• Title/Summary/Keyword: Damage threshold

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Thermal Distribution in Living Tissue during Warm Needling Therapy (온침 시술 시 생체 조직 내 열분포 분석에 관한 연구)

  • Kim, Jongyeon;Lee, Jong-Soo
    • Journal of Korean Medicine Rehabilitation
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    • v.24 no.3
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    • pp.111-119
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    • 2014
  • Objectives This study aims to analyze a thermal distribution in biological living tissue during warm needling therapy by using a finite element method. The analysis provides an understanding of warm needling's efficacy and safety. Methods A model which consisted of four-layered tissue and stainless steel needle was adopted to analyze the thermal distribution in living tissue with a bioheat transfer analysis. The governing equation for the analysis was a Pennes' bioheat equation. A heat source characteristic of warm needling therapy was obtained by previous experimental measurements. The first analysis of the time-dependent temperature distribution was conducted through points on a boundary between the needle and the tissue. The second analysis was conducted to visualize the horizontal temperature distribution. Results When heat source's peak temperatures was above $500^{\circ}C$ and temperature rising rates were relatively slow, the peak temperature at skin surface exceeded a threshold of pain and tissue damage ($45^{\circ}C$), whereas when the peak temperature was around $400^{\circ}C$, the peak temperature at the skin surface was within a safe limit. In addition, the conduction of combustion energy from the moxa was limited to the skin layer around the needle. Conclusions The results suggest that the skin layer around the needle can be heated effectively by warm needling therapy, but it appears to have little effect at the deeper tissue. These findings enhance our understanding of the efficacy and the safety of the warm needling therapy.

Optimum Stand Density Control Considering Stability in Larix kaempferi Forests (임분 안정성을 고려한 일본잎갈나무 임분밀도 관리의 적정 수준)

  • Park, Joon Hyung;Chung, Sang Hoon;Kim, Sun Hee;Lee, Sang Tae
    • Journal of Korean Society of Forest Science
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    • v.109 no.2
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    • pp.202-210
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    • 2020
  • This study investigated the optimal levels of stand density control considering the stability of Larix kaempferi stands. A stand density management diagram was developed from 259 sample plots. Based on these data, we determined an optimal level of the stand density control by identifying the relationship between the relative yield index (Ry) and height-to-diameter ratio. The estimated r-square (R2) of the stand density management diagram is 0.600. The analysis of the relationship between Ry and the slender tree incidence showed that when the stand density exceeded a certain threshold and the ratio of slender trees rapidly increased. The critical value of Ry was 0.63. The results of this study are expected to contribute to the establishment of stand management strategies that can reduce damage from natural causes, such as wind and snow, and to develop stand practice systems for the improved productivity of commercial forests.

Prediction of Dormancy Release and Bud Burst in Korean Grapevine Cultivars Using Daily Temperature Data (기온자료에 근거한 주요 포도품종의 휴면해제 및 발아시기 추정)

  • Kwon Eun-Young;Song Gi-Cheol;Yun Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.3
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    • pp.185-191
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    • 2005
  • An accurate prediction of dormancy release and bud burst in temperate zone fruit trees is indispensable for farmers to plan heating time under partially controlled environments as well as to reduce the risk of frost damage in open fields. A thermal time-based two-step phenological model that originated in Italy was applied to two important grapevine cultivars in Korea for predicting bud-burst dates. The model consists of two sequential periods: a rest period described by chilling requirement and a forcing period described by heating requirement. It requires daily maximum and minimum temperature as an input and calculates daily chill units (chill days in negative sign) until a pre-determined chilling requirement for rest release is met. After the projected rest release date, it adds daily heat units (anti-chill days in positive sign) to the chilling requirement. The date when the sum reaches zero isregarded as the bud-burst in the model. Controlled environment experiments using field sampled twigs of 'Campbell Early' and 'Kyoho' cultivars were carried out in the vineyard at the National Horticultural Research Institute (NHRI) in Suwon during 2004-2005 to derive the model parameters: threshold temperature for chilling and chilling requirement for breaking dormancy. The model adjusted with the selected parameters was applied to the 1994-2004 daily temperature data obtained from the automated weather station in the NHRI vineyard to estimate bud burst dates of two cultivars and the results were compared with the observed data. The model showed a consistently good performance in predicting the bud burst of 'Campbell Early' and 'Kyoho' cultivars with 2.6 and 2.5 days of root mean squared error, respectively.

Effect of UV Radiation on Early Growth of Korean Rice Cultivars(Oryza sativa L.)

  • Choi, Kwan-Sam;In, Jun-Gyo;Kang, Si-Yong;Bae, Chang-Hyu;Lee, Hyo-Yeon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.3
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    • pp.296-301
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    • 1999
  • The concerns on the crop damage by ultraviolet (UV) radiations is increasing owing to the decrease of their absorbing stratospheric ozone in the tropospheric. Cultivar differences on early growth of UV radiation among five Korean rice cultivars, four japonica types and one Tongil type (indica-japonica cross hybrid), were studied. Pot-seeded rice plants were grown under four different radiation conditions, i.e., visible radiation only, visible radiation with supplemented with high or low dose of UV-B (280~320 nm in wavelength) and UV-C (less than 280 nm in wavelength). The inhibitory degree on plant height, shoot and root weight and length of leaf blade and leaf sheath were determined at 40 days after seeding. UV-C showed the most severe inhibitory effect on the degree of biomass gain and leaf growth in most cultivars examined, followed by high UV-B and low UV-B. Among the cultivars used, the Kuemobyeo was the most sensitive cultivar and had not repair or showed resistance ability to continued irradiation of UV radiation. However, Janganbyeo and Jaekeon showed different responses that the elongation of leaf blades was promoted on 2nd and 3rd leaves and inhibited on 4th and 5th leaves but this inhibitory degree was reduced on 6 th and 7th leaves. Such tendency on leaf growth means that both cultivars had low sensitivity and most resistant ability to continued irradiation of UV radiation. While Tongil showed different response to enhanced UV radiation, ie., low UV-B promoted leaf growth but the inhibitory was severely increased by continued irradiation of high UV-B and UV-C, which means that Tongil had high threshold of UV radiation for response as an inhibitory light of plant growth. The results of this study indicate that the differences on sensitivity or resistant to the effects of UV radiation were existed among Korean rice cultivars.

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Individual Pig Detection Using Kinect Depth Information and Convolutional Neural Network (키넥트 깊이 정보와 컨볼루션 신경망을 이용한 개별 돼지의 탐지)

  • Lee, Junhee;Lee, Jonguk;Park, Daihee;Chung, Yongwha
    • The Journal of the Korea Contents Association
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    • v.18 no.2
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    • pp.1-10
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    • 2018
  • Aggression among pigs adversely affects economic returns and animal welfare in intensive pigsties. Recently, some studies have applied information technology to a livestock management system to minimize the damage resulting from such anomalies. Nonetheless, detecting each pig in a crowed pigsty is still challenging problem. In this paper, we propose a new Kinect camera and deep learning-based monitoring system for the detection of the individual pigs. The proposed system is characterized as follows. 1) The background subtraction method and depth-threshold are used to detect only standing-pigs in the Kinect-depth image. 2) The standing-pigs are detected by using YOLO (You Only Look Once) which is the fastest and most accurate model in deep learning algorithms. Our experimental results show that this method is effective for detecting individual pigs in real time in terms of both cost-effectiveness (using a low-cost Kinect depth sensor) and accuracy (average 99.40% detection accuracies).

Study on the Characteristics of Surface Ozone Distributions and the Ozone Critical Levels to Vegetation in the South Korea (남한 지역의 지면 오존 농도 특성과 식생에 대한 임계값 적용 연구)

  • Koo, Hae-Jung;Park, Soon-Ung
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.3
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    • pp.310-320
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    • 2008
  • Concentration of tropospheric ozone ($O_3$) was investigated for the South Korea. And then the critical ozone levels, expressed as AOT40 (Accumulated exposure over a threshold of 40 ppb) to vegetation have been used in this region within the UNECE (United Nations Economic Commission for Europe) Convention on Long-Range Trans-boundary Air Pollution (CLRTAP). Hourly ozone concentration data from 1996 to 2001 at 26 air monitoring stations was used to estimate the exceedance of the critical levels. It was calculated for daylight hours for each station, and mapped using surface interpolation over the South Korea. The critical levels of ozone have shown the highly exceeded value in the Gyeonggi region, southern coastal region and central inland of the South Korea. It was some different from the typical ozone distribution which represented highly in the western inland and coastal regions. The area exceeding the critical level for crops was founded to be more than 40% of the whole South Korean territory. While that for trees was to be about 17% of the South Korea. The critical ozone critical level was based upon data from experiments on specific species, and thus may not be fully representative for all types of vegetation. Nevertheless, the critical level and its exceedance of the ozone concentration would be one of the useful tools for international agreements on abatement strategies to prevent ecosystem damage.

Construction and Operation Characteristics of the Automated Lightning Warning System Based on Detections of Cloud-to-Ground Discharge and Atmospheric Electric Field (낙뢰와 대기전계의 탐지를 기반으로 하는 자동낙뢰경보시스템의 구성과 운용특성)

  • Shim, Hae-Sup;Lee, Bok-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.11
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    • pp.82-88
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    • 2013
  • It is important to give lightning warning prior to a cloud-to-ground (CG) discharge within an Area of Concern (AOC) because most of lightning damage and victim are usually occurred by the first lightning in the AOC. The aim of this study is to find the optimal operation conditions of the automated lightning warning systems in order to make the best use of the available data. In this paper, the test-operated results of the automated lightning alert and risk management system (ALARM) based on detections of CG discharge and eletrostatic field and optimized at probability of lightning have been described. It was possible to obtain the following warning performance parameters: probability of detection (POD), false alarm ratio (FAR), probability of lightning (POL) and failure-to-warn rate (FTW). The data obtained from trial operation for 5months were not sufficient but the first analysis of domestic lightning warning was carried out. We have observed that the evaluated statistical results through trial operation depend on the various factors such as analysis methods and criteria, topographical conditions, etc. Also we suggest some methods for improvement of POL and POD including the finding of the optimal electric field threshold level to be used, based on the high values of FAR and FTW found in this work.

Etching of the PDP barrier rib material using laser beam (레이저빔에 의한 PDP 격벽 재료의 식각)

  • Ahn, Min-Young;Lee, Kyoung-Cheol;Lee, Hong-Kyu;Lee, Sang-Don;Lee, Cheon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.6
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    • pp.526-532
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    • 2000
  • The paste on the glass or fabrication of the PDP(Plasma Display Panel) barrier rib was selectively etched using focused A $r_{+}$ laser(λ=514 nm) and Nd:YAG(λ=532, 266 nm) laser irradiation. The depth of the etched grooves increase with increasing a laser fluence and decreasing a laser beam scan speed. Using second harmonic of Nd:YAG laser(532 nm) the etching threshold laser fluence was 6.5 mJ/c $m^2$ for the sample of PDP barrier rib. The thickness of 180 ${\mu}{\textrm}{m}$ of the sample on the glass was clearly removed without any damage on the glass substrate by fluence of 19.5J/c $m^2$beam scan speed of 20${\mu}{\textrm}{m}$ /s. In order to increase the etch rate of the barrier rib material barrier rib samples heated by a resistive heater during laser irradiation. The heated sample has many defects and becomes to be fragile. This imperfection of the structure compared to the sample without heat treatment allows the effective etching by the focused laser beam. The etch rates were 65${\mu}{\textrm}{m}$/s and 270 ${\mu}{\textrm}{m}$/s at room temperature and 20$0^{\circ}C$, respectively.y.

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Crystal growth and optical properties of Zn and Yb co-doped $LiNbO_3$ rod-shape single crystal by micro-pulling down method (Micro-pulling down법으로 성장시킨 Zn와 Yb를 첨가한 $LiNbO_3$ 단결정의 광학적 특성)

  • Her, J.Y.;Lee, H.J.;Yoon, D.H.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.1
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    • pp.11-14
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    • 2009
  • Yb and Zn co-doped $LiNbO_3$ single crystal rods which had a diameter of 2 mm and a length of $15{\sim}25 mm$ were grown by micro-pulling down (${\mu}-PD$) method. The single crystals were successfully grown and had a uniform diameter and a smooth surface without crack. We realized of $LiNbO_3$ single crystals were hexagonal structure to compare with peaks of $LiNbO_3$ powder by Raman spectra. The threshold level of Zn concentration which is effective for optical damage were observed as about 1 mol% with IR transmission spectra.

Effect of Density of Helicotylenchus dihystera on Growth of Solanum lycopersicum (나선선충 접종 밀도가 토마토 생육에 미치는 영향)

  • Kim, Donggeun;Ryu, Younghyun;Lee, Younsu;Choi, Insoo;Hu, Changsuk
    • Research in Plant Disease
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    • v.20 no.2
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    • pp.107-111
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    • 2014
  • A greenhouse experiment was conducted to examine the effect of initial population density (Pi) of Helicotylenchus dihystera on six commercial tomato cultivars. Two-week-old tomato seedlings of six commercial cultivars were transplanted in d-10-cm clay pot and was inoculated with to give 0, 0.02, 0.2, and 2 nematodes/g soil. Plants were grown in a greenhouse for 60 days. Root and plant weights were unaffected but plant height declined only at inoculum level of 2 nematodes/g soil. At the highest initial population density (2 nematodes/g soil), plant height of tomato cv. Poseidon was reduced by 24%. Tomato cv. Hoyong produced the most nematodes with 7.0 nematodes/g soil and the least was tomato cv. Miniheuksu with 2.2 nematodes/g soil.