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        검색결과 925

        1.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is important to measure the performance of group project but also very important to evaluate the contribution of individual members fairly. The degree of contribution of group members can be assessed by pair-wise comparison method of the Analytic Hierarchy Process. The degree of contribution of group members can be biased in a way that is advantageous to evaluator oneself during the pair-wise comparison process. In this paper, we will examine whether there is a difference in the contribution weight vectors obtained when including evaluator and excluding oneself in the pair-wise comparison. To do this, the experimental data was obtained by making pair-wise comparison in two ways for 15 5-person groups that perform term projects in university classes and 15 pairs of weight vectors for contribution were obtained. The results of the nonparametric test for these 15 pairs of weights vectors are given.
        4,000원
        2.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구의 목적은 척추 자기공명영상 검사 시, 검사시간을 단축할 수 있는 기법인 SENSE와 CS-SENSE를 경추, 흉추, 요추 검사 시 어떤 기법을 적용하는 것이 효과적인지 알아보기 위함이다. 본 연구는 2022년 10월부터 2023년 3월까지 척추질환 및 의심 환자 102명을 대상으로 분석하였다. 사용된 장비는 필립스 사의 3.0T Ingenia Elition X와 20채널 두경부 코일과 44 채널 척추 코일을 사용하였다. 본 연구는 축상 T2강조 고속스핀에코를 SENSE와 CS-SENSE factor 1.5, 2, 3으로 각각 영상을 획득하고, 정량평가는 신호대잡음비와 대조대잡음비를 각 factor 별로 대응 표본 t-test를 진행하였고, 정성평가는 2명의 평가자의 평가점수를 Kruskal-wallis test로 비교하였다. 정량평가 결과, SENSE보다 CS-SENSE가 신호대잡음비와 대조대잡음비가 높게 나왔다. 정성평가 결과, 경추, 요 추는 CS-SENSE 사용 시 평가점수가 높게 나왔고, 흉추는 SENSE 사용 시 평가점수가 높게 나왔다. 결론적으로 척추 MRI 검사 시, 경추, 요추는 CS-SENSE를, 흉추는 SENSE를 사용하는 것이 효과적이다.
        4,200원
        3.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        All-solid-state lithium batteries (ASSLBs) are receiving attention as a prospective next-generation secondary battery technology that can reduce the risk of commercial lithium-ion batteries by replacing flammable organic liquid electrolytes with non-flammable solid electrolytes. The practical application of ASSLBs requires developing robust solid electrolytes that possess ionic conductivity at room temperature on a par with that of organic liquids. These solid electrolytes must also be thermally and chemically stable, as well as compatible with electrode materials. Inorganic solid electrolytes, including oxide and sulfide-based compounds, are being studied as promising future candidates for ASSLBs due to their higher ionic conductivity and thermal stability than polymer electrolytes. Here, we present the challenges currently facing the development of oxide and sulfide-based solid electrolytes, as well as the research efforts underway aiming to resolve these challenges.
        4,000원
        4.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent automated manufacturing systems, compressed air-based pneumatic cylinders have been widely used for basic perpetration including picking up and moving a target object. They are relatively categorized as small machines, but many linear or rotary cylinders play an important role in discrete manufacturing systems. Therefore, sudden operation stop or interruption due to a fault occurrence in pneumatic cylinders leads to a decrease in repair costs and production and even threatens the safety of workers. In this regard, this study proposed a fault detection technique by developing a time-variant deep learning model from multivariate sensor data analysis for estimating a current health state as four levels. In addition, it aims to establish a real-time fault detection system that allows workers to immediately identify and manage the cylinder’s status in either an actual shop floor or a remote management situation. To validate and verify the performance of the proposed system, we collected multivariate sensor signals from a rotary cylinder and it was successful in detecting the health state of the pneumatic cylinder with four severity levels. Furthermore, the optimal sensor location and signal type were analyzed through statistical inferences.
        4,200원
        5.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research introduces an innovative approach for evaluating the degree of densification of carbon nanotube (CNT) sheets produced through direct spinning and subsequently treated with organic solvent (specifically ethanol). Analysis of the morphological features of the CNT sheets from the FE-SEM image affirms that the sheet’s structure becomes more densified following the treatment. Based on this, the treated CNT sheet was comprehensively evaluated using Raman spectroscopy. The results indicate a downward shift in the G′ band, signifying the densification of the CNT sheet’s structure due to the C–C bond weakening by the cohesive force. Following ethanol treatment, the CNT sheet exhibited enhanced electrical conductivity and tensile strength, measuring approximately 1.7 × 105 S m− 1 and 138.7 MPa, respectively, a remarkable improvement of roughly 300% compared to the untreated CNT sheet. This study underscores the efficacy of Raman spectroscopy as a powerful tool for assessing the densification of CNT sheets.
        4,000원
        11.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The lithium-ion battery has been utilized in various fields including energy storage system, portable electronic devices and electric vehicles due to their high energy and power densities, low self-discharge, and long cycle-life performances. However, despite of various research on electrode materials, there is a lack of research on developing of binder to replace conventional polymer-based binding materials. In this work, petroleum pitch (MP-50)/polymer (polyurethane, PU) composite binder for lithium-ion battery has fabricated not only to use as a binding material, but also to re-place conventional polymer-based binder. The MP-50/PU composite binder has also prepared to various ratios between petroleum pitch and polymer to optimize the physical and electro-chemical performance of the lithium-ion battery based on the MP-50/PU composite binder. The physical and electrochemical performances of the MP-50/PU composite binder-based lithium-ion battery were evaluated using a universal testing machine (UTM), charge/discharge test. As a result, lithium-ion battery based on the MP-50/PU composite (5:5, mass ratio) binder showed optimized performances with 1.53 gf mm− 1 of adhesion strength, 341 mAh g− 1 of specific discharge capacity and 99.5% of ICE value.
        4,000원
        12.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.
        4,000원
        13.
        2024.04 구독 인증기관·개인회원 무료
        왕피천 수계 내 저서성 대형무척추동물의 군집구조 분석을 위해 총 5개 지점에서 2023년 총 4회(4월, 6월, 8월 11월) 조사를 실시하였다. 조사기간 중 저서성 대형무척추동물은 총 5문 7강 17목 77과 156종 17,179.1개체/㎡가 채집되었다. 수환경 변화에 민감한 E.P.T. 분류군은 전체 156종 중 91종이 출현하여, 전체 출현종의 58.3%를 차지 하였다. 섭식기능군(FFGs) 분석결과, 종 출현 양상은 육식성 포식자(Predator: P)가 51종(32.69%)으로, 개체 출현 양상은 주워먹는 무리(Gathering-collector: GC)가 6,867.2개체/㎡(39.97%)로 높은 비율로 출현하였다. 서식기능 군(FHGs) 분석결과, 붙는 무리(Clinger: CL)가 70종(44.87%), 12,720.6개체/㎡(74.04%)로 가장 높은 비율로 출현 하였다. 군집지수 분석결과, 우점도지수(DI) 0.43, 다양도지수(H′) 3.51, 풍부도지수(R1) 4.59 균등도지수(J′) 0.77 로 나타났다. 생물학적 수질 판정 지수(BMI) 분석결과, 평균 92.36(±0.83)으로 모든 지점에서 “매우 좋음”으로 판정되었다.
        14.
        2024.04 구독 인증기관·개인회원 무료
        곤충병원성 선충인 Heterorhabditis. megidis(큰형광병원선충)는 참나무 군락지(광주광역시 소재) 사양토에 서 분리 동정되었고, 곤충병원성을 가지는 공생세균은 Photorhabdus temperata로 분리 동정되어 각각 GJ1-2로 명명하였다. H. megidis GJ1-2는 고구마(주황미) 큰 검정풍뎅이 Holotrichia parallela에 대한 방제 효과는 평택시 (경기도 소재)와 논산시(충청북도 소재)의 노지 재배 사양토에서 관주처리 30일 후 각가 81.1%, 78.9%로 나타났 으며, 인삼(재래종) 거세미나방 Agrotis segetum에 대한 방제 효과는 이천시(경기도 소재)와 청주시(충청북도 소재)의 비가림 재배(차광막 설치) 사양토에서 관주처리 14일 후 방제가는 각각 79.9%, 80,2%로 나타났다. H. megidis GJ1-2는 고구마(주황미)와 인삼(재래종)에서 약제 처리 후 3, 7, 14일 후 외관상 약해는 나타나지 않았다.
        15.
        2024.04 구독 인증기관·개인회원 무료
        The blackish cicada, Cryptotympana atrata Fabricius, 1775 (Hemiptera: Cicadidae) was originally distributed mainly in the southernmost remote island, Jeju and rarely throughout low lands in South Korea, but has been explosively increased at the urban areas, where annual temperature is higher. In this study, we sequenced a partial mitochondrial COI from a total of 171 individuals collected throughout 12 localities in South Korea. The haplotype found with the highest frequency in Jeju island shares only with two inland localities in southern region with a low frequency, whereas the haplotype found with the highest frequency throughout inland localities was not found in Jeju island. These results showed that Jeju population, southern region, and other inland populations form somewhat different genetic groups.
        16.
        2024.04 구독 인증기관·개인회원 무료
        국내 농작물에 크게 피해를 주고 있는 파밤나방, 담배거세미나방과 담배나방에 대하여 2020년부터 4년 동안 7월과 9월에 전국 7개 지역의 발생 추이를 조사하였다. 조사지역은 경기도 안성, 충청북도 청주, 강원도 횡성, 경상북도 김천과 안동, 경상남도 창녕, 전라북도 김제를 포함하고 있다. 각 해충의 포획 마릿수는 2021년과 2022 년도에 크게 다르지 않았으며, 지역 간 해충 발생 수준도 비슷하였다. 2021년도와 2022년도와 비교해서 2023년도 에 담배거세미나방과 파밤나방은 각각 119% 및 70% 증가했지만, 담배나방은 23% 감소하였다. 전체적으로 지역 별 발생 시기 및 발생량이 매년 차이를 보이는 것은 기후 등 환경변화의 영향이 가장 큰 것으로 사료 된다. 전체 해충 포획수는 파밤나방이 가장 많고, 담배나방의 수가 가장 적었다. 전년 대비 담배거세미나방과 파밤나방의 경우 중부지역이 남부에 비해 더 많이 발생하였다. 9월에 더 많이 포획되어 전년과 유사한 경향을 보였으며, 최근 3년 동안 9월 발생 밀도가 가장 높았다. 담배나방은 전년에 비해 발생량이 급감하였으며, 안성지역을 제외한 대부분 지역에서 감소하였다.
        17.
        2024.04 구독 인증기관·개인회원 무료
        2023년 경상북도 상주시 떫은감 과수원에서 잎 표피아래 굴을 파고 들어가면서 원형 또는 부정형의 식흔자국 을 남기는 증상을 관찰하였다. 해충의 유충은 녹색에서 적색으로 변하며 번데기 단계를 거쳐 성충(길이 3㎜, 갈색) 이 되어 탈출하였다. 본 해충에 대해 잎에서의 피해증상과 실험실에서 유전분석 결과 Genbank(GU816671,486bp DNA liner, 2016)에 등재되어 있는 감잎가는나방(Cuphodes diospyrosella)으로 동정되었다. 일본에서 1957년 최초 보고 후 우리나라에서는 주로 경남 창원과 진주의 농약 무살포 및 유기농 단감원에서 발생하였으나, 이번 경북지 역에 처음 발견되어 떫은감 재배 농업인과 현장지도원의 감잎가는나방에 대한 피해증상 진단에 활용할 수 있을 것으로 생각된다.
        18.
        2024.04 구독 인증기관·개인회원 무료
        The large copper butterfly Lycaena dispar (Haworth, 1803; Lepidoptera: Lycaenidae) has been categorized as a near-threatened species (NT) in South Korea from 2012 mainly due to limited distribution. In this study, we visited 36 sites spread across all South Korean provinces to verify the distributional range of the species and sequenced mitochondrial COI for 53 individuals from nine sites. We observed L. dispar at 15 sites in six provinces, including the two previously known provinces, indicating a southward range expansion. The in-field monitoring and genetic data collectively suggested that L. dispar does not have a limited distribution nor is it isolated, indicating that it should be reclassified as less vulnerable. Our study demonstrates that the combination of field and genetic data can provide a more reliable assessment of the stability of a species.
        19.
        2024.04 구독 인증기관·개인회원 무료
        The recent increase in the occurrence of common bed bug and tropical bed bug in shared areas highlights the need for rapid species identification at infestation sites, which is crucial for implementing targeted control measures due to differences in genetic and physiological traits. In this study, molecular diagnostic methods were developed using species-specific ITS2 sequences. Both multiplex PCR and loop-mediated isothermal amplification (LAMP) protocols with a DNA release method successfully distinguished between the two bed bug species regardless of developmental stages in 0.5~2.5 hours, even with dead specimens. Especially, LAMP's simplicity and speed make it applicable for rapid and accurate bed bug diagnosis at infestation sites.
        20.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        GN01 is a new antiviral medicine acting against Korean Sacbrood virus (KSBV) of honeybees. It contains 5 mg/mL of active ingredient, double stranded RNAs(dsRNA), that homologous to KSBV ribonucleic acid coding coat protein (VP1) of virus and inducing RNA interference (RNAi). RNA medicine is generally recognized as safe for rapid breakage by intrinsic ribonuclease and limited absorption from gastrointestinal tract. However, there were no data of repeat-dose toxicity in laboratory animals for dsRNA targeting SBV. This study was performed to investigate toxicity of GN01 in SD rats after weekly oral dosing for 28 days and to determine its no-observed-adverse-effect-level (NOAEL). Male and female SD rats were orally administered with GN01 at 0, 25, 50 and 100 mg/kg bw/day of dsRNA once per week for 28 days (total 5 administrations). The highest dose 100 mg/kg bw/day was determined based on the maximum volume injectable (20 mL/kg bw) via gavage. During treatment period, clinical signs, functional and sensory responses, body weights, food and water consumption, ophthalmological findings and urinalysis were investigated. After treatment period, hematological and clinical biochemistry tests and examination of necropsy findings, organ weights and histopathological lesions were performed. There were no significant differences between all test groups and vehicle control group in all measured parameters. Therefore, the NOAEL of GN01 was determined 100 mg/kg bw/day, the highest dose administered. In conclusion, repeated oral administration of GN01, a dsRNA medicinal product, is safe even at the maximum available dose in rats.
        4,900원
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