• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.214-219
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• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.3
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• pp.363-370
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• 2023

Due to the spread of COVID-19, the use of public transportation such as urban railroads has changed significantly since the beginning of 2020. Therefore, in this study, daily time series data for each urban railway station were collected for three years before COVID-19 and after the spread of COVID-19, and the similarity of time series analysis was evaluated through DTW (Dynamic Time Warping) distance method to derive regression centers for each cluster, and the effect of various external events such as COVID-19 on changes in the number of users was diagnosed as a time series impact detection function. In addition, the characteristics of use by cluster of urban railway stations were analyzed, and the change in passenger volume due to external shocks was identified. The purpose was to review measures for the maintenance and recovery of usage in the event of re-proliferation of COVID-19.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.3.1-3.14
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• 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.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.357-365
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• 2015

Folk medicine is traditionally passed down to cure disease, and adverse events (AEs) of folk medicine are any unfavorable and unintended discomforts temporally associated with the use of folk medicine. The aim of this study was to analyze AEs types and risks of folk medicine through the internet news articles. Included in this analysis are all articles on the topic of folk medicine and AE reported in the top 3 online news websites (NAVER, DAUM and NATE) determined by InternetTrend$^{TM}$(www.internettrend.co.kr). It was searched in the last five years (between 1 January 2009 and 28 February 2014). In total, 18 AEs articles of 973 news articles met our inclusion criteria. A total of 27 people were experienced AEs associated with use of folk medicine. Age was from 4 months to 76 years old, and it was occurred in both men and women. Folk medicine that caused AEs in twice or more was therapy that patient taking the dictamnus or aconitum of toxic herbal medicines, vinegar therapy of external use to topical skin, and cupping or bee sting therapy by practitioners. Death as a kind of serious AEs was 11 people, and 10 people were died after treatment by unqualified practitioner. Folk medicine that is popular and widely used in Korea is actively interacted with information on the internet, so it apt to misuse and abuse without guidance of health professionals. Aspects of health care system, we point out that the need for government and medical society establish not only correct health information plan and promotion of risk but also system as reporting and monitoring of AEs by folk medicine.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.249-260
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• 2009

Various methods have been suggested in developing the useful leading indicators to predict the actual realizations when time laps exist between policy plannings and future events. The recent economic crisis could have been relived if the information necessary to respond to the future evolutionary process is provided in advance. As the relations between the financial variables and the real economic activity become unstable because of the changes in the financial environment, this study attempts to estimate the capabilities of various internal and external term spreads in predicting the future business trend, followed by comparison and evaluation.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.2
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• pp.91-97
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• 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.

• The Journal of Fisheries Business Administration
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• v.31 no.1
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• pp.1-12
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• 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
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• v.49 no.7
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• pp.1431-1441
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• 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.

• Journal of Life Science
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• v.11 no.4
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• pp.362-370
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• 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.

• Korean Journal of Environmental Biology
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• v.22 no.2
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• pp.300-307
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• 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.