• Title/Summary/Keyword: Energy audit

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Flux Regulation Patterns and Energy Audit of E. coli B/r and K-12

  • Lee, Jin-Won;Goel, Akshay;Ataai, Mohammad-M.;Domach, Michael-M.
    • Journal of Microbiology and Biotechnology
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    • v.12 no.2
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    • pp.258-267
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    • 2002
  • A flux determination methodology has been built which enables to develop constrained stoichiometric relationships and metabolic balances. The analysis differs from those developed for anaerobic growth conditions in that cell mass formation is a significant sink for carbon. When combined with experimental measurements, a determined system of equations results yielded tricarboxylic acid (TCA) cycle and glycolytic fluxes. The methodology was implemented to determine the fluxes of E. coli B/r and K12, and it was found that as the growth rate in a glucose minimal medium increased, the cells became increasing glycolytic and the TCA fluxes either leveled off or declined. The pattern identified for the TCA fluxes corresponded to ${\alpha}$-ketoglutarate dehydrogenase's induction-repression pattern, thereby suggesting that the induction-repression of the enzyme could result in significant flux changes. When the minimum flux solution was contrasted to the glycolytic and TCA fluxes determined, two observations were made. First, the minimum flux could provide the cell's biosynthetic ATP requirements. Second, at a high growth rate in a glucose medium, the excess glycolytic flux exceeded that of the TCA cycle, which appeared to more closely match the biosynthetic needs.

Secure SLA Management Using Smart Contracts for SDN-Enabled WSN

  • Emre Karakoc;Celal Ceken
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.11
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    • pp.3003-3029
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    • 2023
  • The rapid evolution of the IoT has paved the way for new opportunities in smart city domains, including e-health, smart homes, and precision agriculture. However, this proliferation of services demands effective SLAs between customers and service providers, especially for critical services. Difficulties arise in maintaining the integrity of such agreements, especially in vulnerable wireless environments. This study proposes a novel SLA management model that uses an SDN-Enabled WSN consisting of wireless nodes to interact with smart contracts in a straightforward manner. The proposed model ensures the persistence of network metrics and SLA provisions through smart contracts, eliminating the need for intermediaries to audit payment and compensation procedures. The reliability and verifiability of the data prevents doubts from the contracting parties. To meet the high-performance requirements of the blockchain in the proposed model, low-cost algorithms have been developed for implementing blockchain technology in wireless sensor networks with low-energy and low-capacity nodes. Furthermore, a cryptographic signature control code is generated by wireless nodes using the in-memory private key and the dynamic random key from the smart contract at runtime to prevent tampering with data transmitted over the network. This control code enables the verification of end-to-end data signatures. The efficient generation of dynamic keys at runtime is ensured by the flexible and high-performance infrastructure of the SDN architecture.

A study of the hybrid electric drive generating mode in naval ships (함정용 하이브리드 전기추진 시스템 발전기 모드 적용에 대한 연구)

  • Ryu, Seung-hyun;Jung, Sung-young;Oh, Jin-seok
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.9
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    • pp.967-972
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    • 2015
  • Because of recent interests in energy conservation and prevention of environmental pollution, research related to these topics is increasing. The U.S. Navy has started to study the HED (hybrid electric drive) system in order to improve the COGAG propulsion system's fuel efficiency in AEGIS destroyers. (This ship's fuel consumption is 40% of the total fuel consumption of the U.S. Navy.) In addition, the Korean Navy is considering applications of the HED system in AEGIS destroyers. The purpose of this study is to analyze the U.S.A.'s HED system and to simulate its generating mode energy saving rate using LabVIEW. The results confirmed that the fuel savings are about 700 kg/h.

Sustainability Criteria Identified in the Global Sourcing Practices of Global Fashion Retailers (글로벌 패션 기업의 해외 소싱 프로세스에서 나타난 지속 가능성 기준)

  • Lee, Ji Yeon
    • Fashion & Textile Research Journal
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    • v.24 no.2
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    • pp.206-216
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    • 2022
  • This study sought to examine the sustainability criteria found in the global sourcing practices of global fashion retailers. Sustainable supply chain management, with a particular focus on the sustainability criteria of global sourcing, was analyzed. This qualitative study was based on a focus group interview and corporate social responsibility (CSR) annual reports. Eight master categories, 18 middle categories, and 37 bottom categories were extracted. The key categories and their middle categories were as follows: (1) Social compliance (working conditions, employment, safety); (2) Environment concerns (environmental pollution management, eco-friendly production, supply chain environment); (3) Energy efficiency (energy saving program, store environment); (4) Consumer protection (restricted substances management, consumer product safety improvement); (5) Management system (code of conduct, triangle audit system); (6) Community social activities (local community service, voluntary activities, charitable activities); (7) External stakeholder engagement (media & non-governmental organization management, maintenance of relationship with local authority); (8) Brand protection (respect for companies' intellectual property). The findings of this study offer academically significant insights into the sustainability criteria that can be encountered by companies under diverse global sourcing scenarios, revealing that global sourcing by fashion retailers is not merely a means of reducing costs, but a way of generating new jobs and making a social contribution to developing countries. The study's findings also have practical significance, offering guidelines for general CSR activities in the global sourcing process.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

Nutrient Intake Status of Korean Drinkers: Analysis of Data from Korea National Health and Nutrition Examination Survey (KNHANES), 2011 (성인 음주자의 영양소 섭취실태: 2011 국민건강영양조사 자료 분석)

  • Kim, Hyung-Tae;Chun, Sung-Soo;Joung, Sun-Hee;Yun, Mi-Eun
    • Journal of the Korean Dietetic Association
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    • v.19 no.4
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    • pp.343-355
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    • 2013
  • This study analyzed the dietary habits and nutrient intake status of adult drinkers in Korea. Alcohol drinking patterns were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES). Among 4,968 persons, 91.5% were drinkers. Classification of their drinking patterns by the Alcohol Use Disorders Identification Test (AUDIT) score showed 64.5% of the drinkers were normal drinkers, 22.4% problem drinkers and 13.2% alcohol-dependent drinkers. Overall, 47% of the drinkers were considered alcohol-dependent in the Rapid Alcohol Problems Screen (RAPS4). Significant differences were found between those who abstained from alcohol (86.8%) and alcohol-dependent drinkers (68.9%); when asked about breakfast habits 73.4% of non-drinkers often had family meals, while only 55.4% of the alcohol-dependent drinkers had family meals. Dietary energy, alcohol energy, and total energy intake significantly increased for the alcohol-dependents (P<0.001). In addition, the intake of eight nutrients (protein, vitamin A, vitamin $B_1$, vitamin $B_2$, niacin, calcium, phosphorous and iron), significantly increased in the following order (least to highest): abstainers, normal drinkers, drinkers with a moderate addiction to alcohol and alcohol-dependent drinkers (P <0.05). Nutrient Adequacy Ratios (NAR) of all nutrients, except vitamin C, and the Mean nutrient Adequacy Ratio (MAR) significantly increased in the following order (least to highest): abstainers, normal drinkers, drinkers with a moderate addiction to alcohol and alcohol-dependent drinkers (P<0.05). The intake of vitamin $B_1$, vitamin $B_2$, and niacin per 1,000 kcal, according to drinking pattern, decreased in the order of abstainers, normal drinkers, drinkers with a moderate addiction to alcohol, and alcohol-dependent drinkers (P<0.001). The above results show that the nutrient intake of normal drinkers, drinkers with a moderate addiction to alcohol, and alcohol-dependent drinkers are higher than abstainers. However, overall intake of vitamin $B_1$, vitamin $B_2$, and niacin per 1,000 kcal was low. Therefore it is necessary to increase vitamin $B_1$, vitamin $B_2$, and niacin intake for drinkers.

A Confirmatory Factor Analysis for Quality Competitiveness Excellence Company Evaluation Indicators (품질경쟁력 우수기업 평가지표의 확인적 요인분석)

  • Park, Dong Joon;Yun, Yeboon;Yoon, Min
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.3
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    • pp.101-111
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    • 2020
  • Companies struggle to make their best products with high quality and service at a competitive price in global markets. However, customer needs and requirements keep changing with a variety of situations. Companies that face the changes can not stay the same and make an effort to adapt themselves to new circumstances. They would probably review the overall management system that is currently implementing to improve management efficiency. Among other things, quality might be considered to be a crucial element if they are manufacturing industries to be sustained in global markets. KSA (Korean Standards Association) is a government-affiliated organization under the Ministry of Trade, Infrastructure, and Energy. It is a Korean standards provider for quality and service industry. KSA confers national commendations for organizations, quality circles, artisans, QCEC (Quality Competitive Excellent Company), and the most honorable KNQA (Korean National Quality Award) every year. KSA established KNQA on the basis of Malcom Baldrige National Quality Award, Deming Prize, and European Quality Award. Research on quality awards shows that there are many similarities in the framework. Although KSA summarizes two factors for 13 evaluation indicators in the quality competitive excellent model of QCEC, the categorization is ambiguous to explain them according to earlier studies. We performed a deep analysis of foreign quality awards and background for KNQA and QCEC. We conducted a content analysis of KNQA and QCEC and matched evaluation items that were closely related. We proposed a quality competitiveness model with three factors, Technology, System, and Tools, summarizing 13 evaluation indicators in QCEC. Based on audit data for six years from 2012 to 2017 we carried out a confirmatory factor analysis for the proposed model by examining the model validity and fitness.

Evaluation Model for the Stability of the Diagnostic Information System Incorporating the Quantitative Evaluation (정량적 평가를 도입한 정보시스템 안정성 진단 평가 모델)

  • Im, Hyeong-Do;Park, Dea-woo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.313-316
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    • 2016
  • Highly probable cause of the current turmoil critical national infrastructure and private enterprise information systems failures or national event of an accident, it is inevitable huge hit in corporate business as well as a significant impact on the national benefit. This is a trend subject to the stability of the national management information system has a significant impact on people and society, such as banking, telecommunications, transport and energy, which can be extended into a private institution. However, public and private ICT business through the development of Information system Audit or CMMI(Capability Maturity Model Integration) certification check the quality of the target system, but quality check on the reliability of the information system operations after construction is either not promoting met for some safety test results a situation that does not enabled by insufficient. By preventing the disorder or an accident of this study, the diagnostic reliability information systems through inspection and evaluation system development of information systems being established, and to minimize service confusion and study ways to ensure customer - oriented service.

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Structural Integrity Evaluation by System Stress Analysis for Fuel Piping in a Process Plant (공정플랜트 연료배관의 시스템응력 해석에 의한 구조 건전성 평가)

  • Jeong, Seong Yong;Yoon, Kee Bong;Duyet, Pham Van;Yu, Jong Min;Kim, Ji Yoon
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.44-50
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    • 2013
  • Process gas piping is one of the most basic components frequently used in the refinery and petrochemical plants. Many kinds of by-product gas have been used as fuel in the process plants. In some plants, natural gas is additionally introduced and mixed with the byproduct gas for upgrading the fuel. In this case, safety or design margin of the changed piping system of the plant should be re-evaluated based on a proper design code such as ASME or API codes since internal pressure, temperature and gas compositions are different from the original plant design conditions. In this study, series of piping stress analysis were conducted for a process piping used for transporting the mixed gas of the by-product gas and the natural gas from a mixing drum to a knock-out drum in a refinery plant. The analysed piping section had been actually installed in a domestic industry and needed safety audit since the design condition was changed. Pipe locations of the maximum system stress and displacement were determined, which can be candidate inspection and safety monitoring points during the upcoming operation period. For studying the effects of outside air temperature to safety the additional stress analysis were conducted for various temperatures in $0{\sim}30^{\circ}C$. Effects of the friction coefficient between the pipe and support were also investigated showing a proper choice if the friction coefficient is important. The maximum system stresses were occurred mainly at elbow, tee and support locations, which shows the thermal load contributes considerably to the system stress rather than the internal pressure or the gravity loads.

A Study on Planning of Foreign Sailors' Temporary Living Facilities to Prevent the Spread of COVID-19 (COVID-19 확산 방지를 위한 외국인선원 임시생활시설 계획 연구)

  • Oh, Sang-baeg;Lee, Han-seok
    • Journal of Navigation and Port Research
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    • v.45 no.4
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    • pp.194-203
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    • 2021
  • After the outbreak of COVID-19, local infections were spread by foreign sailors of foreign ships entering the ports. However, the government had difficulties in designating temporary living facilities around port areas due to the opposition from local residents. Therefore, the purpose of this study was to plan a floating temporary living facility for foreign sailors in the port area to prevent the spread of COVID-19 by foreign sailors. In this study, location selection, a facility volumetric plan, a unit facility plan, and a unit facility block plan are presented as results of facility planning. Floating temporary living facilities are expected to be used to prevent the spread of first-class infectious diseases in port areas in the future.