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        검색결과 43

        4.
        2023.11 구독 인증기관·개인회원 무료
        In the nuclear fuel cycle (NFC) facilities, the failure of Heating Ventilation and Air Conditioning (HVAC) system starts with minor component failures and can escalate to affecting the entire system, ultimately resulting in radiological consequences to workers. In the field of air-conditioning and refrigerating engineering, the fault detection and diagnosis (FDD) of HVAC systems have been studied since faults occurring in improper routine operations and poor preventive maintenance of HVAC systems result in excessive energy consumption. This paper aims to provide a systematic review of existing FDD methods for HVAC systems therefore explore its potential application in nuclear field. For this goal, typical faults and FDD methods are investigated. The commonly occurring faults of HVAC are identified through various literature including publications from International Energy Agency (IEA) and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). However, most literature does not explicitly addresses anomalies related to pressure, even though in nuclear facilities, abnormal pressure condition need to be carefully managed, particularly for maintaining radiological contamination differently within each zone. To build simulation model for FDD, the whole-building energy system modeling is needed because HVAC systems are major contributors to the whole building’s energy and thermal comfort, keeping the desired environment for occupants and other purposes. The whole-building energy modeling can be grouped into three categories: physics-based modeling (i.e., white-box models), hybrid modeling (i.e., grey-box models), and data-driven modeling (i.e., black-box models). To create a white-box FDD model, specialized tools such as EnergyPlus for modeling can be used. The EnergyPlus is open source program developed by US-DOE, and features heat balance calculation, enabling the dynamic simulation in transient state by heat balance calculation. The physics based modeling has the advantage of explaining clear cause-and-effect relationships between inputs and outputs based on heat and mass transfer equations, while creating accurate models requires time and effort. Creating a black-box FDD model requires a sufficient quantity and diverse types of operational data for machine learning. Since operation data for HVAC systems in existing nuclear cycle facilities are not fully available, so efforts to establish a monitoring system enabling the collection, storage, and management of sensor data indicating the status of HVAC systems and buildings should be prioritized. Once operational data are available, well-known machine learning methods such as linear regression, support vector machines, random forests, artificial neural networks, and recurrent neural networks (RNNs) can be used to classify and diagnose failures. The challenge with black-box models is the lack of access to failure data from operating facilities. To address this, one can consider developing black-box models using reference failure data provided by IEA or ASHRAE. Given the unavailability of operation data from the operating NFC facilities, there is a need for a short to medium-term plan for the development of a physics-based FDD model. Additionally, the development of a monitoring system to gather useful operation data is essential, which could serve both as a means to validate the physics-based model and as a potential foundation for building data-driven model in the long term.
        5.
        2023.10 구독 인증기관·개인회원 무료
        Cryptotympana atrata belongs to the family Cicadidae, has long been recognized as a damaging plant-sucking pest, and is distributed in East Asian countries. In addition, their cries cause direct harm to us through noise pollution and also reported twig damage in the forest environments. In this study, we isolated strains of the entomopathogenic fungus Metarhizium that occurred from C. atrata collected this year. Here, we provide the morphological character and molecular phylogenetic relationship of this species. This is the first record of the entomopathogenic fungus Metarhizium viridulum isolated from C. atrata in Korea and provides a candidate strain with potential use for biological agents.
        6.
        2023.07 구독 인증기관·개인회원 무료
        With the infusion of advanced technology, interactions between customers and firms’ representatives take place in brick-and-mortar stores, 2D online sites, and even 3D metaverse environments. In the metaverse, a firm’s sales avatars interact with other users while representing the firm, recommend, and sell virtual items. Previous literature about the effectiveness of sales representatives agrees that a firm representatives’ smiling faces engender customer satisfaction and better interactions. However, it is unclear whether smiling faces of sales avatars will work the same way in the metaverse as they do in the real world. The current research examines whether a firm’s sales avatars with sad facial expression (vs. those with smiling facial expression) stimulate higher user intentions to interact with firm representative avatars, to purchase virtual items from the representative avatars, and to spread positive WOM about their experience in the metaverse. Moreover, focusing on subcultural appeal, we investigate why this unconventional phenomenon happens in the metaverse unlike in real world. We conducted two experiments to manipulate a firm representative avatar’s facial expression (smiling vs. sad) in the metaverse. We newly designed a metaverse place, and participants who put on a virtual reality headset are exposed to either a hat (Experiment 1) or shoes (Experiment 2) store where they can purchase a virtual hat or shoes. Experiments 1 and 2 basically tested the same things repeatedly. However, to improve internal validity and generalizability, Experiment 2 used human-like sales avatars instead of cartoon character-like sales avatars in Experiment 1, changed virtual stores from a hat store to shoes store, and finally controlled for various extraneous variables such as attractiveness, warmth, and competence of sales avatars, and user’s previous experience about metaverse. Sales representatives with a smile are believed to contribute to beneficial consumers’ attitudes and behaviors in offline stores. However, our experiments demonstrate that this well-received belief does not necessarily apply in the metaverse, where subcultural appeal plays a more critical role. In the metaverse, users evaluate sales avatars with sad facial expression (vs. with smiling facial expression) as more unique and cool (i.e., higher subcultural appeal), leading to their higher intention to interact with the sad sales avatar, to purchase a virtual item, and to spread positive WOM about their experiences. Our results imply that previous findings supported in the offline or 2D online sites may not work the same way in the 3D metaverse.
        7.
        2023.05 구독 인증기관·개인회원 무료
        The Korea Laboratory Accreditation Scheme (KOLAS) is the national accreditation body responsible for providing accreditation services to testing and calibration laboratories. The primary objective of KOLAS is to promote the quality and reliability of laboratory testing by providing nationally and internationally recognized accreditation services. Laboratories accredited by KOLAS are required to meet rigorous international standards set by the International Organization for Standardization (ISO) and are subject to regular assessments to ensure ongoing compliance with the standards. KOLAS accreditation is highly regarded both domestically and internationally, and is recognized for providing high-quality and reliable testing services. The nuclear analysis laboratory at KINAC has been working to establish a quality management system to ensure the external reliability of analytical results and to secure its position as an authorized testing agency. To achieve this, a detailed manual and procedure for nuclear material analysis were developed to conform to the international standards of ISO/IEC 17025. This study presents the preparation process for establishing the management system, focusing on meeting technical and quality requirements for the implementation of the ISO/IEC 17025 standard in the KINAC nuclear analysis laboratory, specifically in the field of chemical testing (dosimetry, radioactive, and neutron measurement subcategories). The preparation process involved two tracks. The first track focused on satisfying technical requirements, with Thermal Ionization Mass Spectrometer (TIMS) and Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) selected as the major equipment for analysis. Analytical methods for determining isotope ratios and concentrations of nuclear materials were determined, and technical qualification was ensured through participation in proficiency test programs, inter-experimenter comparison tests, and uncertainty reports. The second track focused on developing the quality system, including quality manuals, procedures, and guidelines based on the requirements of the ISO/IEC 17025 standard. Various implementation documents were produced during the six-month pilot period, in accordance with the three levels of documents required by the standard. Implementation of ISO/IEC 17025 is expected to have a systematic quality management process for the analysis lab’s operations and to increase confidence in KINAC’s nuclear analysis.
        8.
        2023.05 구독 인증기관·개인회원 무료
        The domestic representative nuclear fuel cycle facilities are post-irradiation examination facility (PIEF) and Irradiated Examination Facility (IMEF) at KAERI. They have regularly operated since 1991 and 1993, respectively. Due to the long period of use, the facilities are ageing, and maintenance costs are increasing every year. The maintenance methods have mainly been breakdown maintenance (BM) and partially preventive maintenance (PM). They involve replacing components that have problems through periodic inspections by on-site inspectors. However, these methods are not only uncertain in terms of replacement cycles due to worker’s deviation on the inspection results, but also make it difficult to respond accidents developed through failures on the critical equipment that confines radioactive material. Therefore, an advanced operation and maintenance studied in 2022 through all of nuclear facilities operated at KAERI. Advancement strategy in four categories (safety, sustainability, performance, innovativeness) was analyzed and their priorities according to a facility environment were determined so a roadmap for advanced operation and maintenance could be developed. The safety and sustainability are higher importance than the performance and innovativeness because facilities at KAERI has an emphasis on research and development rather than industrial production. Thus, strategy for advancement has focused even more on strengthening the safety and sustainability. To enhance safety, it has been identified that immediate improvement of aged structures, systems, and components (SSCs) through large-scale replacement is necessary, while consideration of implementing an ageing management program (AMP) in the medium to long term is also required. Facility sustainability requires strengthening operation expertise through training, education, and cultivation of specialized personnel for each system, and addressing outstanding regulatory issues such as approval of radiation environment report on the nuclear fuel processing facilities and improvement work according to fire hazard analysis. One of the safety enhancement methods, AMP, is a new maintenance approach that has not been previously applied, so it had to be thoroughly examined. In this study, an analysis was conducted on the procedure and method for introducing an AMP. An AMP for nuclear fuel cycle facilities was developed by analyzing the AMP applied to the BR2 research reactor in Belgium and modifying it for application to nuclear fuel cycle facilities. The ageing management for BR2 has the objective to maintain safety, availability and cost efficiency and three-step process. The first step is the classification of SSCs into four classes to apply graded approach. Secondly, ageing risk is assessed to identify critical failure modes, their frequency and precursors. Final step involves defining measures to reduce the ageing risk to an acceptable level in order to integrate the physical and economic aspects of ageing into a strategy for inspection, repair, and replacement. Similar approach was applied to the nuclear fuel cycle facility. Firstly, the SSCs of nuclear fuel cycle facilities have been classified according to their safety and quality classifications, as well as whether they are part of the confinement boundary. The SSCs involved in the confinement boundary were given more weight in the classification process, even if they are not classified as safety-class. A risk index for ageing was introduced to determine which prevention and mitigation measure should be chosen. By multiplying the health index and the impact index, the ageing risk matrix provides a numerical score that represents guidance on the prevention and mitigation of ageing effect. The health index is determined by combining the likelihood of failure and engineering evaluation of the current condition of SSCs, whereas the impact index is calculated by taking into account the severity of consequences and the duration of downtime resulting from a failure. This ageing management has to be thoroughly reviewed and modified to suit each facility before being applied to nuclear fuel cycle facilities.
        11.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The emergence of environmental and social issues has led to global discussions for the realization of sustainable development. The purpose of this study is to propose a method of sustainable fashion design using waste Hanbok, focusing on men's Hanbok with cultural values. The study utilizes literature research and fashion design development. From the literature study, reform was judged to be a higher concept encompassing reduction, recycling, and upcycling. Reduction is a design method through removal, and recycling design transforms from its original form into a completely different product. Upcycling design focuses on improvement and change in functionality. Accordingly, nine redesigns using men’s Hanbok were developed from which three were produced. Consequently, the reduction design demonstrated a small range of variation without changing the item, and cultural sustainability was confirmed through the design that removed the components and recombined the Hanbok. Second, recycling redesign can be reconstituted into a different item. Third, upcycling enables various designs through module assembly, which prolongs the lifespan of the product and confirms its value as a raw material for waste Hanbok. This study is meaningful in realizing sustainable fashion and suggesting practical measures for the sustainability of Korean traditional culture and creative fashion design planning.
        4,500원
        15.
        2020.06 구독 인증기관 무료, 개인회원 유료
        In this study, thirty-eight lactic acid bacteria (LAB) strains were isolated from Kimchi (Korean traditional fermented food) and screened for probiotic characterization in a series of in vitro tests, including resistance to low pH, tolerance to bile salts, hydrophobicity, antibiotic resistance and antioxidant activity. Firstly, twenty-two strains displayed survival in acid and bile passage conditions. Secondly, the strains KCCP 11349 and KCCP 11356 were observed to have high cell surface hydrophobicity with 63.9 and 98.8 %, respectively. Functionality of these potential probiotic isolates was supported by their antioxidant activity. Altogether, the strain KCCP 11349 showed characteristics similar to or even better than reference strain Lactobacillus rhamnosus GG. Finally, 16S rRNA gene sequencing was conducted to identify potential probiotic strains and KCCP 11349 was identified as Lactobacillus plantarum subsp. plantarum.
        4,000원
        17.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 지역아동센터의 원예활동 프로그램 인식과 운영현황을 조사하여 향후 지역아동센터 원예활동 프로그램 발전을 위한 기초자료를 제공하는 것이다. 이를 위하여 충청남도 천안시에 위치한 지역아동센터 소장을 대상으로 2018년 2월 26일부터 2018년 3월 9일까지 방문, 이메일, 전화를 이용하여 설문조사를 실시하였다. 설문을 통해 수집된 자료는 SPSS 23.0 통계 프로그램을 사용하여 빈도분석, 다중응답분석을 실시하였다. 설문조사를 한 결과, 천안시의 지역아동센터 중 원예활동 프로그램을 실행해 본적이 있는 곳은 49%, 실행해보지 않은 곳은 51%로 나타났다. 실행해 본 적이 있는 곳 중 3개월 이상 프로그램을 진행한 센터는 40%에 불과했으며 주 1회, 1시간으로 복지원예사가 진행하였다. 지역아동센터에서 원예활동 프로그램을 시행하지 않은 가장 큰 이유는 ‘예산’이었다. 인지도를 살펴보면, 응답자 중 96.1%가 원예활동 프로그램이 필요하다고 생각하였으며 56.9%가 원예활동프로그램에 매우 관심이 있다고 답하였다. 원예활동 프로그램의 실행으로 지역아동센터가 아동에게 기대하는 효과로는, 정서안정과 사회성 발달에 도움이 될 것이라는 의견이 높게 나타났다. 위의 결과를 종합하여 보았을 때, 많은 소장이 원예활동 프로그램에 관심은 많지만, 일회성 프로그램으로 인식한다고 생각되어 원예활동 프로그램에 대한 정확한 이해와 교육이 필요하다고 사료되며, 앞으로 지역아동센터에서 프로그램을 진행할 때 ‘정서적 안정’과 ‘사회성 향상’을 목적으로 ‘주 1회’로 지속적인 운영을 할 수 있도록 지역아동센터의 예산확보와 원예활동에 대한 적극적인 홍보가 필요하다고 판단된다.
        4,000원
        18.
        2018.10 구독 인증기관·개인회원 무료
        주로 열대와 아열대 지역에 분포하는 순모이리응애속(Euseius Wainstein) 응애류는 이리응애과(Phytoseiidae), 순이리응애아과(Amblyseiinae)에 속하며, 전세계적으로 193종이 보고되었다(Liao et al, 2017). 국내에는 순이리응애(E. finlandicus) 1종만이 기록되어 있다(Ryu, 2012). 잎응애류의 자생 천적자원 탐색조사 도중 본 속의 울릉도산 한국미기록종인 Euseius australis (Wu & Li, 1983)를 새롭게 확인하여 보고한다.
        19.
        2018.10 구독 인증기관·개인회원 무료
        누에는 약제, 면직, 식용, 동물 사료 등에 활용도가 높아 동아시아에서 오랫동안 사육되어 왔다. 뽕잎을 먹고 자란 누에가 사료를 먹고 자란 누에보다 생장주기가 일정하고 더 건강하게 생장한다는 것은 잘 알려진 사실이다. 또한 최근의 연구에 따르면 동물 장내 미생물이 동물의 면역과 생장에 큰 역할을 한다고 알려졌다. 이러한 사실로부터 뽕잎에 존재하는 미지의 미생물이 누에 생장과 면역에 관여할 수 있다는 가설을 세우고 이를 확인하기 위한 연구를 수행하였다. 뽕잎 내생균을 분리하기 위해 뽕잎을 5mm 크기로 잘라 표면살균 후, 배지에 치상하여 자라나오는 세균을 분리하여 동정하였다. 흥미로운 점은 100개 이상의 뽕잎 절편으로부터 동일한 세균이 검출되었으며 계통학적 분석을 통해 동정한 결과, Pseudomonas syringae pv. syringae(Pss)로 확인되었다. 또한, 뽕잎을 섭식한 누에의 장 속과 분변에서 이 균의 존재를 확인하였다. 누에에 병을 일으키는 곤충병원성 곰팡이에 대한 Pss의 항진균 효과를 확인하기 위해 곤충병원성 곰팡이인 Beauveria bassiana, Cordyceps militaris와 식물병원성 곰팡이 Botrytis cinerea, Fusarium graminearum을 대상으로 대치배양을 통해 균사 생장 억제 정도를 확인하였다. 그 결과, 식물병원성 곰팡이의 생장 억제효과는 관찰되지 않았으나 곤충병원성 곰팡이의 생장이 50% 이상 감소되었다. 특히, 다량의 포자를 생성하여 곤충에 치명적인 병을 야기하는 B. bassiana의 균사 생장이 C. militaris에 비해 더 크게 감소하였을 뿐 아니라 Pss의 배양 추출물을 처리하였을 때 B. bassiana의 포자 발아가 지연되었다. 앞으로 누에 장 속에 안착한 Pss가 곤충병원성 곰팡이에 대한 면역력과 누에 생장에 미치는 영향을 확인해 볼 계획이며 이를 통해 건강하고 안정적인 누에 사육에 활용될 수 있는 미생물 제제를 만들고자 한다.
        20.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ultraviolet B (UVB) exposure is a risk factor for skin damage resulting in oxidative stress, inflammation, and cell death. The purpose of this study was to investigate the physicochemical properties of Platycodon grandiflorum (PG) to improve its biological activities using a three-step steaming process. We investigated the protective effects of PG and steamed PG extracts on human dermal fibroblasts (HDFs) against UVB radiation-induced oxidative stress and inflammation as well as the underlying mechanisms. The antioxidant potential of the PG extracts was evaluated by measuring the 2,2-diphenyl-1- picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) scavenging activity. ABTS and DPPH were shown by the 0, 30, and 70% ethanol extracts of 2S-PG and 3S-PG (IC50, 28~45 and 27~30 μg/mL, respectively). Treatment of UVB-irradiated cells with steamed PG (25~400 μg/mL) did not affect their viability. The streamed PG extract suppressed UVB-induced generation of reactive oxygen species (ROS). In addition, streamed PG extract reduced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein expression in UVB-irradiated HDF, regulating nuclear factor (NF)-κB expression. These findings suggest that steamed PG extract may be potentially effective against inflammation associated with UVB-induced oxidation stress.
        4,000원
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