• 한국패류학회지
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• 제22권1호
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• pp.39-49
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• 2006

Ultrastructure of germ cell differentiation during supermatogenesis and the reproductive cycle in male Patinopecten yessoensis was studied by histological and cytological observations. The gonadosomatic index (GSI) in males rapidly increased and reached a maximum in April when seawater temperature gradually increased. Then the GSI gradually decreased from May through July when spawning occurred. Accordingly, monthly changes in the GSI in males coincided with testicular maturation and spawning periods. The sperm morphology of P. yessoensis belongs to the primitive type and showed general characteristics of external fertilization species. The head of the spermatozoon is approximately $3.50{\mu}m$ in length: the sperm nucleus and acrosome are approximately $2.90{\mu}m\;and\;0.60{\mu}m$ in length, respectively. The nuclear type of the spermatozoon is vase in shape, and the acrosome is cone type. The axoneme of the tail flagellum consists of nine pairs of microtubules at the periphery and a pair of central microtubules in the center The satellite body (which is formed by the centriole) and four mitochondria appear in the middle piece of the spermatozoon. The spawning period was from April through July and the main spawning occurred from May to June when seawater temperatures gradually increased. The reproductive cycle of this species can be classified into five successive stages; early active stage (September to November), late active stage (October to March), ripe stage (February to August), spawning stage (April to July), and spent/inactive stage (July to November).

• PNF and Movement
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• 제13권3호
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• pp.135-143
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• 2015

Purpose: The purpose of this study was to assess the effect of the proprioceptive neuromuscular facilitation (PNF) relaxation technique (hold relax; HR, contract relax; CR) and static stretch (SS) on hamstring flexibility and vertical jump performance in healthy adults over a four-week period. Methods: Twenty-four healthy adults volunteered to participate in PNF and static stretch sessions. The subjects were divided into three groups as follows: 8 subjects in the SS group, 8 subjects in the HR group, and 8 subjects in the CR group. In the HR and CR groups, contractions lasted 15 seconds per trial and consisted of 5 sets of 15 seconds of hamstring contraction immediately followed by 15 seconds of passive static hamstring stretching. For the static group, the participants were asked to stretch by hanging a leg over a table for 30 seconds. Subjects in all groups performed the exercises three days per week for 4 weeks. The active straight leg raising (ASLR) test, active knee extension (AKE) test, and vertical jump test were performed before the intervention and after 1, 2, and 4 weeks. Results: The SS, HR, and CR techniques effected positive improvement in hamstring flexibility and vertical jump performances but neither of the stretching methods had any statistically significant different effects according to group, although there were interactions (between group and time) in the ALSR group from 1 week to 2 week and in the AKE test from pretest to 1 week. Conclusion: Based on the results of the current study, SS, HR, and CR were shown to affect hamstring flexibility and vertical jump performance in healthy adults. In particular, it was determined that within a short period, hamstring flexibility could be attributed more to CR than to SS.

• Ocean Systems Engineering
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• 제8권4호
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• pp.427-439
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• 2018

Floating Production Storage and Offloading (FPSO) units have the advantages of their ability to provide storage and offloading capabilities which are not available in other types of floating production systems. In addition, FPSOs also provide a large deck area and substantial topsides payload capacity. They are in use in a variety of water depths and environments around the world. It is a good solution for offshore oil and gas development in fields where there is lack of an export pipeline system to shore. However due to their inherently high motions in waves, they are limited in the types of risers they can host. The Low Motion FPSO (LM-FPSO) is a novel design that is developed to maintain the advantages of the conventional FPSOs while offering significantly lower motion responses. The LM-FPSO design generally consists of a box-shape hull with large storage capacity, a free-hanging solid ballast tank (SBT) located certain distance below the hull keel, a few groups of tendons arranged to connect the SBT to the hull, a mooring system for station keeping, and a riser system. The addition of SBT to the floater results in a significant increase in heave, roll and pitch natural periods, mainly through the mass and added mass of the SBT, which significantly reduces motions in the wave frequency range. Model tests were performed at the Korea Research Institute of Ships & Ocean Engineering (KRISO) in the fall of 2016. An analytical model of the basin model (MOM) was created in Orcaflex and calibrated against the basin-model. Good agreement is achieved between global performance results from MOM's predictions and basin model measurements. The model test measurements have further verified the superior motion response of LM-FPSO. In this paper, numerical results are presented to demonstrate the comparison and correlation of the MOM results with model test measurements. The verification of the superior motion response through model test measurements is also presented in this paper.

• 대한건축학회논문집:계획계
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• 제36권5호
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• pp.41-51
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• 2020

As there are the elderly who have difficulty in evacuating themselves, it is necessary to develop architectural and institutional planning for nursing homes that can minimize disaster damage. The purpose of this study was to suggest the improvement plan by grasping the current status of nursing homes on planning aspects such as floor plan type, spatial layout, and evacuation route through 14 case studies in Cheongju city in terms of disaster safety. The results of this study were as follows; the most common plan type was the grouped-corridor type difficulty in securing evacuation routes. The circulation corridor type is need to be considered because it is possible not only to secure evacuation and nursing routes, but also to create a hanging around corridor for the elderly with dementia. Second, if there is a risk of flooding due to the location, the living room should be placed on the 2nd floor or more. In particular, a kitchen should be placed not adjacent to the entrance and the vertical evacuation route. Third, the horizontal evacuation route should be arranged differently depending on the floor plan type. For vertical evacuation routes, it is necessary to install outdoor stairs or ramps considering the evacuation characteristics of the elderly. In addition, the institutional aspects should be considered to ensure the safety of disasters.

• 복식문화연구
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• 제29권1호
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• pp.103-120
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• 2021

This study interprets Siberian shaman costumes from the perspective of Siberian shamanism's spiritual culture by combining theoretical and empirical studies. According to the natural environment and language families, the Siberian people are classified into the Altai, Tungus, Ural, and Paleo-Siberian groups. Se Yin's research classifies the spiritual culture of Siberian shamanism as cosmic, spiritual, and nature view. Eliade's research has divided Siberian shaman costumes into form, headdress, and ornament. According to the present study, shaman costume form and decoration reflect the Siberian three-tiered cosmic view, such that the shaman's head, body and feet correspond to the upperworld, middleworld and underworld. In addition, animism, totemism and ancestral worship appear in the shamanism's spiritual view. For example, the costume's form shows the totem of each tribe, while the costume accessories reflect animal worship, plant worship and ancestral worship. Finally, shamanism's nature view mainly manifests through three processes: personification, deification, and ethics. As an intermediary between man and the spirits, shaman use their clothing to reproduce the image of half man and half spirit. The shaman's costumes are deified and considered to have divine power. For example, the animals represented on the costume help the shaman travel through space. Generally, good animals help a shaman enter the upperworld, while animals that help a shaman enter the underworld are considered evil. Also, the number of hanging accessories represents the shaman's ability.

• Journal of Ginseng Research
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• 제46권5호
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• pp.657-665
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• 2022

Background: Sarcopenia is a new and emerging risk factor aggravating the quality of life of elderly population. Because Korean Red Ginseng (RG) is known to have a great effect on relieving fatigue and enhancing physical performance, it is invaluable to examine its potential as an anti-sarcopenic drug. Methods: Anti-sarcopenic effect of non-saponin fraction of Korean Red Ginseng (RGNS) was evaluated in C2C12 myoblasts treated with C2-ceramide to induce senescence phenotypes, and 22-month-old mice fed with chow diet containing 2% RGNS (w/w) for 4 further months. Results: The RGNS treatment significantly alleviated cellular senescence indicated by intracellular lipid accumulation, increased amount of lysosomal β-galactosidase, and reduced proliferative capacity in C2C12 myoblasts. This effect was not observed with saponin fraction. In an aged mouse, the 4-month-RGNS diet significantly improved aging-associated loss of muscle mass and strength, assessed by the weights of hindlimb skeletal muscles such as tibialis anterior (TA), extensor digitorum longus (EDL), gastrocnemius (GN) and soleus (SOL), and the cross-sectional area (CSA) of SOL muscle, and the behaviors in grip strength and hanging wire tests, respectively. During the same period, an aging-associated shift of fast-to slow-twitch muscle in SOL muscle was also retarded by the RGNS treatment. Conclusions: These findings suggested that the long-term diet of RGNS significantly prevented aging-associated muscle atrophy and reduced physical performance, and thus RGNS has a strong potential to be developed as a drug that prevents or improves sarcopenia.

• Structural Engineering and Mechanics
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• 제80권6호
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• pp.749-765
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• 2021

Suspension bridges bear large eccentric live loads in rush hours when most vehicles travel in one direction on the left or right side of the bridge. With the increasing number and weight of vehicles and the girder widening, the eccentric live load effect on the bridge behavior, including bending and distortion of the main girder, gets more pronounced, even jeopardizing bridge safety. This study proposes an analytical algorithm based on multi-catenary theory for predicting the suspension bridge responses to eccentric live load via the nonlinear generalized reduced gradient method. A set of governing equations is derived to solve the following unknown values: the girder rigid-body displacement in the longitudinal direction; the horizontal projection lengths of main cable's segments; the parameters of catenary equations and horizontal forces of the side span cable segments and the leftmost segments of middle span cables; the suspender tensions and the bearing reactions. Then girder's responses, including rigid-body displacement in the longitudinal direction, deflections, and torsion angles; suspenders' responses, including the suspender tensions and the hanging point displacements; main cables' responses, including the horizontal forces of each segment; and the longitudinal displacement of the pylons' tower top under eccentric load can be calculated. The response of an exemplar suspension bridge with three spans of 168, 548, and 168 m is calculated by the proposed analytical method and the finite element method in two eccentric live load cases, and their results prove the former's feasibility. The nonuniform distribution of the live load in the lateral direction is shown to impose a greater threat to suspension bridge safety than that in the longitudinal direction, while some other specific features revealed by the proposed method are discussed in detail.

• 대한본초학회지
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• 제32권4호
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• pp.47-52
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• 2017

Objective : Phellinus spp. mushroom is an object of interest because it has excellent anticancer effect. Owing to the similalarities in the morphology, Phellinus linteus and Phellinus baumii are often used as same Sang Hwang Mushroom in the Korean market.. The quality control for mushrooms is needed because there are many differences in the efficacy according to cultivation method and cultivation area. Therefore, a reliable authentication method of these herbal medicine is necessary to compare and measure the amount of beta-glucan which is known to have a hypoglycemic effect, from the mushrooms collected in various regions Methods : 7 samples of medicinal mushrooms supplying phellinus spp. were collected in Korea, China and Cambodia. We investigated the hardness, colors, extract ratio, ${\alpha}-amylase$ and ${\alpha}-glucosidase$ inhibitory activities, glucose transporter 4 (GLUT-4) expressions of water extracts from Phellinus spp and also MTT assay were examined for cell toxicity. Results : The results revealed that Phellinus spp.water Ext.inhibited ${\alpha}-glucosidase$ activity. glucose transporter 4 (GLUT-4), the key insulin signaling pathway transcription factor, was remarkably increased by the Phellinus baumii water extract Conclusions : These results suggest that The more yellowish the mushroom is, the lower the hardness, the more the content of ${\beta}-glucan$ is proportional. Because the more ${\beta}-glucan$, the greater the effect of hypoglycemia. compared to the hypoglycemic effect, Phellinus Baumii grown at hanging on selves for 7 month in the green house is the best.

• 문화기술의 융합
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• 제9권1호
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• pp.525-530
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• 2023

2단 행거는 공간 활용도가 높고 설치가 쉬운 장점으로 인해 많은 가정에서 사용되고 있지만 사용 시 높이 조절이 불가능해 사용자가 상단봉에 걸려있는 옷을 내리기에 많은 어려움이 있다. 따라서 본 논문에서는 기존 2단 행거의 기능 및 장점은 유지하면서 사용자가 의류를 손쉽게 걸거나 꺼낼 수 있는 새로운 형태의 2단 행거 형상을 제안한다. 한 번의 동작으로 상단봉이 사용에 편리한 높이까지 내려올 수 있도록 적절한 링크기구를 설계하였으며 높이 조절 시 상/하단 의류가 겹치지 않도록 상/하단봉의 움직임을 입체형으로 구현하였다. 또한 상단봉이 내려올 때 행거가 넘어지지 않으면서 사용 후 고정이 해제되어 원래의 높이로 올라갈 수 있는 적절한 링크 길이와 조인트 위치 및 구속 조건을 선정하였으며 사용자의 안전을 위해 가스 스프링을 추가하여 하강 및 상승 속도를 조절하였다. 높이 조절시 옷의 하중을 지탱할 수 있도록 FEA 해석을 통해 개선 형상에 대한 안정성을 검증하였으며 실제 제작을 통해 입체형 높이 조절 행거의 작동 여부를 확인하였다.

• Geomechanics and Engineering
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• 제33권2호
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• pp.141-154
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• 2023

This study investigated the effect of water retention characteristics between aged and fresh Municipal Solid Waste (MSW) on the stability of the landfill. A series of transient numerical modeling for the slope of an MSW landfill was performed considering the variation of water retention characteristics due to leachate circulation. Four different scenarios were considered in this analysis depending on how to obtain hydraulic conductivity and the aging degree of materials. Unsaturated hydraulic properties of the MSW used for the modeling were evaluated through modified hanging column tests. Different water retention properties and various landfill conditions, such as subgrade stiffness, leachate injection frequency, and gas and leachate collection system, were considered to investigate the pore water distribution and slope stability. The stability analyses related to the factor of safety showed that unsaturated properties under those varied conditions significantly impacted the slope stability, where the factor of safety decreased, ranging between 9.4 and 22%. The aged materials resulted in a higher factor of safety than fresh materials; however, after 1000 days, the factor of safety decreased by around 10.6% due to pore pressure buildup. The analysis results indicated that using fresh materials yielded higher factor of safety values. The landfill subgrade was found to have a significant impact on the factor of safety, which resulted in an average of 34% lower factor of safety in soft subgrades. The results also revealed that a failed leachate collection system (e.g., clogging) could result in landfill failure (factor of safety < 1) after around 298 days, while the leachate recirculation frequency has no critical impact on stability. In addition, the accumulation of gas pressure within the waste body resulted in factor of safety reductions as high as 24%. It is essential to consider factors related to the unsaturated hydraulic properties in designing a landfill to prevent landfill instability.