• Title/Summary/Keyword: Life-cycle cost

Search Result 1,051, Processing Time 0.028 seconds

A Study on Fuel Selection for Next-Generation Launch Vehicles (차세대 발사체용 연료선정에 관한 연구)

  • Kim, Cheulwoong;Lim, Byoungjik;Lee, Keejoo;Park, Jaesung
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.25 no.3
    • /
    • pp.62-80
    • /
    • 2021
  • The requirements for the next-generation propulsion system and for a good propellant have been summarized. The characteristics and effectiveness of kerosene, hydrogen, and methane, which are the fuels that are mainly attracting attention in Korea and abroad, were compared with each other. As a result of the comparison, methane was evaluated to be more advantageous than other fuels in reliability, cost, reusability, maintenance, eco-friendliness, safety, lifespan, technical difficulties, engine cycle selection, application of common bulkhead, and non-disassembly/reassembly delivery. And in terms of performance, the specific impulse of methane is higher than that of kerosene, so the efficiency of the launch vehicle can be increased. Methane's properties incluidng eco-friendliness, low-temperature combustion, long life, and maintenability make it beneficial for reuse and for the development of multi-purpose engines.

A Study on the Newly Recognized Defect Factors in Defect Lawsuits of Apartment Housing (공동주택 하자소송단계에서의 하자인정항목에 관한 연구)

  • Ko, Young-Tae;Shin, Yoon-Seok;Lee, Myungdo
    • Journal of the Korea Institute of Building Construction
    • /
    • v.20 no.6
    • /
    • pp.567-576
    • /
    • 2020
  • This study proposes additional items to be recognized as defects in a defect lawsuit through a case analysis of lawsuit cases in apartment housing. Identifying these defects prevents an unexpected increase in litigation costs, delays in the date of litigation, and emotion repercussions or additional lawsuits. In this study, the defects that were not discovered by the existing occupants and construction companies, but were newly discovered in litigation, were defined as defects in lawsuits. Fifteen cases of lawsuits were analyzed and a total of 77 defects were derived. Each item was then reviewed for location, work type, number of occurrences, and cost. The results were yielded 23 defect items, which were validated by appraisers who directly appraised the cases. In addition, the derived defect factors were analyzed. Finally, the 23 defect items were categorized into 10 main factors which include attributes such as causes of occurrence and characteristics. This can provide an overall area of defects to be considered in addition to existing defect items in the life cycle of the housing. The results of this study can contribute to reducing the actual occurrence of defects and minimizing the disputes in the case of defect lawsuits.

Plug-and-Play Framework for Connectivity Control and Self-Reconfiguration of Weapon System Components (무기체계 구성장치의 연결성 제어 및 자율 재구성을 위한 플러그앤플레이 프레임워크)

  • Chang, HyeMin;Kang, SukJong;Cho, YoungGeol;Yoon, JooHong;Yun, Jihyeok
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.24 no.3
    • /
    • pp.328-338
    • /
    • 2021
  • A study on common modular design based on open standards to reduce the life cycle cost of ground weapon system is underway. Since the ground weapon system includes major mission equipment such as fire control system, it is essential to apply the concept of fault tolerance through automatic reconfiguration and blocking unspecified equipment through connectivity control. However, it is difficult to generalize due to the difference in operating characteristics for each system. In this paper, we propose a plug-and-play framework, which includes plug-and-play architecture and mechanism. The proposed method can be used in common by the application of each component as it is divided into a common service layer. In addition, the proposed connectivity control and autonomous reconfiguration method facilitates reflection of operating characteristics for each system. We constructed a verification environment that can simulate ground weapon systems and components, and verified that the proposed framework works through scenario-based functional tests.

Case Study on Advanced Fire and Explosion Index (화재폭발지수 개선에 대한 사례 연구)

  • Na, Gun Moon;Seoe, Jae Min;Lee, Mi Jeong;Baek, Jong-Bae
    • Journal of the Korean Society of Safety
    • /
    • v.35 no.6
    • /
    • pp.78-84
    • /
    • 2020
  • The F&EI technique is one of the risk assessments with many advantages. It can save time and effort compared to quantitative risk assessment (QRA). By using the evaluation result of this technique, it is possible to check the effectiveness of the investment cost. In addition, a relative risk ranking can be created and used to establish the facility management cycle and to prioritize investment. However, evaluating the target process can be evaluated more than the actual risk since the LCCF, a loss prevention measure, is too limited. In addition, calculating premiums via this method can result in excessive premiums, making it difficult to evaluate the risk precisely. Therefore, new safety guard was added to the LCCF of the F&EI risk assessment with reference to HAZOP and LOPA techniques. Newly added LCCFs are Deflagration arrester, Check valve, SIS, and Vacuum beaker, etc. As a case study, F&EI risk assessment was performed on Acetone storage tank of a API (Active pharmaceutical ingredient) plant to compare actual MPPD. The estimated loss amount was 592,558$ for the existing technique and 563,571$ for the improved technique, which was reduced by about 5% compared to the previous one.This proved that a more precise evaluation is possible and that the efforts for safety at the workplace are reflected in the evaluation results.

The Improvement of NDF(No Defect Found) on Mobile Device Using Datamining (데이터 마이닝 기법을 활용한 Mobile Device NDF(No Defect Found) 개선)

  • Lee, Jewang;Han, Chang Hee
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.44 no.1
    • /
    • pp.60-70
    • /
    • 2021
  • Recently, with the development of technologies for the fourth industrial revolution, convergence and complex technology are being applied to aircraft, electronic home appliances and mobile devices, and the number of parts used is increasing. Increasing the number of parts and the application of convergence technologies such as HW (hardware) and SW (software) are increasing the No Defect Found (NDF) phenomenon in which the defect is not reproduced or the cause of the defect cannot be identified in the subsequent investigation systems after the discovery of the defect in the product. The NDF phenomenon is a major problem when dealing with complex technical systems, and its consequences may be manifested in decreased safety and dependability and increased life cycle costs. Until now, NDF-related prior studies have been mainly focused on the NDF cost estimation, the cause and impact analysis of NDF in qualitative terms. And there have been no specific methodologies or examples of a working-level perspective to reduce NDF. The purpose of this study is to present a practical methodology for reducing NDF phenomena through data mining methods using quantitative data accumulated in the enterprise. In this study, we performed a cluster analysis using market defects and design-related variables of mobile devices. And then, by analyzing the characteristics of groups with high NDF ratios, we presented improvement directions in terms of design and after service policies. This is significant in solving NDF problems from a practical perspective in the company.

A Process of Optimization for the Best Orientation of Building Façades Based on the Genetic Algorithm by Utilizing Digital Topographic Map Data (수치지형도 데이터를 활용한 유전자 알고리즘 기반 건축외피의 최적향 산정 프로세스)

  • Choe, Seung-Ju;Han, Seung-Hoon
    • Land and Housing Review
    • /
    • v.13 no.1
    • /
    • pp.113-129
    • /
    • 2022
  • A building's eco-friendliness is directly related to various values including the life cycle cost of a building. However, the conventional architectural design method has a limitation in that it cannot create an optimized case according to the surrounding environmental conditions. Therefore, the purpose of this research is to present a design assistance tool that can review planning cases optimized for the environmental conditions of the building site in the planning stage of architectural production. To achieve the purpose of the study, an algorithm for realizing 3D modeling of the region and analysis of the solar environment was produced based on the site contours, building, and road information from the digital topographic map provided by the National Geographic Information Institute. To examine the validity of the developed algorithm, a comparative experiment was conducted targeting the elevation direction of the existing building. As a result, it was found that the optimal elevation direction selected by the algorithm can receive higher insolation compared to the front facade of the main building.

A Basic Study on the Determination Method of Reconstruction and Remodeling of Deteriorated School Facilities - Focusing on the Case of S High School in Incheon Metropolitan City - (노후 학교시설의 개축 및 리모델링 타당성 판별 방법에 대한 기초연구 -인천광역시 S 고등학교 사례를 중심으로-)

  • Meang, Joon-Ho;Kim, Sung-Joong;Song, Byung-Joon;Kim, Jae-Young
    • The Journal of Sustainable Design and Educational Environment Research
    • /
    • v.21 no.2
    • /
    • pp.1-10
    • /
    • 2022
  • This study aims to prepare an objective project basis by reviewing the feasibility of reconstructing and remodeling Greensmart Future School project for S High School's main building, which was built more than 40 years ago, in Incheon Metropolitan City, and to apply and review an effective methodology for determining renovation and remodeling. To this end, the feasibility of reconstruction and remodeling was evaluated in the long term by synthesizing the results of quantitative evaluation through economic review and qualitative evaluation through educational functional review. As a result of the study, it was found that the reconstruction plan was advantageous throughout all alternatives in terms of economic costs, and the field survey indicated limitations in spatial functions to support students' various educational activities and applying new directions, especially the 2022 revised curriculum and high school credit system.

Considerations for Applying Korean Natural Language Processing Technology in Records Management (기록관리 분야에서 한국어 자연어 처리 기술을 적용하기 위한 고려사항)

  • Haklae, Kim
    • Journal of Korean Society of Archives and Records Management
    • /
    • v.22 no.4
    • /
    • pp.129-149
    • /
    • 2022
  • Records have temporal characteristics, including the past and present; linguistic characteristics not limited to a specific language; and various types categorized in a complex way. Processing records such as text, video, and audio in the life cycle of records' creation, preservation, and utilization entails exhaustive effort and cost. Primary natural language processing (NLP) technologies, such as machine translation, document summarization, named-entity recognition, and image recognition, can be widely applied to electronic records and analog digitization. In particular, Korean deep learning-based NLP technologies effectively recognize various record types and generate record management metadata. This paper provides an overview of Korean NLP technologies and discusses considerations for applying NLP technology in records management. The process of using NLP technologies, such as machine translation and optical character recognition for digital conversion of records, is introduced as an example implemented in the Python environment. In contrast, a plan to improve environmental factors and record digitization guidelines for applying NLP technology in the records management field is proposed for utilizing NLP technology.

Implementation of Git's Commit Message Complex Classification Model for Software Maintenance

  • Choi, Ji-Hoon;Kim, Joon-Yong;Park, Seong-Hyun
    • Journal of the Korea Society of Computer and Information
    • /
    • v.27 no.11
    • /
    • pp.131-138
    • /
    • 2022
  • Git's commit message is closely related to the project life cycle, and by this characteristic, it can greatly contribute to cost reduction and improvement of work efficiency by identifying risk factors and project status of project operation activities. Among these related fields, there are many studies that classify commit messages as types of software maintenance, and the maximum accuracy among the studies is 87%. In this paper, the purpose of using a solution using the commit classification model is to design and implement a complex classification model that combines several models to increase the accuracy of the previously published models and increase the reliability of the model. In this paper, a dataset was constructed by extracting automated labeling and source changes and trained using the DistillBERT model. As a result of verification, reliability was secured by obtaining an F1 score of 95%, which is 8% higher than the maximum of 87% reported in previous studies. Using the results of this study, it is expected that the reliability of the model will be increased and it will be possible to apply it to solutions such as software and project management.

Research Trends of Technology Holding Companies and Suggestions for improving Corporate Performance : Focusing on the introduction of PMO (기술지주회사 연구동향과 기업성과 향상을 위한 제언 : Project Management Office(PMO) 도입을 중심으로)

  • Lee, Kangoh;Lee, Chanho
    • Journal of East Asia Management
    • /
    • v.4 no.1
    • /
    • pp.53-77
    • /
    • 2023
  • Modern company faces an uncertain future and a competitive environment and are seeking new technologies and creative products to ensure the corporate growth and survival in the market through continuous innovation. "University Industry Cooperation(UIC)" is a point of contact for overcoming the crisis faced by companies and universities in this era and a cooperation platform for mutual prosperity. As a subsidiary of a university, "Technology Holding Company(THC)" is attracting attention as a new window for UIC in Korea. The role of THC is to establish and foster the business opportunities of their subsidiaries and to return investment profits to the university ecosystem again. But recently, the life cycle of technology is getting shorter, and the development cost is steadily increasing. In particular, with the increase of hybrid projects based on convergence and combination, the risk of conducting research(R&D) and new product development(NPD) projects is gradually increasing. A PMO refers to a project management organization that can contribute to improving the success rate of projects with increasing uncertainty by supporting project visibility and appropriate decision-making. The purpose of this study is to raise a research question on whether THC's corporate performance can be improved when "Project Management System(PMO Service)" is introduced into the subsidiary incubation system of THC. This study proposes several research methods to identify the relationship between the introduction of PMO and the corporate performance of THC.