In literature, approximate approaches, such as the simple, the linear, and Simpson approximations, were derived for the periodic review inventory systems that allow backorders. This paper modifies the approximate approaches for the lost sales case and evaluates the modified approximate approaches. Through computational experiments, average (and maximum) percentage deviations of mean physical stock between the exact method and the modified approximations are compared in the periodic review inventory system with lost sales. The same comparison between the modified and the original approximations are also conducted, in order to examine the performance of modified approximations. The results show that all modified approximations perform well for high service levels, but also that the performance may deteriorate fast with decreasing service level. The modified Simpson approximation is clearly better. In addition, the comparison between the modified and the original approximations in the periodic review inventory system with lost sales shows that the modified approximation outperforms the original approximation.

• Korean Circulation Journal
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• v.54 no.8
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• pp.427-453
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• 2024

His bundle pacing (HBP) and left bundle branch pacing (LBBP) are novel methods of pacing directly pacing the cardiac conduction system. HBP while developed more than two decades ago, only recently moved into the clinical mainstream. In contrast to conventional cardiac pacing, conduction system pacing including HBP and LBBP utilizes the native electrical system of the heart to rapidly disseminate the electrical impulse and generate a more synchronous ventricular contraction. Widespread adoption of conduction system pacing has resulted in a wealth of observational data, registries, and some early randomized controlled clinical trials. While much remains to be learned about conduction system pacing and its role in electrophysiology, data available thus far is very promising. In this review of conduction system pacing, the authors review the emergence of conduction system pacing and its contemporary role in patients requiring permanent cardiac pacing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.460-461
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• 2018

The traditional recommendation system is developed on the assumption that users behave independently, and have problem of readability and efficiency are inferior due to simply sort products or lack of function for associate product attributes with user's taste. To solve this problem in this study we propose a system that provides user customized information that the analysis of the unstructured review data with the purchase histories of users processed with meaningful information after crawling product review data using text mining with R. This allows to help user make decisions can be provided only necessary information without analyze massive amounts of products review data.

• Journal of Korean Society of Disaster and Security
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• v.6 no.1
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• pp.87-91
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• 2013

Establish standards and review procedures for on-site implementation of the emergency response plan required to establish by substances requiring preparation for accidents. Investigated for the examination content and standards for Process Safety Management (PSM) and Safety Management System (SMS). Safety Management System operator's comments and problems to be expected in the review process. Standards for on-site implementation and review of a person's ability to do the job does not require a high level of expertise. However, it has been created mainly to determine whether appropriate items to be included in the report and the contents presented.

• Information Systems Review
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• v.23 no.1
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• pp.155-172
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• 2021

With the recent increase in online product purchases, a recommender system that recommends products considering users' preferences has still been studied. The recommender system provides personalized product recommendation services to users. Collaborative Filtering (CF) using user ratings on products is one of the most widely used recommendation algorithms. During CF, the item-based method identifies the user's product by using ratings left on the product purchased by the user and obtains the similarity between the purchased product and the unpurchased product. CF takes a lot of time to calculate the similarity between products. In particular, it takes more time when using text-based big data such as review data of Amazon store. This paper suggests a hybrid recommendation system using a 2-phase methodology and text data mining to calculate the similarity between products easily and quickly. To this end, we collected about 980,000 online consumer ratings and review data from the online commerce store, Amazon Kinder Store. As a result of several experiments, it was confirmed that the suggested hybrid recommendation system reflecting the user's rating and review data has resulted in similar recommendation time, but higher accuracy compared to the CF-based benchmark recommender systems. Therefore, the suggested system is expected to increase the user's satisfaction and increase its sales.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.12
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• pp.1098-1125
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• 2000

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 1998 and 1999 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. 1) A review of the recent studies on fluid flow, turbomachinery and pipe-network shows that many experimental investigations are conducted in applications of impingement jets. Researches on turbulent flows, pipe flows, pipe-networks are focused on analyses of practical systems and prediction of system performance. The results of noise reduction in the turbomachinery are also reported. 2) A review of the recent studies on heat transfer analysis and heat exchanger shows that there were many papers on the channel flow with the application to the design of heat exchanger in the heat transfer analysis. Various experimental and numerical papers on heat exchanger were also published, however, there were few papers available for the analysis of whole system including heat exchanger. 3) A review of the recent studies on heat pump system have focused on the multi-type system and the heat pump cycle to utilize treated sewage as the heat source. The defrosting and the frosting behaviors in the fin-tube heat exchanger is experimentally examined by several authors. Several papers on the ice storage cooling system are presented to show the dynamic simulation program and optimal operation conditions. The study on the micro heat pipes for the cooling of high power electronic components is carried out to examine the characteristics of heat and mass transfer processed. In addition to these, new type of separate thermosyphon is studied experimentally. 4) The recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. New systems operating with natural refrigerants are drawing lots of attention. In addition to these, evaporation and condensation heat transfer characteristics of traditional and new refrigerants are investigated for plain tubes and also for microfin tubes. Capillary tubes and orifice are main topics of research as expansion devices and studies on thermophysical properties of new refrigerants and refrigerant/oil mixtures are widely carried out. 5) A review of the recent studies on absorption cooling system shows that numerous experimental and analytical studies on the improvement of absorber performance have been presented. Dynamic analysis of compressor have been performed to understand its vibration characteristics. However research works on tow-phase flow and heat transfer, which could be encountered in the refrigeration system and various phase-change heat exchanger, were seemed to be insufficient. 6) A review of recent studies on duct system shows that the methods for circuit analysis, and flow balancing have been presented. Researches on ventilation are focused on the measurement of ventilation efficiency, and variation of ventilation efficiency with ventilation methods by numerous experimental and numerical studies. Furthermore, many studies have been conducted in real building in order to estimate indoor thermal environments. Many research works to get some information for cooling tower design have been performed but are insufficient. 7) A review on the recent studies on architectural thermal environment and building mechanical systems design shows that thermal comfort analysis is sitting environment, thermal performance analysis of Korean traditional building structures., and evaluation of building environmental load have been performed. However research works to improve the performance of mechanical system design and construction technology were seemed to be insufficient.

• Journal of Environmental Impact Assessment
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• v.19 no.2
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• pp.179-187
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• 2010

A costal improvement project is designed for preventing disasters on the coast, improving costal environment, and promoting costal functions, so it is different from the one for developing coasts. However, the costal improvement project also affects the surrounding environment and it may damage the costal environment in some cases. In line with this, this study was carried out to provide the guideline to the review on environmental conditions, which should be performed in the stage of establishing the plan for a costal improvement project, so that the influence affecting marine environment can be reduced and more efficient coastal project can be planned. The costal improvement project is different in the degree of affecting the costal environment according to kinds, scales, and regions. Accordingly, in this study the state of the coastal improvement project and involved problems were analyzed. The prior environmental review system was divided into a seawall-installation project, a marine construction such as the installation of submerged breakwater and jetties, and a project for creating water-friendly coast including a park without marine landfill. The main items for reviewing these specific projects were presented.

• Health Policy and Management
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• v.30 no.2
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• pp.164-177
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• 2020

This study aims to compare the experience of selected countries in operating separate payment system for new healthcare technology and to find implications for price setting in Korea. We analyzed the related reports, papers, laws, regulations, and related agencies' online materials from five selected countries including the United States, Japan, Taiwan, Germany, and France. Each country has its own additional payment system for new technologies: transitional pass-through payment and new technology ambulatory payment classification for outpatient care and new technology add-on payment for inpatient care (USA), an extra payment for materials with new functions or new treatment (C1, C2; Japan), an additional payment system for new special treatment materials (Taiwan), a short-term extra funding for new diagnosis and treatment (NUB; Germany), and list of additional payments for new medical devices (France). The technology should be proven safe and effective in order to get approval for an additional payment. The price is determined by considering the actual cost of providing the technology and the cost of existing similar technologies listed in the benefits package. The revision cycle of the additional payment is 1 to 4 years. The cost or usage is monitored during that period and then integrated into the existing fee schedule or removed from the list. We conclude that it is important to set the explicit criteria to select services eligible for additional payment, to collect and analyze data to assess eligibility and to set the payment, to monitor the usage or cost, and to make follow-up measures in price setting for new health technologies in Korea.