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Comparison of Growth and Allometric Change of Stand and Dominant Trees in Pinus koraiensis Plantation over 34 Years

  • Seo, Yeongwan;Lee, Daesung;Chhorn, Vireak;Choi, Jungkee
    • Journal of Forest and Environmental Science
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    • v.34 no.3
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    • pp.235-241
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    • 2018
  • This study was conducted to find out the growth pattern of Pinus koraiensis plantation over 34 years, focusing on DBH, height, basal area and allometric change. Total increment (TI), mean annual increment (MAI) and correlation coefficient were calculated and compared with stand and dominants. Total increment and mean annual increment of both DBH and height of dominants were bigger than those of stand. The difference was apparently shown bigger in DBH than height. Unlike DBH and height the total increment and mean annual increment of basal area per hectare of dominants were distinctively smaller than those of stand. Furthermore MAI of dominant was increasing until age 42, while MAI of stand increased at early ages and then gradually decreased after culmination like MAIs of DBH and height. MAIs of basal area of dead trees at each measurement tended to increase until early age (18 years in this study), while it reached a peak and gradually decrease after that (21 years in this study). Correlation coefficient between DBH and height tended to decrease as both dominant and stand age and the difference between dominant and stand was not clearly shown over the measurement period. Correlation coefficients between DBH and crown width tended to decrease as the trees age and correlation coefficients of dominant were clearly shown smaller than that of stand. Correlation coefficients of height and crown width also was found to be similar to correlation coefficients between DBH and crown. Meanwhile correlation coefficient of height and crown width dropped more radically than coefficient of DBH and crown width as the trees age.

A study of single-phase liquid cooling by multiple nozzle impingement on the smooth and extended surfaces (다중노즐에 의해 분사된 평면 및 확장면의 단상액체냉각에 관한 연구)

  • 소영국;박복춘;백병준
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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    • pp.743-752
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    • 1998
  • Experiments were performed to characterize single-phase heat transfer behavior of submerged liquid jet with multiple nozzle normally impinging on the smooth and extended surfaces. Arrays of 9 and 36 nozzles were used, with diameters of 0.5 to 2.0mm providing nozzle area ratio (AR) from 0.05 to 0.2. The square pin fin arrays were chosen as extended surfaces and the effects of geometrical parameters such as fin height, the ratio of fin width to channel width on heat transfer enhancement were examined. Single nozzle characteristics were also evaluated for comparison. The results clearly showed that heat transfer enhancement could be realized by using multiple nozzles at the constant volume flow rate. The average Nusselt number of multiple nozzle impingement on the smooth surface was correlated by the following equation : Nu/$Pr\frac{1}{3}=0.94 Re^{0.56}N^{-0.12}AR^{0.50}$The average heat transfer coefficients of multiple nozzle impingement on the extended surfaces decreased with increasing fin height and the ratio of fin width to channel width. The effectiveness of ex-tended surfaces ranged from 1.5 to 3.5 depending on the fin height, the ratio of fin width to channel width of pin fin arrays, nozzle number and nozzle area ratio.

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Study on the Morphological Parameters and Evolution of Caragana microphylla Lam. Nebkhas in Inner Mongolia, China

  • Na, Yan;Eerdun, Hasi;Park, Ki-Hyung;Xia, Xian-Dong;Chun, Kun-Woo
    • Journal of Korean Society of Forest Science
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    • v.98 no.2
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    • pp.156-162
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    • 2009
  • Nebkhas are widely distributed in farming-pastoral zones, typical grassland and desert margins. In the southeast of the Inner Mongolia Plateau, it is mainly distributed at the leeward of cultivated land and alluvial fan, severe deterioration rangeland and around residential points. Through the field measurement and statistical analysis of Caragana microphylla Lam. Nebkhas morphological parameters (length, width and height of Nebkhas are included), the results show that there were close correlations between the Nebkhas morphological parameters. The ranges of height and width of Nebkhas changed dramatically and have reached up to 11.44 m and 7.97 m respectively, however, the change range of height was relatively smaller and just 1.09 m. The morphological parameters change of the same type Nebkhas in the same region was large ranging from 0.56 m in height, 3.56 m in width to 6.96 m in length, while the morphological characteristics of the same type Nebkhas in different regions were much similar. A correlation between length and width was significantly positive, but the correlations between height and length, and between height and width were much more complicated. It can be concluded that the Nebkhas in Zhengxiangbai Banner and Taipusi Banner were at the initially growing stage, while the Nebkhas in Huade County belonged to a transitional stage from the growing phase to the stabilizing phase. The changing regularity of distance between Nebkhas in along-wind direction was not consistent.

Characteristics of flow rate according to design parameters of a shroud in outdoor unit (실외기 shroud 설계 인자에 따른 유량 특성)

  • Ryu, Ki-Jung;Kim, Min-Soo;Cha, Woo-Ho;Lee, Kwan-Soo
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.244-249
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    • 2008
  • In this study, the characteristics of flow in outdoor unit were numerically analyzed. Parametric studies were performed to compare the effect of bell mouth height, fan height and fan width concerned with flow rate. The result indicated that the flow rate was dependent on the bell mouth height, while it was negligibly affected by the fan height and fan width. The fan width was found to affect the velocity distribution at heat exchanger face.

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A STUDY ON THE DIMENSIONAL ACCURACY OF MODELS USING 3-DIMENSIONAL COMPUTER TOMOGRAPHY AND 2 RAPID PROTOTYPING METHODS

  • Cho Lee-Ra;Park Chan-Jin;Park In-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.39 no.6
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    • pp.633-640
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    • 2001
  • Statement of problem. Relatively low success rate of root analogue implant system was supposed to be due to the time duration between extraction and implant installation. The use of three-dimensional computer tomography and the reconstruction of objects using rapid prototyping methods would be helpful to shorten this time. Purpose. This aim of this study was to evaluate the application possibility of the 3-dimensional computer tomography and the rapid prototyping to root analogue implants. Material and methods. Ten single rooted teeth were prepared. Width and height of the teeth were measured by the marking points. This was followed by CT scanning, data conversion and rapid prototyping model fabrication. 2 methods were used; fused deposition modelling and stereolithography. Same width and height of this models were measured and compared to the original tooth. Results. Fused deposition modelling showed an enlarged width and reduced height. The stereolithography showed more exact data compared with the fused deposition modelling. Smaller standard deviation were recorded in the stereolithographic method. Overall width error from tooth to rapid prototyping was 7.15% in fused deposition modelling and 0.2% in stereolithography. Overall height showed the tendency of reducing dimensions. Conclusion. From the results of this study, stereolithography seems to be very predictable method of fabricating root analogue implant.

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Development of Allometry and Individual Basal Area Growth Model for Major Species in Korea (우리나라 주요수종의 Allometry와 개체목 흉고단면적 생장모델 개발)

  • Choi, Jung-Kee
    • Journal of Forest and Environmental Science
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    • v.27 no.1
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    • pp.47-54
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    • 2011
  • Allometry and basal area equations were developed with various tree measurement variables for the major species; Quercus variabilis, Quercus mongolica, Pinus koraiensis and Larix leptolepis in Korea. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, and crown width), relative size (relative diameter and relative height) as well as competition measures (competition index, crown class, and live crown ratio).

The Study on Vigor and External Factors of Tree in Damaged Pine Stands by Thecodiplosis japonensis Uchida et Inouye (솔잎혹파리 피해임지내 수목의 외형적 인자와 관련한 수세변동과정 해석)

  • Lee, Chan-Yong;Kim, Joung-Kuk;Chae, Hee-Mun;Lee, Sang-Bae;Won, Dae-Sung
    • Journal of Forest and Environmental Science
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    • v.18 no.1
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    • pp.45-52
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    • 2001
  • This paper investigated external factors (height. crown width. diameter breath height, clear length) of tree and electric resistance ($k{\Omega}$) in damaged forest by Thecodiplosis japonensis Uchida et Inouye. The height. crown width and diameter breath height of tree external factors have high a coefficient of correlation. but clear length has not a coefficient of correlation. In relationship of electric resistance and external factor. big tree that height. crown width. diameter breath height has lower electric resistance value than that of small tree. (low electric resistance value is high tree vigor, high electric resistance value is low tree vigor)) Dead tree have smaller diameter breath height. crown width. higher clear length than survival tree in damaged forest by Thecodiplosis japonensis Uchida et Inouye. To investigation of relationship external factors according to electric resistance value. electric resistance value was divided three class (< $l4k{\Omega}$, possible of survival. $14{\sim}20k{\Omega}$, > $20k{\Omega}$, possible of dead). In lower class(< $l4k{\Omega}$), external factors have bigger which was height. crown width. diameter breath height and lower which was clear length than them of higher class ($14{\sim}20k{\Omega}$, > $20k{\Omega}$). Linear regression solutions of electric resistance and external factors were Y = -0.572 ${\times}$ Height - 1.163 ${\times}$ crown width - 0.242 ${\times}$ diameter breath height + 0.757 ${\times}$ clear length + 25.765. Regression solutions were significant in 5%.

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A Study on Development of an Electromagnetic Inductive Sensor for Automatic Weld Seam Tracking (용접선 자동추적용 전자기유도센서의 개발에 관한 연구)

  • Bae Kang-Yul
    • Journal of Welding and Joining
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    • v.23 no.4
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    • pp.66-72
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    • 2005
  • An electromagnetic inductive sensor consisted of one exciter and three separated (triple) detectors has been developed for both tracking the weld seam of a workpiece and controlling the sensor-to-workpiece distance (height) simultaneously. The left and right detectors are used to track the seam, while the fore and the other two detectors allow the sensor to determine the height and the gap width by being coupled their outputs together. A series of experiments with the proposed sensor located above a mild steel plate containing a weld seam of gap are carried out to examine the feasibility of the sensor. The results revealed that the proposed sensor could fairly well track the desired seam and also well control the height to be constant even when the gap width of the seam varied. The gap width can be also determined during the seam tracking by using the sensor outputs. As a consequence, these can provide the developed sensor with substantial improvement for industrial uses with respect to the previous electromagnetic sensors being used for the weld seam tracking.

Park-Weir Excision for Flaring Alar Correction (넓어진 콧방울의 교정을 위한 Park-Weir 절제술)

  • Han, Sung-Bum;Park, Beyoung-Yun
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.674-678
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    • 2011
  • Purpose: Straight closure line of classic Weir excision leaves visible scars and makes it difficult to precisely approximate resection margins. Hence this study introduces Park-Weir excision that effectively reduces alar width with minimal alar rim scar by 3-dimensional zigzag incision and properly controls the approximation of edges. Methods: From 2008 to 2010, 14 patients underwent Park-Weir excision, crossed wedge excision on alar rim not exceeding 5 mm in width. Each patient was photographed in the same position. Alar width and columellar height against intercanthal distance was compared preoperatively and postoperatively, using image analysis software. Results: Five patients were female and nine were male. Average follow up period was 8 month. Alar width was reduced by 50.50% to 45.96%, original alar width reduced by 8.98% without significant changes in columellar height which was reduced by 0.39%. No visible scar was reported during outpatient follow-up. Conclusion: Park-Weir excision effectively reduces alar width and corrects the flaring of alar without affecting the columellar height. Zigzag incision of Park-Weir excision leaves aesthetically more pleasant scar than straight single incision of classical Weir excision.

The Effect of Height Increase Elevator Shoes Insole on Gait and Foot Pressure (키높이 깔창이 성인남성의 보행 및 발의 압력분포에 미치는 영향)

  • Goo, Bong-Oh
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.2
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    • pp.199-205
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    • 2011
  • Purpose: The purpose of this study was to investigate the effect of 0cm, 2.5cm, 5cm height increase elevator shoes insole on gait and foot pressure Methods: Fifteen young adult were recruited this study. Gait and foot was measured by Gait AnalyzerTM(Tech Storm Inc. korea). Statistical analysis was used one-way ANOVA to know difference between 0cm, 2.5cm insole and 5cm insole Results: There was no significantly difference on foot length, foot width, foot angle, step time during gait. But step length and step width was significantly difference during gait. There was no significantly difference on gait ratio during stance phase. There was significantly difference on forefoot pressure and rearfoot pressure ratio. Conclusion: These results indicate that height increase elevator shoes insole may be caused step length, step width decreaseed during gait. It caused forefoot pressure increased and rearfoot pressure decreased on foot.