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        검색결과 55

        1.
        2023.11 구독 인증기관·개인회원 무료
        When occurring at a nuclear power plant (NPP) by accidents, accurate prediction and identification of the process of radioactive material dispersing into atmosphere is important to protect public and environment. Atmosphere dispersion of radioactive materials is significantly influenced by wind direction and wind speed. The government and nuclear operator continuously monitor wind data at nuclear sites through meteorological tower to prepare for such accidents involving the release of radioactive materials. The purpose of this study is to construct wind rose diagrams at 5 NPP sites (Kori, Saewool, Wolsong, Hanbit, Hanul). Wind roses serve as invaluable tool for identifying wind patterns in each region and visualizing wind directions. This can be utilized to predict the dispersion pathway and extent range of radioactive materials carried by the wind. This program will take on the role of establishing appropriate evacuation routes or shelter locations for residents when reliable wind data is not immediately available during an NPP accident. The wind data used in the study was collected from a meteorological tower located at the NPP site, and measurements were taken at 1-hour intervals for each operation over a period of ten years. The collected data underwent preprocessing, followed by the development of Python code to render the wind rose diagrams in an interpretable format. The future direction of this study will be focused on enhancing this program by integrating geographical mapping capabilities. With these advancements, it will become feasible to superimpose shelter positions on a map in accordance with prevailing wind directions. These improvements will contribute to the development of additional protective measures for residents and the proposal of alternative shelter options in response to potential radioactive material releases.
        2.
        2023.05 구독 인증기관·개인회원 무료
        In the event of a radioactive release, it is essential to quickly detect and locate the source of the release, as well as track the movement of the plume to assess the potential impact on public health and safety. Fixed monitoring posts are limited in their ability to provide a complete picture of the radiation distribution, and the information they provide may not be available in real-time. This is why other types of monitoring systems, such as mobile monitoring, aerial monitoring, and personal dosimeters, are also used in emergency situations to complement the information provided by fixed monitoring posts. Also, the monitoring system can be improved by using the Kriging technique, which is one of the interpolation methods, to predict the radiation dose in the relevant districts. This can be achieved by utilizing both the GPS information and the radiation dose measured at a particular point. The Kriging method involves estimating the value between different measurement points by considering the distance between them. The model used GPS and radiation data that were measured around the Hanbit NPP. The data were collected using a radiation measuring detector on a bus that traveled around the NPP area at 2-second intervals for one day. From the collected data, 200 data points were randomly selected for analysis, excluding the data measured at the bus garage out of a total of 16,550 data points. The average dose of the daily measurement data was 117.94 nSv/h, and the average dose of the 200 randomly extracted data was 119.17 nSv/h. The GPS and radiation dose data were utilized to predict the radiation dose around the Yeonggwang area where the Hanbit NPP is located. In the event of an abnormal release of radioactive material, it can be difficult to accurately determine the dose unless a monitoring measurement point is present. This can delay the rapid evacuation of residents during an emergency situation. By utilizing the Kriging model to make predictions, it is anticipated that more accurate dose predictions can be generated, particularly during accident scenarios. This can aid in the development of appropriate resident protection measures.
        3.
        2022.10 구독 인증기관·개인회원 무료
        Republic of Korea (ROK) is operating the Integrated Environmental Radiation Monitoring Network (IERNet) in preparation for a radioactive emergency based on Article 105 of the Nuclear Safety Act (Monitoring of Nationwide Radioactive Environment). 215 radiation monitoring posts are monitoring a wide area, but their location is fixed, so they can’t cover areas where the post is not equipped around the Nuclear Power Plants (NPPs). For this, a mobile radiation monitoring system was developed using a drone or vehicle. However, there are disadvantages: it is performed only at a specific cycle, and an additional workforce is required. In this study, a radiation monitoring system using public transportation was developed to solve the above problems. Considering the range of dose rates from environmental radiation to high radiation doses in accidents, the detector was designed by combining NaI (TI) (in the low-dose area) and GM detector (in the high-dose area). Field test was conducted by installed on a city bus operated by Yeonggwang-gun to confirm the performance of the radiation monitoring system. As a result of the field test, it was confirmed that data is transmitted from the module to the server program in both directions. Based on this study, it will be possible to improve the radiation monitoring capability near nuclear facilities.
        4.
        2022.05 구독 인증기관·개인회원 무료
        Once a radioactive material is released from the nuclear power plant (NPP) by accident, it is necessary to understand the behavior of radioactive plume to protect residents adequately. For this, it is essential to measure the radiation dose rate around NPPs at important locations. Our previous study developed a movable radiation detector that can be installed quickly in an accident to measure gamma dose rate in areas where environmental radiation monitoring system is not installed. The data measured by the detector are transmitted to the server in real-time through LoRA wireless communications. There are two methods to use LoRA communications; one is self-network, and the other is the network provided by the mobile carrier. A signal receiver, called a gateway, should be equipped near the installation location of radiation detectors to use a self-network without using the mobile carrier’s system. In other words, the movable radiation detectors we made can function if there should be any gateway near them. The distance capable of communication between gateway and detector is about 8 km in an open area without significant obstacles. Korea has many significant obstacles, such as mountains around most NPPs. Thus, the gateways could be installed in the proper position before the accident to operate the movable radiation detectors without problems. If the gateway is located at a high position like a mountain top, it could cover a wide area. In this study, the elevation database in the area around the NPPs was collected and analyzed to determine where gateways should be installed. The analysis range is limited in the urgent protective action planning zone. The optimization was also performed to minimize the number of gateways.
        5.
        2020.11 구독 인증기관 무료, 개인회원 유료
        Online search advertising (aka, sponsored or paid search advertising) is a technology that any matched advertisement is displayed on Web pages as online users’ query results from search engines and Web portals (e.g., Google, Bing, Baidu, Naver, and Yahoo!). In specific, after online users type search keywords on the search box (at this stage, online users become searchers), search engines match users’ query texts to phrases included in search advertisement. Then, if an advertiser’s investment on her/his search advertisement is high enough, the advertisement is likely to be displayed on a search engine results (called “impression”) (Hanson and Kalyanam 2007; Jansen et al. 2009; Jansen and Clark 2017; Moore, Stammerjohan, and Coulter 2005). Once a searcher clicks a displayed advertisement and arrives on the advertiser’s landing page, s/he becomes a visitor by clicking the impression. As benefits of utilizing search keywords, online search advertising can reduce search costs and increase information accessibility by potential customers. In addition, because online search advertising provides relevant search results based on the users’ own queries, it is considered less intrusive than banner advertisement and widely used by many marketers (Ghose and Yang 2009; Johnson, Bruner, and Kumar 2006; Quinton and Khan 2009; Rangaswamy, Giles, and Seres 2009; Yang and Ghose 2010).
        3,000원
        6.
        2020.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 고리 1호기 해체 비용 추정을 위해 외국 원자력발전소 해체 비용 데이터를 현가화한 후 원자력발전소 해체 비용 추정 회귀 분석모델을 개발하였다. 이 모델 개발에 사용된 데이터는 해체 또는 진행 중인 BWR 13기, PWR 16기의 해체 비용 데이터이다. 회귀 분석모델 도출을 위해, 해체 비용을 종속변수로 정하고, 해체 원전의 운전 특성을 반영할 수 있게 고 안된 Contamination factor와 해체 기간을 독립변수로 선정하였다. 빅데이터 분석 도구인 R language의 통계패키지를 이용 하여 회귀 분석모델을 도출하였다. 이 회귀 분석 모델을 적용하여 고리 1호기 해체 비용을 예측한 결과, 미화 663.40~928.32 백만 달러, 한화 약 7,828.12억~1조 954.18억 원이 소요될 것으로 예측되었다.
        4,600원
        7.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Stroke patients experience multiple dysfunctions that include motor and sensory impairments. Therefore, new intervention methods require a gradational approach depending on functional levels of a stroke patient’s activity and should include cognition treatment to allow for a patient’s active participation in rehabilitation. Objects: This study investigates the effect of integrated revision of electrical sensory stimulation, which stimulates somatosensory and action observation training, which is synchronized cognition intervention method on stroke patients’ functions. Methods: Twenty-one stroke patients were randomized into two groups. The two groups underwent twenty minutes of intervention five times a week for three weeks. This study used an electromyogram to evaluate symmetric muscle activation of lower extremities and muscle onset time when performing sit to stand before and after intervention. A weight-bearing ratio was used to evaluate the weight-bearing of the affected side in a sit to standing. To evaluate sit to stand performance ability, this study performed five timed sit to stand tests. Results: The two groups both showed statistically significant improvement in muscle onset time of lower extremity, static balance ability in a standing position, and sit to stand performance after the intervention (p < 0.05). In addition, the action observation and synchronized electrical sensory stimulation group showed significant improvement in symmetric muscle activation of lower extremities and weight–bearing ratio of the affected side (p < 0.05). Conclusion: action observation and synchronized electrical sensory stimulation (AOT with ESS) can have positive effects on a stroke patient’s sit to stand performance, and the intervention method that provides integrated AOT with ESS can be used as new nervous system intervention program.
        4,000원
        8.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Stroke patients have reduced trunk control compared to normal people. The ability to control the trunk of a stroke patient is important for gait and balance. However, there is still a lack of research methods for the characteristics of stroke control in stroke patients. Objects: The aim of this research was to determine whether trunk position sense has any relation with balance and gait. Methods: This study assessed trunk performance by measuring position sense. Trunk position sense was assessed using the David back concept to determine trunk repositioning error in 20 stroke patients and 20 healthy subjects. Four trunk movements (flexion, extension, lateral flexion, rotation) were tested for repositioning error and the measurement was carried out 6 times per move; these parameters were used to compare the mean values obtained. Subjects with stroke were also evaluated with clinical measures of balance and gait. Results: There were significant differences in trunk repositioning error between the stroke group and the control group in flexion, lateral flexion to the affected side, lateral flexion to the unaffected side, rotation to the affected side, and rotation to the unaffected side. Mean flexion error: post-stroke: 7.95 ± 6.76 degrees, control: 3.32 ± 2.27; mean lateral flexion error to the affected side: 6.13 ± 3.79, to the unaffected side: 5.32 ± 3.15, control: 3.57 ± 1.92; mean rotation error to the affected side: 8.25 ± 3.09, to the unaffected side: 9.24 ± 3.94, control: 5.41 ± 1.82. There was an only significant negative correlation between the repositioning error of lateral flexion and the Berg balance scale score to the affected side (–0.483) and to the unaffected side (–0.497). A strong correlation between balance and gait was found. Conclusion: The results of this study indicate that stroke patients exhibit greater trunk repositioning error than age-matched controls on all planes of movement except for extension. And lateral flexion has correlation with balance and gait.
        4,000원
        9.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerous studies have reported that good adhesion and fluorination of carbon materials in a fluoropolymer matrix enhance their electrical and mechanical properties. However, a composite reinforced with oxyfluorinated graphite has not been reported for improving mechanical properties. This paper discusses the fabrication of conductive fluorinated ethylene–propylene (FEP)/oxyfluorinated graphite (f-graphite) composite bipolar plates (BPs) via compression molding. To investigate the effects of fluorinating graphite, graphite with a large particle size of 500 μm was mixed with FEP powder with a small particle size of 8 μm through ball milling. The FEP/graphite composites exhibited high anisotropic electrical conductivity with the in-plane conductivity much higher than the through-plane conductivity because of the planar orientation of the graphite sheets. Therefore, the mechanical properties of the composites such as flexural strength tended to deteriorate with increasing graphite content. In particular, the FEP/f-graphite composites exhibited excellent flexural strength of 12 MPa, much higher than that of FEP/graphite composites at 9 MPa with a graphite content of 80 wt%. The interfacial interaction between FEP and f-graphite led to improved physical compatibilization, which contributed to enhance the mechanical properties of these composites. Our results are a step toward developing BPs for use in high-temperature fuel cells and heat-sink components.
        4,000원
        11.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Flat-footed persons with collapsed medial longitudinal arch lose flexibility after skeletal maturity, resulting in several deformities and soft tissue injuries. Although arch support taping is usually applied in the clinic to support the collapsed arch, research on the use of different types of tape for more efficient arch support in flat-footed persons is lacking. Objects: The purpose of this study was to examine three conditions (barefoot, kinesio tape, and dynamic tape) and compare their effects on static and dynamic balance in persons with asymptomatic flexible flatfoot. Methods: Twenty-two subjects (9 females and 13 males) with asymptomatic flexible flatfoot participated in this study. The subjects performed the Y-balance test to measure the composite reach score. The subjects also performed a 30-second standing test to measure the center of pressure (COP) path length and a walking test to measure anteroposterior and lateral variability using the Zebris FDM system. One-way repeated-measures analysis of variance compared the three conditions applied to the subjects’ feet for each balance variable. Results: The composite reach score significantly increased following the application of dynamic tape compared with barefoot and that of kinesio tape compared with barefoot. There was no significant difference in the COP path length during standing among the three conditions. Anteroposterior and lateral variability during walking significantly with dynamic tape application compared with barefoot. Conclusion: The results of this study suggest that, in persons with asymptomatic flexible flatfoot, application of kinesio tape and dynamic tape may be effective in increasing the composite reach score in Y-balance test, whereas application of dynamic tape may be effective in reducing anteroposterior and lateral variability during walking.
        4,000원
        13.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Compared to healthy people, patients with chronic lower back pain have reduced balance abilities which may cause proprioception problems, patients with chronic lower back pain avoid physical activities due to pain, and reduced activity levels lead to muscle weakening, which can further exacerbate pain. Recently, there have been many studies on the use of sensory stimulation; and among these studies, interventions that use vibrational stimulation have shown functional improvements in the patients. Objects: This study examined the effects of a stabilization exercise with vibration stimulation on the balance ability and disability in patients with chronic back pain. Methods: The subjects of the study were 30 persons who were randomly assigned to the experimental group and the control group, with 15 subjects in each. The subjects were evaluated before and after intervention via a balance ability test, the Korean Oswestry disability index (KODI) test, a pain test, and a proprioceptive sensory test. Both groups received general physical therapy. The experimental group performed the stabilization exercise with vibration stimulation, and the control group performed a general stabilization exercise, three times a week for six weeks. Results: After the intervention, both groups showed significant improvements in the balance ability test, the KODI test, the pain test, and the proprioceptive sensory test. The experimental group showed statistically significant, higher improvements than the control group in the balance ability test, the KODI test, and the proprioceptive sensory test. Conclusions: The stabilization exercise with vibration stimulation for patients with chronic back pain has been reported to provide greater functional improvements than the conventional intervention method. Therefore, the stabilization exercise in a vibration stimulation environment could be a useful intervention for patients with chronic back pain.
        4,000원
        14.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        각종 비즈니스와 거래가 이루어지는 사이트에서 고객과 서비스 공급자와의 소통은 중요한 문제이다. 특히 어떠한 문제가 발생해 문의가 들어왔을 때 그 문제를 빠르고 정확하게 해결하는 능력은 사이트에 대한 신뢰와도 직결된다. 본 논문에서는 재능마켓 플랫폼 사이트에서 챗봇 기술을 이용해 사이트 이용자들의 불평과 문의를 처리하는 방식을 제안한다. 우선 문의자와 실시간으로 대화할 수 있는 챗봇을 구현하여 사이트 이용법, 단어 검색 등의 기능을 이용할 수 있게 하였다. 몇 단어 혹은 문장으로 정의하기 힘든 사이트의 각종 오류와 문제에 대해서는 에러코드를 지정해 데이터베이 스화시켰다. 사이트 이용자들은 오류 발생 시 출력되는 에러코드를 챗봇에 문의하여 그에 대응하는 답변을 실시간으로 얻을 수 있었다. 본 연구에서 구현한 챗봇은 사이트 이용 시 오류를 경험하거나 문의가 생긴 이용자에게 빠르고 정확한 답변을 줄 수 있어 만족스러운 경험을 제공했다. 이는 장기적으로 사이트의 신뢰성과 호감도에 긍정적인 영향을 주고 오류 문의 등에 들어가는 인력과 시간 비용을 줄이는 등의 도움을 줄 것으로 예상된다.
        4,000원
        15.
        2018.07 구독 인증기관·개인회원 무료
        Celebrity endorsement is defined as an agreement between a publicly recognized celebrity and an entity to use the celebrity’s fame to promote a brand or product. Generally, a celebrity is defined as a famous singer, actor, or athlete who frequently appears in public. The celebrity uses his/her public recognition to persuade consumers to purchase a specific product by the endorsement, and the celebrity accepts remunerations from the firm. Celebrity endorsement has been prevalent as an advertising strategy and many advertisers invest enormous amount of money for the celebrity endorsement. Prior research has examined the economic benefits or effectiveness of celebrity endorsement and found that celebrity endorsement attracts attention from consumers and polishes a tarnished brand image, and the celebrity may help advertisements stand out, thus improving their communicative ability. Apart from a general celebrity endorsement advantage, previous studies have found the factors that affect the success or failure of celebrity endorsement. An attractive celebrity can positively influence advertising evaluation, and a celebrity with expertise can increase consumers’ purchase intention through product. In addition, consumers prefer a product endorsed by a highly trustworthy celebrity. Specifically, on the economic worth of celebrity endorsement, most studies have indicated a positive effect. An announcement of a celebrity endorsement contract can bring a positive abnormal benefit to a firm’s stock price. Celebrity endorsement also helps increase the intangible value of a firm, which is the source of competitive edge and sustainable growth. However, despite recent interest in the return on advertising investment, it is not known how and which source factor of the celebrity endorsement can be explained with the firm value. By using text mining and sentiment analysis, the results of this study explain that the sustainable firm value is impacted by various sources of celebrity endorsement. First, the number of words regarding celebrity attractiveness, expertise, and trustworthiness has an impact on the sustainable firm value. Among the three sources, trustworthiness has the biggest impact on the sustainable firm value, which is Tobin’s Q. Second, regarding attractiveness and expertise, increasing proportion of positive words has impact on the firm value. On the other hand, regarding trustworthiness, the number of negative words on occupational issues is important. Third, different celebrity expertise has different impact on the sustainable firm value depending on the degree of job uniqueness and replaceability. Fourth, once the celebrity has lost his/her trustworthiness, the negative impact is hardly recovered as the negative interaction effect between positive impact of celebrity expertise on the sustainable firm value and the loss of trustworthiness is over seven times higher than the positive effects from the expertise. This implies that if an advertiser carefully manages other effects except for the loss of trustworthiness, he/she cannot offset the failure.
        16.
        2018.04 구독 인증기관·개인회원 무료
        This study was conducted to evaluate the the efficacy of mulberry cake mixed diet on larval growth of Protaetia brevitarsis. As a result of adding 3, 5, and 10% mulberry cake to the fermented mulberry sawdust, the development period of the Protaetia brevitarsis larvae was 44.9days, 44.6days, and 41.8days, and the highest weight of larvae was 2.76g, 2.80g, and 2.89g, respectively. As a result of adding 3, 5, and 10% mulberry cake to the fermented oak sawdust, the development period of the Protaetia brevitarsis larvae was 46.7days, 41.6days, and 41.7days, and the highest weight of larvae was 2.65g, 2.65g, and 2.56g, respectively.
        17.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we propose an efficient two-phase heuristic policy, called an acceptance tolerance control policy, for Infrastructure as a Service (IaaS) cloud services that considers both the service provider and customer in terms of profit and satisfaction, respectively. Each time an IaaS cloud service is requested, this policy determines whether the service is accepted or rejected by calculating the potential for realizing the two performance objectives. Moreover, it uses acceptance tolerance to identify the possibility for error with the chosen decision while compensating for both future fluctuations in customer demand and error possibilities based on past decisions. We conducted a numerical experiment to verify the performance of the proposed policy using several actual IaaS cloud service specifications and comparing it with other heuristics.
        4,000원
        20.
        2013.04 구독 인증기관·개인회원 무료
        Inhibition of acetylcholinesterase (AChE) is one of the important modes of action available for the control of insects. An assessment was made of the electric eel AChE inhibitory activity of 55 endophytic fungi isolated from the leaves of Huperzia serrata collected in Eunshi, Hubei Province, China. Of 55 mycelial extracts and 55 ethyl acetate-soluble fractions from liquid culture of the fungi, the ethyl acetate-soluble fraction of strain ES056 exhibited strong AChE inhibitory activity (88%) at a concentration of 100 μg/mL. Based on morphological characteristics and nuclear ribosomal DNA ITS sequence analysis, this fungus showed greatest similarity to members of the order Eurotiales and was shown to be most closely related to members of the Aspergillus aculeatus group. It was designated Aspergillus sp. MY056. This strain merits further study as a potential anti-AChE product.
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