• Tunnel and Underground Space
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• v.9 no.1
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• pp.27-35
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• 1999

The characteristics of heat conduction for the heat source boundary like an arch shape cavern are different from those for the semi-infinite or circular boundary which can be driven theoretically. A new form of transient heat conduction equation in rock mass around the arch shape cavern is evaluated with analyzing the pattern of the rock temperature distribution measured at the cold storage pilot plant. The new equation, which is driven by adopting a shape function, $SF=\sqrt{logx_0/log(x_0+x)}$ to the solution for a semi-infinite boundary, has the semi-radial form of temperature variation with distance. And, thermal properties of rock mass are estimated by comparing the rock temperature distributions by this equation with those by measurement. Thermal conductivity and specific heat of rock mass are estimated as giving the difference of 20~25% compared to those of laboratory scale. This difference seems to be caused by discontinuity like joint and water content in rock mass.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.6
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• pp.668-673
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• 2014

Cold and Heat pattern identification(CHPI) in traditional East Asian medicine(TEAM) is one of the major indicator to distinguish characteristics of disease and to determine treatment method. Basic parameters to determine CHPI include the pulse rate, respiration rate, and pulse power. Studies to associate physiological responses of human body by cold stress(CS) with CHPI in TEAM were rarely done so far. This study aims to explore the effects of cold stress on pulse signal via a feasibility study for three subjects and investigate some indices which can reflect autonomic nerve reaction(ANR). We measured radial pulse signals and respiration signal of the investigated subjects before the CS, during the CS which continues for 5 minutes, and immediately after the CS, respectively. Finally, we analyzed the pulse rate (P), respiration rate (R), pulse power, pulse depth, and pulse rate per respiration (P/R ratio). As a result, the P/R ratio showed a consistently decreasing tendency through the CS stimulation process, while other parameters behaved more complex and in subject-specific ways. It implies that, among candidate parameters, the P/R ratio is a simple but the most probable parameter that can be used as the ANR indicator. This result is also consistent with the theory in TEAM scripts, in which the P/R ratio is predicted to be a direct indicator for the CHPI. This pilot study shows that P/R ratio can be more appropriately associated with the ANR than heart rate or respiration rate alone. Extensive studies will be necessary to verify or confirm the P/R ratio as an appropriate and well defined parameter for ANR.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.379-385
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• 1991

Morphological changes of starch granules from 12 different varieties of rice were examined by scanning electron microscopy during heating at 2.5% (w/v) concentration. Rice starch granules proceeded through a similar pattern of progressive morphological changes daring heating, regardless of variety. Rice starch granules began to swell radially in the initial stage of gelatinization and then undergo radial contraction and random tangential expansion to form complex structures in the latter stage of gelatinization temperature range. At higher temperatures, starch granules softened and melted into thin flat discs, and then stretched into thin filaments to form three-dimensional networks. These progressive morphological changes were reflected in the changes of swelling power, solubility and amylograph viscosity of starch. During the transition of melting or softening, swelling power, solubility and amylograph viscosity increased rapidly. The time of loss of granular structure of starch depended on gelatinization temperature range. The ratio of amylose to amylopectin was largely responsible fur the rate of melting or softening and the fineness of a three-dimensional filamentous network above the gelatinization temperature range. Therefore, both the gelatinization temperature range and amylose content of starch affect the rate of cooking, and amylose content of starch affects the final texture of cooked starch paste.

• The Journal of Korean Medicine
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• v.31 no.2
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• pp.114-123
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• 2010

Objectives: This study was performed to investigate the effect of cold stress on heart rate variability and peripheral blood flow by Doppler ultrasound in healthy subjects. Methods: We classified the subjects by their Yin or Yang tendency using a Yin-Yang questionnaire. Cold stress was taken on the left hand of subjects for 10 seconds. Heart rate variability and peripheral blood flow were measured on the right radial artery before and after cold stress. Results: The Yang tendency group showed a significant decrease of heart rate after cold stress which was not seen in the Yin tendency group. The Yang tendency group showed a decrease of LF, total power, and increase of HF after cold stress, while the Yin tendency group showed the opposite. However, there were no statistically significant differences of heart rate variability analysis between the results of the two groups before and after cold stress. Recovery time of blood flow velocity by ultrasound Doppler was significantly different between the Yin and Yang tendency groups after cold stress. Conclusion: These results suggest that people with Yin or Yang tendency may show different responses in the autonomic nervous system. Further modified studies may include the responses to various manipulation techniques in acupuncture treatment and the individual responses according to pattern identification in traditional Korean medicine.

• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.869-877
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• 2020

A 24-month Advanced Power Reactor 1400 (APR1400) core with a very-low-boron (VLB) concentration has been investigated for an inherently safe and high-performance PWR in this work. To develop a high-performance APR1400 which is able to do the passive frequency control operation, VLB feature is essential. In this paper, the centrally-shielded burnable absorber (CSBA) is utilized for an efficient VLB operation in the 24-month cycle APR1400 core. This innovative design of the VLB APR1400 core includes the optimization of burnable absorber and loading pattern as well as axial cutback for a 24-month cycle operation. In addition to CSBA, an Er-doped guide thimble is also introduced for partial management of the excess reactivity and local peaking factor. To improve the neutron economy of the core, two alternative radial reflectors are adopted in this study, which are SS-304 and ZrO₂. The core reactivity and power distributions for a 2-batch equilibrium cycle are analyzed and compared for each reflector design. Numerical results show that a VLB core can be successfully designed with 24-month cycle and the cycle length is improved significantly with the alternative reflectors. The neutronic analyses are performed using the Monte Carlo Serpent code and 3-D diffusion code COREDAX-2 with the ENDF/B-VII.1.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.2
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• pp.188-193
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• 2021

On March 13, 2018 two postflexion larval specimens (18.28 mm and 16.80 mm in standard length) belonging to the family Cryptacanthodidae, suborder Zoarcoidei were collected from Sokcho and Gangneung in Gangwon Province. The family Cryptacanthodidae comprises 4 species worldwide: 3 in the North Pacific Ocean and 1 in the western North Atlantic Ocean. As a result of analyzing 620 bp of the mtDNA COI region, the two postflexion larvae collected in this study were identified as Cryptacanthodes bergi by 99.5% agreement with C. bergi adult registered in NCBI. Postflexion larvae of C. bergi are compressed with large eyes and radial pectoral fins and the anus located in front of the center of the body. Melanophores were intensively distributed along the dorsal midline, except for caudal peduncle, and sporadically distributed on the back of the anus. In addition, there were limited star-like melanophores on the back of the gut. This species showed 0.058 genetic distance when compared mtDNA COI region of C. aleutensis, and it was well distinguished in the distribution pattern of black vesicles of the head, count and measurement traits. Considering the morphological and ecological characteristics of this species, we suggest a new Korean name, " Gwisin-jang-gaeng-i ".

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.13-30
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• 2024

Swietenia mahagoni is one of the commercial timbers in Indonesia. Mahogany heartwood is an important characteristic as it relates to the natural durability and aesthetics of the wood. Lipophilic extractives are known to be involved in the heartwood formation process. Therefore, this study aims to determine the lipophilic compounds associated with heartwood formation. The n-hexane extract from sapwood and heartwood samples (1 to 5 years) was analyzed by gas chromatography-mass spectrometry. The results showed that the content of n-hexane extract ranged from 0.76% to 2.45% based on dry wood. The main group of compounds identified in the lipophilic fraction consisted of sterols (β-sitosterol, stigmasterol, campasterol, and cyclolaudenol), fatty acids (palmitic, oleic, linoleic, and stearic acid), and hydrocarbons (pentadecane, 1-octadecane, hexadecane, cyclotetracosane, cycloeicosane, and cyclooctacosane) after heartwood formation. In addition, the hydrocarbon fraction was the largest, followed by sterols, fatty acids, and 1-heneicosanol. In the radial variation, the distribution of fatty acids was greater in the sapwood than in the heartwood (4-year-old). However, the reverse pattern was found at the age of 5 years. The lipophilic fraction was generally more abundant in the heartwood compared to the sapwood, especially at 5 years of age, with much higher levels than when the heartwood was forming (4 years). These findings show that when the heartwood formation begins, the lipid composition was not fully metabolized at the beginning of heartwood formation compared to 5-year-old trees.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.77-84
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• 2000

In order to understand the chemical binding forms of Cd in terms of its binding strength in wood, the radial distribution of it through dendroanalysis and its different chemical fractions in trunk wood of mature red pine(Pinus densiflora L.) trees grown in a relatively unpolluted area, in Kangwon-Province, were examined. Total Cd concentration in stem wood was determined by dry digestion and $H_2O$ and 0.01 M solutions of citric acid, malic acid, $CaCl_2$, $MgCl_2$, $Na_2EDTA$ were used as extracting solutions for Cd. Extracting efficiencies of applied solutions were expressed as % of Cd concentration extracted by $Na_2EDTA$ which extracted all Cd instead of Cd total concentration. Total concentration of Cd decreased from the innermost rings near pith towards the the outermost rings near cambium. Especially through the transition zone this tendency was observed clearly. $H_2O$ was the least effective extractant of Cd, then extracting efficiency increased in the order $MgCl_2$ < $CaCl_2$ $Na_2EDTA$ (extracted all Cd). According to the radial position, extracting efficiency of Cd was ranging from 7 to 30% by $H_2O$ and even from 60 to 95% by citric acid. The Cd extracting efficiencies of $H_2O$ and organic acids increased continuously from the stem center to outermost annual rings, whereas salts showed somewhat different tendency, suddenly decreasing near the outermost ring. The results are discussed with regard to the different chemical binding forms of Cd and the mobility of Cd in wood and comparable with ones in previous studies on Pinus sylvestris and Quercus patraea. According to the results, usefulness of radial distribution pattern of Cd in pine tree trunks for retrosective biomonitoring is questioned.

• The Journal of Korean Medicine
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• v.32 no.5
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• pp.50-65
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• 2011

Objectives: Moxibustion has been used for various post-stroke symptoms and has also been known to have effect on peripheral blood flow. This study investigated the effect of moxibustion on radial artery blood flow by Doppler ultrasound and on heart rate variability in post-stroke hemiplegia patients. Methods: Moxibustion was applied on the points of LI4, TE3, TE5 and LI11 on the affected side, and blood flow of the radial artery was measured using the Minimax-Doppler-K device. Blood flow velocity and pulsation index were analyzed before, during, and after moxibustion. Simultaneously LF, HF, and LF/HF as variables for HRV were measured by FM-150. Results: The mean value of blood flow velocity in all patients (n=23) showed significant increase between before and after moxibustion, but there was no significant difference in pulsation index and LF, HF, LF/HF ratio between before and after moxibustion. In Yin (n=9) and Yang (n=14) groups, both showed significant increase of blood flow velocity between before and after moxibustion, but there was no significant difference in pulsation index and LF, HF, LF/HF ratio between before and after moxibustion. In Deficiency (n=14) and Fullness (n=9) groups, only the Deficiency group showed significant increase of blood flow velocity between before and after moxibustion, while the Fullness group showed no significant difference in blood flow velocity between before and after moxibustion, and also there was no significant difference in pulsation index and LF, HF, LF/HF ratio between before and after moxibustion. Conclusions: This study suggests that moxibustion on LI4, TE3, TE5 and LI11 on the affected side of stroke patients increase the peripheral blood flow in the affected arm, which was most remarkable in those with Yin and Deficiency pattern.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.1 s.24
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• pp.21-28
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• 2003

This study was aimed at suggest a proper planning method to select a optimal forest road network in mountains forest using GIS(Geographic Information System). To examine the field applicability, the method was applied to the National Forest at Mt. Kumsan in Namhae-gun, Gyungsangnam-do. The main results from altogether six alternative road route plans were derived from these criteria obtained the alternative route plan No.2 has two layout criteria, longitudinal gradient and earth work volume, and it showed similar pattern of existing forest road network which was designed mainly ground slope and longitudinal gradient. The alternative route plan No.6 has four criteria, longitudinal gradient, earth work volume, investment effect and landscape impact. It was different for the lowest forest road density among the alternatives and the pattern of the forest road layout was radial form, which was also quite different to other alternatives. For optimal forest road network planning, GIS provide the efficient and resonable solutions for decision making to provide the support for evaluation about various alternative road networks. If detailed inventory and relevant data are provided and also clear and objective indicators for evaluations are set up, it could be applied to preliminary analysis and detail planning stage to prevent undesirable effect such the land slide and soil erosion due to inadequate planning for forest road network.