• The Korean Journal of Physiology
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• v.4 no.2
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• pp.19-24
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• 1970

Since the discovery of the muscle spindle by Hassall (1831), an intensive studies of its anatomical and physiological characteristics had been undertaken. Recent morphological studies of Boyd (1962) demonstrated that the muscle spindles have two different intrafusal muscle fibers, nuclear bag and nuclear chain fiber, and these intrafusal fibers are under independent motor innervation by ${\gamma}_1$ and ${\gamma}_2$ motor neurone. Neurophysiological studies of Hunt and Kuffler (1951) showed regulatory effect of ${\gamma}$ motor neurone upon the excitability of the spindle afferents. Harvey and Mathews (1961) observed the dynamic and static characteristics of the two different spindle afferents, the primary and secondary ending. Furthermore, Mathews (1962) postulated the functional existance of two kind of ${\gamma}$ motor neurones, namely, the dynamic and static fusimotor fiber. Recent report of Kim and Partridge(1969) pointed out that the descending vestibular signals had increased the slope of the length-tension relationship in stretch reflex; Kim (1967) demonstrated that the descending vestibular impulses act upon the stretch reflex loop through the ${\gamma}$ motor pathway. These experimental evidences from the morphological and neurophysiological studies on the muscle spindles support the concept that the stretch reflex action of the skeletal muscle operates as a negative feedback control system. The author had discussed the way by which the f system participates in the control of stretch relfex feed back system. that was taken for a prototype of posture and movement.

• Journal of the Korean Data and Information Science Society
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• v.22 no.5
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• pp.829-837
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• 2011

Since Harvey (1989), many approaches for applying unobserved components (UC) models to both univariate and multivariate time series analysis have been developed. However, practitioners still tend to use traditional methods such as exponential smoothing or ARIMA models for modeling and predicting time series data. It is well known that the UC model combines the flexibility of ARIMA models and the easy interpretability of exponential smoothing models by using unobserved components such as trend, cycle, season, and irregular components. This study reviews the UC model and compares its relative performances with those of the other models in modeling and predicting the real gross domestic products (GDP) in Korea. We conclude that the optimal model is the UC model on basis of root mean squared error.

• ALGAE
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• v.21 no.1
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• pp.157-160
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• 2006

Three different forms of Undaria pinnatifida, the southern form (U. pinnatifida f. typica), the northern form (U. pinnatifida f. distans), and Samcheok form (recently cultivated strain), were examined for the contents and compositions of fucoidans. Fucoidans were extracted from the dried edible portions of three forms of U. pinnatifida in low pH condition, mainly by ethanol precipitation and CaCl2 treatment. It was shown that Samcheok form contains 1.8 and 3.5 times more fucoidans than the northern and the southern forms, respectively. The monosaccharide compositions of individual fucoidans were also varied. The fucoidans from the southern and the northern forms were shown to be composed of mainly fucose and galactose with the molar percentage ratios of 83.5%:16.5% and 87.4%:12.6%, respectively, indicating that these are F-type fucoidans. The fucoidan from Samcheok form, however, consisted of fucose (62.7%), galactose (32.9%), and small amount of glucose (4.4%). The results of this study showed that both amount and monosaccharide compositions of fucoidans are variable depending on U. pinnatifida forms.

• ALGAE
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• v.30 no.4
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• pp.291-301
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• 2015

The present study described with different microscopy approaches chloroplasts lobes in Laurencia sensu latu (Rhodophyta) species and found inter-specific differences among them. Chloroplasts were investigated using confocal laser scanning microscopy (LSM), transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HRSEM). Using and TEM and HRSEM images we distinguished chloroplasts with lobes than chloroplasts without lobes in Yuzurua poiteaui var. gemmifera (Harvey) M. J. Wynne and Laurencia dendroidea J. Agardh cortical cells. The LSM images showed chloroplasts lobes (CLs) with different morphologies, varying from thicker and longer undulated projections in Y. poiteaui var. and L. dendroidea to very small and thin tubules as in Laurencia translucida Fujii & Cordeiro-Marino. The diameter and length of CLs from Y. poiteaui var. and L. dendroidea were significantly higher than L. translucida CLs (p < 0.01). Based on LSM observations, we suggest that lobes morphology has a taxonomic validity only to characterize L. translucida species.

• The Korean Journal of Mycology
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• v.14 no.3
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• pp.231-235
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• 1986

Spore production mechanism of selected lignicolous basidiomycetes was inhibited by soaking their sporocarps in water for varying periods. Depending on the duration of immersion, some species resumed spore discharge, while in others it was completely ruined. This was related to the nature and consistency of these sporocarps. All the species studied absorbed water quite readily into their sporocarps. The loss of this water through dehydration was more rapid in smaller and delicate species than the bulky and robust ones.

• Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.127-132
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• 2007

The anti-inflammatory activities of dichloromethane, ethanol, and boiling water extracts of the brown seaweeds Undaria pinnatifida (Harvey) Suringar and Laminaria japonica Areschoug were examined. Ethanol extracts (0.4 mg/ear) of U. pinnatifida inhibited inflammatory symptoms in mouse ear edema by 95.3%, and dichloromethane extract inhibited erythema by 65.5%. Dichloromethane and ethanol extracts (4 g/kg bw) of L. japonica demonstrated potent antipyretic activity. Activities of the seaweed extracts were similar to those of the commonly used drugs indomethacin and acetyl salicylic acid. No acute toxicity was observed after p.o. administration of each extract (5 g/kg bw). These results were in agreement with the claims of the health care industry and indigenous medicine that the above seaweeds can be used as an effective remedy for inflammation-related symptoms.

• Toxicological Research
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• v.32 no.1
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• pp.15-20
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• 2016

Physiologically based pharmacokinetic (PBPK) modeling can provide an effective way to utilize in vitro and in silico based information in modern risk assessment for children and other potentially sensitive populations. In this review, we describe the process of in vitro to in vivo extrapolation (IVIVE) to develop PBPK models for a chemical in different ages in order to predict the target tissue exposure at the age of concern in humans. We present our on-going studies on pyrethroids as a proof of concept to guide the readers through the IVIVE steps using the metabolism data collected either from age-specific liver donors or expressed enzymes in conjunction with enzyme ontogeny information to provide age-appropriate metabolism parameters in the PBPK model in the rat and human, respectively. The approach we present here is readily applicable to not just to other pyrethroids, but also to other environmental chemicals and drugs. Establishment of an in vitro and in silico-based evaluation strategy in conjunction with relevant exposure information in humans is of great importance in risk assessment for potentially vulnerable populations like early ages where the necessary information for decision making is limited.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.883-900
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• 2017

In this paper block based blind secure gray image watermarking scheme based on discrete wavelet transform and singular value decomposition is proposed. In devising the proposed scheme, security is given high importance along with other two requirements: robustness and imperceptibility. The use of discrete wavelet transform not only improves robustness but the selection of bands with high tolerance towards noise caused an improvement in terms of imperceptibility. The robustness further improved due to the involvement of singular vectors along with singular values in watermark embedding and extraction process. Finally, to achieve security, the selected DWT band is decomposed into smaller blocks and random blocks are chosen for modification. Furthermore, the elements of left and right singular vectors of selected blocks are chosen based on their dependence upon each other for watermark embedding. Various experiments using different images as host and watermark were conducted to examine and validate the proposed technique. Additionally, the proposed technique is tested against various attacks like compression, affine transformation, cropping, translation, X shearing, scaling, Y shearing, filtering, blurring, different kinds of noises, histogram equalization, rotation, etc. Lastly, the proposed technique is compared with state-of-the-art watermarking techniques and their comparison shows significant improvement of proposed scheme over existing techniques.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.99-101
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• 2015

Massive stars are some of the most influential objects in the Universe, shaping the evolution of galaxies, creating chemical elements and hence shaping the evolution of the Universe. However, the processes by which they form and how they shape their environment during their birth processes are not well understood. We use $NH_3$ data from "The $H_2O$ Southern Galactic Plane Survey" (HOPS) survey to define the positions of dense cores/clumps of gas in the southern Galactic plane that are likely to form stars. Then, using data from "The Millimetre Astronomy Legacy Team 90 GHz" (MALT90) survey, we search for the presence of infall and outflow associated with these cores. We subsequently use the "3D Molecular Line Radiative Transfer Code" (MOLLIE) to constrain properties of the infall and outflow, such as velocity and mass flow. The aim of the project is to determine how common infall and outflow are in star forming cores, and therefore to provide valuable constraints on the timescales and physical process involved in massive star formation. Preliminary results are presented here.

• Journal of the Korean Geographical Society
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• v.33 no.spc
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• pp.709-719
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• 1998

오늘날 세계는 물질적으로 풍요롭게 되었지만, 생태위기의 발생과 더불어 환경문데를 둘러싼 불평등이 감소하기 보다는 오히려 증대하고 있다. 21세기를 위한 새로운 패러다임으로서 생태학은 이러한 불평등을 극복하기 위한 지식 및 실천으로서 '환경정의'의 개념 또는 이론을 필요로 한다. 진정한 환경정의론은 한편으로 생태학의 규범적 측면들을 발전시키면서 다른 한편으로 이의 이데올로기의 동원을 막을 수 있는 이론적 및 실천적 토대가 될 것으로 기대된다. 환경정의에 관한 개념적 연구는 주로 사회정의에 관한 철학적 전통, 특히 자유론, 공리주의, 계약론을 포괄하는 자유주의적 정의론, 맑스주의적 정의론 및 포스트모던 정의론 등에서 도출된 주요 개념들을 자연환경에 확대시키고자 한다. 환경정의에 관한 몇몇 학자들, 대표적으로 벤쯔(Wenz), 하비(Harvey), 로와 그리슨 (Low and Gleeson) 등은 다양한 전통을 위에서 제시한 (환경)정의론들을 면밀히 고찰하여, 이들 각각의 한계를 제시하거나 문제점들을 지적하고, 나아가 이들을 종합하고자 했다. 이들의 연구는 환경정의에 관한 다양한 이론들의 특성을 이해하는데 많은 도움을 주지만, 그 자체로 일관성 있는 이론으로 발전하지는 못했다. 이 글에서 제시되는 환경정의론은 인간들 간의 관계, 자연과 인간들 간의 물질적 관계, 그리고 상징적 관계 등에 상응하도록 정의를 3가지 차원, 즉 분배적 정의, 생산적 정의, 승인적 정의로 구분하고자 한다. 이들은 각각 필요의 원칙, 노동의 원칙, 그리고 의사소통의 원칙에 기초하며, 또한 각각 자유주의적, 특히 롤즈의 정의론, 맑스주의 정의론, 그리고 비판이론이나 포스트모던 정의론에서 많은 시사점들을 얻을 수 있다.