• 한국운동역학회지
• /
• 제31권3호
• /
• pp.214-219
• /
• 2021

Objective: The aim of this study was to evaluate the differences in muscle activity of hamstring muscle depending on the position of the feet during Swiss ball hamstring curl exercise. Method: Total of 15 male participants with no history of hamstring muscle injuries and musculoskeletal disorders in the past 6 months were participated in this study (Age: 29.27 ± 4.96 yrs, Height: 173.47 ± 5.18 cm, Body mass: 75.47 ± 12.50 kg). The muscle activation of semitendinosus and biceps femoris with four different feet positions including neutral stance, internal rotation, external rotation, and wide stance were measured during a Swiss ball hamstring curl exercise. For the analysis, the Swiss ball exercise movement comprised of 3 events (90°→ 0°→ 90°) based on the knee angle and 2 phases relative to the mechanism of muscle contraction (eccentric/concentric contraction). To pursue the study goal, an one-way ANOVA with repeated measures was performed with statistical significance as α = 0.05. Results: There was no statistically significant feet position effect found during the Swiss ball hamstring curl with eccentric contraction phase (p>.05). It is, however, semitendinosus showed an enhanced muscle activation in concentric contraction phase, displaying the highest muscle activity in wide stance and the lowest in external rotation (p<.05). Conclusion: Our findings suggest that this exercise can be beneficial in selectively training the semitendinosus. In other words, Swiss ball hamstring curls performed in wide stance strengthens semitendinosus, which improves the stability of knee and are effective in preventing knee injuries and reinforces rehabilitation.

• 대한토목학회논문집
• /
• 제43권3호
• /
• pp.363-370
• /
• 2023

COVID-19 (Coronavirus disease 2019) 확산으로 2020년 초부터 도시철도 등 대중교통수단의 이용량이 크게 변동하였다. 이에 본 연구에서는 COVID-19 이전과 COVID-19 확산 이후, 3년 동안 도시철도 역별 일별 시계열 자료를 수집하여 DTW (Dynamic Time Warping) 거리법을 통해 시계열 군집분석 유사도를 평가하여 군집 별 회귀 중앙치를 도출하고, COVID-19 등 여러 외부 사건이 이용객 수의 변동에 미치는 영향을 시계열 충격 탐지 함수(Outlier Detection)로 진단하였다. 또한 도시철도 역의 군집 별 이용 특성을 분석하고 또한 외부 충격에 따른 승객량의 변동을 파악하였다. 향후 COVID-19 재확산 시 이용량의 유지와 회복에 대한 방안을 검토하는 데 목적을 두었다.

• IMMUNE NETWORK
• /
• 제23권1호
• /
• pp.3.1-3.14
• /
• 2023

Microvilli are outer membrane organelles that contain cross-linked filamentous actin. Unlike well-characterized epithelial microvilli, T-cell microvilli are dynamic similar to those of filopodia, which grow and shrink intermittently via the alternate actin-assembly and -disassembly. T-cell microvilli are specialized for sensing Ags on the surface of Ag-presenting cells (APCs). Thus, these finger-shaped microprotrusions contain many signaling-related proteins and can serve as a signaling platforms that induce intracellular signals. However, they are not limited to sensing external information but can provide sites for parts of the cell-body to tear away from the cell. Cells are known to produce many types of extracellular vesicles (EVs), such as exosomes, microvesicles, and membrane particles. T cells also produce EVs, but little is known about under what conditions T cells generate EVs and which types of EVs are released. We discovered that T cells produce few exosomes but release large amounsts of microvilli-derived particles during physical interaction with APCs. Although much is unanswered as to why T cells use the same organelles to sense Ags or to produce EVs, these events can significantly affect T cell fate, including clonal expansion and death. Since TCRs are localized at microvilli tips, this membrane event also raises a new question regarding long-standing paradigm in T cell biology; i.e., surface TCR downmodulation following T cell activation. Since T-cell microvilli particles carry T-cell message to their cognate partner, these particles are termed T-cell immunological synaptosomes (TISs). We discuss the potential physiological role of TISs and their application to immunotherapies.

• 한국콘텐츠학회논문지
• /
• 제15권1호
• /
• pp.357-365
• /
• 2015

민간요법 유해사례란 예로부터 민간에 전해 내려오는 질병 치료법인 민간요법 사용 중에 발생되는 바람직하지 않거나 의도되지 않은 모든 불편감이다. 본 연구는 인터넷 뉴스기사를 통해 민간요법 유해사례의 형태와 위험성을 분석하고자 하였다. 인터넷트렌드(www.internettrend.co.kr)의 웹사이트 분석평가에 의한 점유율 상위 3개 포털 사이트인 네이버(NAVER), 다음(DAUM), 네이트(NATE)를 검색 대상으로 선정하여 최근 5년간(2009년 1월 1일부터 2014년 2월 28일까지) 민간요법 유해사례의 신문기사를 검색하였다. 총 973건의 신문기사가 검색되었고 18건이 포함기준에 만족되었다. 유해사례를 경험한 사람은 총 27명으로 연령은 4개월부터 76세까지이고, 남녀 모두에게 발생하였다. 2회 이상 반복적인 유해사례를 일으킨 민간요법으로는 독성 약재인 봉삼 또는 초오를 재료로 사용하여 복용한 요법, 피부에 외용하는 식초요법, 시술자에 의한 벌침 또는 부항요법이었다. 중대한 유해사례로서 사망이 11명이 있었으며 자신이 직접 복용한 1명을 제외하고는 모두 의료인이 아닌 무자격자의 시술에 의한 사망이었다. 국내에서 대중적인 민간요법은 인터넷 상에서 정보가 활발히 상호 교류되며 전문 의료인의 지도 없이 오, 남용되고 있는 것이 현실이다. 국민의 보건의료측면에서 국가나 의료계가 민간요법 유해사례에 대한 위험성 홍보 및 올바른 건강정보 제공 계획을 세우고 나아가 유해사례를 보고 및 감시하는 체계도 확립해야 할 필요성이 있음을 지적하는 바이다.

• 응용통계연구
• /
• 제22권2호
• /
• pp.249-260
• /
• 2009

정책수단과 장래 발생할 사건 간에 시차가 존재할 때 미래의 상태를 예측하는 데 유용한 선행지표의 개발에 다양한 방법들이 모색되어 왔다. 미래의 상황전개에 대응하는데 필요한 정보가 조기에 제공된다면 최근과 같은 경제위기의 폭은 크게 감소될 수 있을 것이다. 그간 금융환경이 변화하면서 금융변수와 실물경제활동 간에 관계가불안정해지고 괴리가 심화됨에 따라 본 연구에서는 미래의 경기동향을 미리 예측할 수 있는 국내외 금리변수들의 예측 능력을 추정해 비교 평가해 보았다.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제14권2호
• /
• pp.91-97
• /
• 2014

Chaotic dynamics is an active research area in fields such as biology, physics, sociology, psychology, physiology, and engineering. Interest in chaos is also expanding to the social sciences, such as politics, economics, and societal events prediction. Most people pursue happiness, both spiritual and physical in many cases. However, happiness is not easy to define, because people differ in how they perceive it. Happiness can exist in mind and body. Therefore, we need to be happy in both simultaneously to achieve optimal happiness. To do this, we need to synchronize mind and body. In this paper, we propose a chaotic synchronization method in a mathematical model of happiness organized by a second-order ordinary differential equation with external force. This proposed mathematical happiness equation is similar to Duffing's equation, because it is derived from that equation. We introduce synchronization method from our mathematical happiness model by using the derived Duffing equation. To achieve chaotic synchronization between the human mind and body, we apply an idea of mind/body unity originating in Oriental philosophy. Of many chaotic synchronization methods, we use only coupled synchronization, because this method is closest to representing mind/body unity. Typically, coupled synchronization can be applied only to non-autonomous systems, such as a modified Duffing system. We represent the result of synchronization using a differential time series mind/body model.

• 수산경영론집
• /
• 제31권1호
• /
• pp.1-12
• /
• 2000

The experience of many countries strongly suggests that bad governments and institutions have been a serious, if not the most serious, obstacle to economic growth and industry-structural adjustments. All public sectors pursue a mix of both predatory and productive activities-bad governments emphasizing the former, while good governments finding a way of promoting the later. In fishery public policy studies, much confusion exists about the roles of policy illustration and prescription. In general fishery public sectors involve collective actions by numerous individuals under conditions of uncertainty, complexity, bounded rationality, and imperfect information structure. All collective fisheries action organizations consist of a center(e.g., government), which leads fishery group actions, and peripheral participants(e.g., fishermen), which are controlled by the government. A paradigm is developed that gives both theoretical and empirical meaning to the constitutional determination of fisheries political preference function or fishery public sector governance structures. Three relevant spaces are specified: policy instrument, results, and constitutional. The collective-choice rules of the constitutional space structure the tradeoff between public and special fishery interest groups. Fishery public sectors seeking sustainable reductions in wasteful rent-seeking fishing activities should select constitutional principles and institutional structures that tend to promote resource sustainability. In particular, the effects of internal and external events on fisheries may result in a greater or lesser concentration of interest group power. Thus, the structure of the fishereis political power must be assessed in any prescriptive evaluation of alternative fishery governance weights.

• Nuclear Engineering and Technology
• /
• 제49권7호
• /
• pp.1431-1441
• /
• 2017

The Fukushima accident reveals the vulnerability of existing active nuclear power plant (NPP) design against prolonged loss of external electricity events. The passive safety system is considered an attractive alternative to cope with this kind of disaster. Also, the passive safety system enhances both the safety and the economics of NPPs. The adoption of a passive safety system reduces the number of active components and can minimize the construction cost of NPPs. In this paper, reflecting on the experience during the development of the APR+ design in Korea, we propose the concept of an innovative Power Reactor (iPower), which is a kind of passive NPP, to enhance safety in a revolutionary manner. The ultimate goal of iPower is to confirm the feasibility of practically eliminating radioactive material release to the environment in all accident conditions. The representative safety grade passive system includes a passive emergency core cooling system, a passive containment cooling system, and a passive auxiliary feedwater system. Preliminary analysis results show that these concepts are feasible with respect to preventing and/or mitigating the consequences of design base accidents and severe accidents.

• 생명과학회지
• /
• 제11권4호
• /
• pp.362-370
• /
• 2001

Regulation of cell proliferation is a complex process involving the regulated expression and /or modification of discrete gene products. which control transition between different stages of the cycle. The purpose of this short review is to provide an overview of somatic cell cycle events and their controls. Cycline have appeared as major positive regulators in this network, because their association to the cyclin-dependent kinases(Cdks) allows the subsequent activation on the Cdk/cyclin complexes and their catalatic activity. In mammalian cells, early to mid G1 progression and late G1 progression leading to S phase entry are directed by D-type cyclins-Cdk4, 6 and cyclin E-Cdk 2 both of which can phosphorylate the retinoblastoma protein (pRB). pRB is a transcriptional repressor which, in its unphosphorylated state, binds to members of the E2F transcription factor family and blocks E2F-dependent transcription of genes controlling the G1 to S phase transition an subsequent DNA synthesis. Cyclin A is produced in late G1 and expressed during S and G2 phae, and expression of B-type cyclins is typically maximal during the G2 to M phase transition and it controls the passage through M phase. They primarily associate with the activate Cdk2, and Cdc2, respectively. On the other hand, the Cdk inhibitors negatively control the activity of C아/cyclin complex by coordinating internal and/or external signals and impending proliferation at several key checkpoints. These current and further findings will provide novel approaches to understanding and treating major diseases.

• 환경생물
• /
• 제22권2호
• /
• pp.300-307
• /
• 2004

The chloroacetanilide herbicide alachlor (2-chloro-2', 6'-diethyl-N-(methoxymethyl)-acetanilide) and organochlorine insecticide endosulfan (6, 7, 8, 9, 10, 10-hexachloro-l, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 3, 4-benzodioxathiepin-3-oxide)are the highly toxic agricultural chemicals. Bombina orientalis is one of the most common amphibians in the world and comprises a large proportion of their total number. B. orientalis spawns in the farming regions at Spring when the massive application of agricultural chemicals occurs. These chemicals in farmland may threaten the reproduction of this frog. Therefore, we examined the embryotoxic and survival effects of alachlor and endosulfan at various concentrations in B. orientalis embryos. The survival rates of embryos at 312h post fertilization treated with alachlor and endosulfan were decreased with concentration dependent manner. Also, developmental malformations appeared by alachlor and endosulfan in B. orientalis embryos. The malformations showed in order of frequency with bent trunk, tail dysplasia, bent tail, thick-set body and ventral blister in alachlor treated embryos. The exposure of endosulfan produced 7 types of severe external malformations with tail dysplasia, pectoral blister, bent trunk, bent tail, cephalic dysplasia, ventral blister, and thick-set body. Following exposure to alachlor and endosulfan the types of malformations were diverse, suggesting these chemicals target multiple events in embryonic and larval development in this species. These results suggested that alachlor and endosulfan were detrimental for survival and development of B. orientalis embryos.