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        검색결과 1,057

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 각 축 방향으로 절대값을 취해 더하는 형태의 맨해튼 거리 측정법을 일반화하 여 2차원 및 3차원에 대한 거리 측정 방법을 제시한다. 또한 이를 이용하여 Worley 노이즈 함수에 적용하여 구현하는데 이용한다. 기존의 방법으로는 2차원에 대해서만 계산이 가능했으 나 제안된 방법에서는 2차원과 3차원에 모두 적용 가능하다. 또한 새로 제안된 방법을 사용하 면 맨해튼 거리를 사용하는 Worley noise함수에 적용할 경우 더 광범위한 패턴 변화를 줄 수 있다. 또한 거리 개념은 매우 다양한 분야에 사용하는 기본 개념이므로 이를 일반화하는 것은 매우 중요한 의미를 가진다고 할 수 있다. 기존의 맨해튼 거리가 2차원에 대해서는 마름모 형 태와 3차원에 대해서는 8면체의 형태로 나타나는 점에 착안하여 이를 확장하고자 한다. 제안 된 방법에서는 매우 간단한 방법을 사용하여 2차원과 3차원에 대해 기존의 유클리드 거리와 맨해튼 거리 개념을 확장하여 일반화된 거리 개념을 제시한다. 이러한 확장된 거리 개념을 Worley 노이즈 함수에 적용함으로써 더 풍부하고 다양한 형태를 얻을 수 있으며 이에 따라 Worley 노이즈를 기반으로 한 프로시저럴 텍스처 패턴 또한 더 다양한 결과를 생성할 수 있 게 된다. 본 연구에서는 새로 제안된 방법을 사용하여 얻을 수 있는 패턴을 실험하여 기존의 거리 개념에서 얻을 수 있는 패턴의 확장된 결과의 예시를 보여줌으로써 제안된 거리 계산 방 법의 유용성을 확인할 수 있도록 한다.
        4,000원
        2.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The small intestine plays a crucial role in animals in maintaining homeostasis as well as a series of physiological events such as nutrient uptake and immune function to improve productivity. Research on intestinal organoids has recently garnered interest, aiming to study various functions of the intestinal epithelium as a potential alternative to an in vivo system. These technologies have created new possibilities and opportunities for substituting animals for testing with an in vitro model. Methods: Here, we report the establishment and characterisation of intestinal organoids derived from jejunum tissues of adult pigs. Intestinal crypts, including intestinal stem cells from the jejunum tissue of adult pigs (10 months old), were sequentially isolated and cultivated over several passages without losing their proliferation and differentiation using the scaffold-based and three-dimensional method, which indicated the recapitulating capacity. Results: Porcine jejunum-derived intestinal organoids showed the specific expression of several genes related to intestinal stem cells and the epithelium. Furthermore, they showed high permeability when exposed to FITC-dextran 4 kDa, representing a barrier function similar to that of in vivo tissues. Collectively, these results demonstrate the efficient cultivation and characteristics of porcine jejunum-derived intestinal organoids. Conclusions: In this study, using a 3D culture system, we successfully established porcine jejunum-derived intestinal organoids. They show potential for various applications, such as for nutrient absorption as an in vitro model of the intestinal epithelium fused with organ-on-a-chip technology to improve productivity in animal biotechnology in future studies.
        4,000원
        3.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구에서는 HMD VR을 사용해 발생한 사이버 멀미와 양안시 기능이 상관관계를 보이는지 알아보고 자 하였다. 방법 : 근거리 시력에 무리가 없는 20~40대 성인 52명을 대상으로 VR 콘텐츠 이용 전 양안시 기능을 측정하기 위해 수평사위도, 조절 근점, 폭주 근점, 양안조절용이성, 입체시, 상대조절력검사를 시행하였다. 광학 흐름 요소로 구분한 세 가지 VR 콘텐츠를 선정하여 대상자에게 사용하도록 하고 Virtual reality sickness questionnaire을 통해 VR 콘텐츠 이용 전과 후의 사이버 멀미를 측정하였다. 양안시 기능과 사이버 멀미에 대한 상관분석을 실시하 였다. 결과 : VR 콘텐츠 사용 후 콘텐츠 T와 R은 모든 항목에서 사이버 멀미(p<0.001)는 유의하게 증가하였다. 콘텐츠 B의 안구운동에서는 유의한 차이가 없었다. 상관분석에서는 근거리 사위가 콘텐츠 T의 방향감각상실(p< 0.050), 전체 VRSQ(p<0.050)와 음의 상관관계를 보였으며, 콘텐츠 R의 안구운동불편(p<0.050)과 유의한 상관관 계가 나타났다. 양안조절용이성은 콘텐츠 T의 전체 VRSQ(p<0.050)와 양의 상관관계를 보였다. 이 외에 다른 양안 시 기능은 사이버 멀미 요인과 유의한 상관관계를 보이지 않았다. 결론 : 양안시 기능은 사이버 멀미와의 결과로 사용자의 개인적 특성이나 양안시 기능 자체가 사이버 멀미에 미 치는 영향보다 3D를 구현하는 콘텐츠의 광학 흐름 요소가 미치는 영향이 더 높다는 것으로 사료된다. 향후 연구에 서는 VR 콘텐츠의 시각 요소와 시지각에 대한 요소가 고려되어야 할 필요성이 있는 것으로 사료된다.
        4,000원
        4.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The physiological functions of the ovary and development of the corpus luteum occur through the activation of endocrine hormones. In this process, estrogen, a reproductive hormone, is secreted in the ovarian follicle and corpus luteum and affects corpus luteum formation and regression. Estrogen controls the synthesis of reproductive hormones by binding to estrogen receptor–α and –β. Estradiol–17β, synthesized in the ovary, regulates the physiological function of the corpus luteum and the angiogenesis signaling pathway. Estrogen controls progesterone synthesis, which is regulated by StAR-transported cholesterol, P450scc-converted pregnenolone in mitochondria, and 3β-HSD-synthesized progesterone in the smooth endoplasmic reticulum. Estrogen secretion is also stimulated by kisspeptin and regulated by gonadotropin-releasing hormone, follicle-stimulating hormone, and luteinizing hormone. Moreover, the formation of the corpus luteum is closely regulated by angiogenesis. VEGF is an important factor in angiogenesis and plays a role in the survival, proliferation, and migration of endothelial cells. Especially, VEGF–A is a key factor in the physiological functions of endothelial cells. VEGF binds VEGFR–2 and affects the signaling pathways of PI3K, Akt, MAPK, and ERK. Also, VEGF binds to HIF–1α, inducing VEGF secretion. Estrogen promotes the activation of HIF–1α, while the activation of mTOR and Akt stimulates VEGF secretion. Therefore, estrogen is a major reproductive hormone in physiological function and the synthesis and secretion of endocrine hormones in the ovary and corpus luteum.
        4,000원
        5.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aimed to develop a transportation-energy linkage model and performance evaluation indicators to improve the sustainability operation and technology of smart city transportation-energy services. METHODS : This study derived a new transportation-energy linkage system model for 15 services designated by the national pilot city. Evaluation indicators for energy-oriented transportation services in smart cities were selected, and a methodological framework was proposed for selecting quantitative evaluation indicators based on text mining and importance-performance analysis (IPA). RESULTS : Twenty indicators, confirmed as crucial for successful transportation-energy linkage in smart cities, were selected. These covered data linkage between services, IoT-based information linkage driving rate, and network and energy efficiency indicators. The proposed quantitative methodological framework can complement expert subjective evaluation by identifying meaningful implications in research literature that experts may have missed. The methodology can consistently derive indicators even when new services are added, aiding policymakers’ decisions. CONCLUSIONS : The methodological framework can contribute to minimizing operational risks in smart city transportation-energy expansion. It can also be used to prioritize service investment in smart cities by estimating benefit effects through quantitative indicators.
        4,000원
        6.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Children with cerebral palsy face challenges in maintaining body stability because of structural and functional defects. Their ability for responsive balance control is diminished. While there exist various trunk stabilization exercises such as Kinetic Link training (KLT) and the Bird-dog posture, there is a notable dearth of research that applies KLT specifically to children with cerebral palsy. Objectives: To investigate the effects of KLT and Bird-dog exercise on gross motor function and balance in children with cerebral palsy. Design: Quaxi-experimental study. Methods: The study participants were randomly divided into two groups: 15 individuals in the KLT group and 15 in the Bird-dog group. General characteristics were examined, and initial measurements of Gross motor function measure (GMFM) and Pediatric balance scale (PBS) were taken prior to the intervention. Each group engaged in KLT exercises and Bird-dog exercises for 20 minutes, three times a week over an 8 week period. Following the completion of the 8 week intervention, secondary measurements of GMFM and PBS were conducted. Results: In the KLT group, both PBS and GMFM showed a significant increase after the intervention compared to before (P<.05). Similarly, in the Bird-dog group, both PBS and GMFM significantly increased after the intervention compared to before (P<.05). There was a significant difference observed in PBS when comparing the pre- and post-intervention changes between the two groups (P<.05), whereas no significant difference was found in GMFM between the groups when comparing the pre- and post-intervention changes (P>.05). Conclusion: The interventions involving KLT and Bird-dog exercises were observed to effectively enhance PBS and GMFM in children with cerebral palsy. Specifically, it was evident that KLT was more beneficial in improving balance abilities compared to Bird-dog exercise.
        4,000원
        7.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Taguchi method is one of the most popular approaches for design optimization such that performance characteristics become robust to uncontrollable noise variables. However, most previous Taguchi method applications have addressed a single-characteristic problem. Problems with multiple characteristics are more common in practice. The multi-criteria decision making(MCDM) problem is to select the optimal one among multiple alternatives by integrating a number of criteria that may conflict with each other. Representative MCDM methods include TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution), GRA(Grey Relational Analysis), PCA(Principal Component Analysis), fuzzy logic system, and so on. Therefore, numerous approaches have been conducted to deal with the multi-characteristic design problem by combining original Taguchi method and MCDM methods. In the MCDM problem, multiple criteria generally have different measurement units, which means that there may be a large difference in the physical value of the criteria and ultimately makes it difficult to integrate the measurements for the criteria. Therefore, the normalization technique is usually utilized to convert different units of criteria into one identical unit. There are four normalization techniques commonly used in MCDM problems, including vector normalization, linear scale transformation( max-min, max, or sum). However, the normalization techniques have several shortcomings and do not adequately incorporate the practical matters. For example, if certain alternative has maximum value of data for certain criterion, this alternative is considered as the solution in original process. However, if the maximum value of data does not satisfy the required degree of fulfillment of designer or customer, the alternative may not be considered as the solution. To solve this problem, this paper employs the desirability function that has been proposed in our previous research. The desirability function uses upper limit and lower limit in normalization process. The threshold points for establishing upper or lower limits let us know what degree of fulfillment of designer or customer is. This paper proposes a new design optimization technique for multi-characteristic design problem by integrating the Taguchi method and our desirability functions. Finally, the proposed technique is able to obtain the optimal solution that is robust to multi-characteristic performances.
        4,000원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sucralose는 식품 분야에서 sucrose 대체물로 사용되며 세계적으로 승인된 무열량 고강도 인 공 감미료이다. 하지만 감미료가 뇌에 미치는 영향에 대한 조사는 미비하여 본 연구에서 scopolamine으 로 유발된 기억력 손상 동물모델에서 sucralose 단기 섭취가 인지 및 기억 보호 효과를 가지는지 확인하 였다. Sucralose 2, 5, 10 mg/kg를 경구투여하였으며 30분 후 대조군, 약물군에 scopolamine (1mg/kg) 복강투여를 진행하였고 정상군에는 식염수로 복강투여 후 행동실험을 수행하였다. 결과적으로 Y-maze, passive avoidance, Morris water maze에서 대조군과 비교해 10% 이상의 인지기능이 회복되는 결과를 도출하였다. 또한, 전염증성 사이토카인을 측정한 결과 sucralose가 IL-6와 TNF-α를 30% 이상 억제 하는 것을 보였으며 세포 내 신호 메커니즘으로 ERK-CREB의 발현량을 관찰한 결과 농도 의존적으로 증가하였다. 따라서 sucralose는 건망증 환자의 예방과 치료를 위한 기능성 식품과 관련이 있다고 시사 된다.
        4,500원
        9.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 본 연구는 농업에 종사하는 노인 여성을 대상으로 신체적 여가활동 참여가 신체적 기능 향상과 삶의 질 변화에 미치는 효과에 대해서 알아보고자 하였다. 연구방법: 농촌 지역에 거주하는 113명의 노인 여성을 대상으로 단일집단 사전-사후 검사 설계를 사용하여 연구를 진행하였다. 스트레칭, 근력 강화 및 마사지 등으로 구성된 신체적 여가활동 프로그램은 8주간 총 16회, 그룹활동으로 진행되었다. 참여 후의 노인의 신체 기능의 변화를 알아보기 위하여 근력, 유연성, 균형능력을 측정하였고, Short Form 8-Item (SF-8)을 사용하여 삶의 질의 변화를 살펴보았다. 결과: 프로그램 참여자들의 신체 기능은 상지 근력(악력), 하지 근력(30초간 앉았다 일어서기), 정적 균형(눈 뜨고 한발 서기), 동적 균형(기능적 도달) 및 유연성(등 뒤로 양손 닿기, 앉아서 윗몸 앞으로 굽히기) 항목에서 모두 유의하게 증가하였다(p < 0.05). 프로그램에 참여한 노인 여성의 건강관련 삶의 질(SF-8) 총점도 335.73 ± 52.93점에서 395.42 ± 28.79점으로 향상되었고, 모든 하위 항목에서 유의하게 변화하였다(p < 0.05). 결론: 여가활동 참여는 노인의 신체 건강뿐만 아니라 삶의 질 향상에도 효과적임을 확인할 수 있었다. 향후에는 농촌 지역 특성에 맞는 다양한 참여형 활동 프로그램의 개발과 지원이 이루어지기를 기대해 본다.
        4,600원
        10.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 본 연구는 가정방문 개별 작업중심회상치료와 센터기반 개별 작업중심회상치료가 지역사회 경증치매노인 의 인지기능과 일상생활활동에 미치는 영향을 비교하여 알아보고자 하였다. 연구방법: 본 연구는 무작위 대조군 사전-사후 설계(randomized control group pretest-posttest design)를 적용하여 충청지역의 치매안심센터에 등록된 지역사회 거주 경증치매노인 10명을 대상으로 실험군 5명, 대조군 5명으로 배정하였다. 실험군은 가정방문 개별 작업중심회상치료, 대조군은 센터기반 개별 작업중심회상 치료를 실시하였으며, 각 중재는 총 10회기로 주 1회, 회기당 60분으로 구성되었다. 평가도구는 인지기능 평가를 위한 알렌인지수준판별검사(Allen Cognitive Level Screen, ACLS)와 일상생활활동을 평가하기 위한 노인일상활동평가-복합(Seoul-Instrumental Activities of Daily Living, S-IADL)을 사용하였다. 결과: 집단 내 전후 비교량 비교 시 ACLS는 실험군에서만 점수의 차이가 유의미하였고(p < 0.05), S-IADL은 실험군과 대조군 모두 유의미한 차이를 보였다(p < 0.05). 집단 간 변화량 비교 시 ACLS는 집단 간 차이가 유의미하였고(p < 0.05), S-IADL에서는 유의미하지 않았다(p > 0.05). 결론: 본 연구에서는 지역사회 거주 경증치매노인을 대상으로 가정방문 개별 작업중심회상치료를 적용하여 인지기능 향상에 대한 단기적인 효과를 확인하였다. 본 예비연구는 국내에서 앞으로 시행될 가정방문 인지프로 그램의 근거와 방향성을 제시하였다는 측면에서 임상적인 의미가 있다.
        4,600원
        14.
        2023.11 구독 인증기관·개인회원 무료
        According to the second high-level radioactive waste management national basic plan announced in December 2021, the reference geological disposal concept for spent nuclear fuels (SNF) in Korea followed the Finnish concept based on KBS-3 type. Also, the basic plan required consideration of the development of the technical alternatives. Accordingly, Korea Atomic Energy Research Institute is conducting analyses of various alternative disposal concepts for spent nuclear fuels and is in the final selection stage of an alternative disposal concept. 10 disposal concepts including reference concept were considered for analysis in terms of disposal efficiency and safety. They were reference concept, mined deep borehole matrix, sub-seabed disposal, deep borehole disposal, multi-level disposal, space disposal, sub-sea bed disposal, long-term storage, deep horizontal borehole disposal, and ice-sheet disposal. Among them, first 4 concepts, mined deep borehole matrix, sub-seabed disposal, deep borehole disposal, multi-level disposal, were selected as candidate alternative disposal concepts by the evaluation of qualitative items. And then, by the evaluation of quantitative and qualitative items with specialists, multi-level disposal concept was being selected as a final alternative disposal concept. Design basis and performance requirements for designing alternative disposal systems were laid in the previous stage. Based on this, the design strategy and main design requirements were derived, and the engineered barrier system of a high-efficiency disposal concept was preliminary designed accordingly. In addition, as an alternative disposal concept, performance targets and related requirements were established to ensure that the high-efficiency repository system and its engineered barrier system components, such as disposal containers, buffer bentonites, and backfill perform the safety functions. Items that qualitatively describe safety functions, performance goals, and related requirements at this stage and items whose quantitative values are changed according to future test results will be determined and updated in the process of finalizing and specifically designing an alternative highefficiency disposal system.
        15.
        2023.10 구독 인증기관·개인회원 무료
        Insect cuticle is an extracellular matrix formed primarily from two different biopolymers, chitin and protein. During each molt cycle, a new cuticle is deposited simultaneously with degradation of the old cuticle by molting fluid cuticle degrading-enzymes, including epidermal chitinases (CHTs). Insect CHTs, belonging to family 18 glycosylhydrolase (GH18), have been classified into at least eleven subgroups based on phylogenetic analyses, and group I (CHT5) and group II (CHT10) epidermal CHTs present in molting fluid. In this study we report the physiological function of MaCHT5 and MaCHT10 in the Japanese pine sawyer, Monochamus alternatus. RNAi for either MaCHT5 or MaCHT10 resulted in larval-pupal and pupal-adult molting defects, in which the insects were unable to shed completely their old cuticle and died entrapped in their exuviae. Furthermore, TEM analysis revealed a failure of degradation of the old cuticle in both MaCHT5- and MaCHT10-deficient pharate adults. In the old pupal cuticle, the chitinous horizontal laminar and vertical pore canal essentially remained intact in the endocuticular layer. These results indicate that both CHTs are required for turnover of the chitinous old cuticle, which is critical for completion of insect molting. We also discuss the possible function of two spliced variants of MaCHT10, MaCHT10a and MaCHT10b.
        16.
        2023.10 구독 인증기관·개인회원 무료
        Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of glycosidic bonds in crystalline polysaccharides including chitin and cellulose. The recent discovery of LPMO family proteins in many insect species suggests that they presumably play a role in chitin degradation in the cuticle/exoskeleton, tracheae and peritrophic matrix during insect development. Insect LPMOs belong to auxiliary activity family 15 (AA15/LPMO15) and have been classified into at least four groups based on phylogenetic analysis. In this study, we identified, characterized and investigated the physiological functions of group I LPMO15 (MaLPMO15-1 and PhLPMO15-1) in two longhorn beetle species, Monochamus alternatus and Psacothea hilaris. In both species, depletion of LPMO15-1 transcripts in last instar larvae by RNAi had no effect on subsequent larval-pupal molting and the resulting pupae developed normally. However, adverse effects on their development were observed during the pupal-adult molting period. The pharate adults were unable to shed their old pupal cuticle and died entrapped in their exuviae probably due to a failure of degradation of the chitin in their old cuticle, which is critical for completion of the insect molting and continuous growth.
        17.
        2023.10 구독 인증기관·개인회원 무료
        Insect eggshell and cuticle/exoskeleton play vital roles in protecting them from natural environmental stresses. However, these chitinous cuticular extracellular matrices must be degraded at least in part during embryo hatching and molting/ecdysis periods to accommodate continuous growth all the way to the adult stage. In this study, we investigated the functional importance of groups I and II chitinases, TcCHT5 and TcCHT10, in the turnover of chitinous cuticle during both embryonic and post-embryonic development in Tribolium castaneum. RNAi and TEM analyses revealed that TcCHT10 is required for digestion of chitin in the serosal cuticle for embryo hatching as well as in the old cuticle during post-embryonic molts including larval-pupal and pupal-adult metamorphosis. TcCHT10 appears to be able to substitute for TcCHT5 in all these vital physiological events except for the pupal-adult molting in which TcCHT5 is indispensable for complete digestion of chitin in the old pupal cuticle.
        19.
        2023.10 구독 인증기관·개인회원 무료
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