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Design Improvement of Mechanical Transmission for Tracked Small Agricultural Transporters through Gear Strength Analysis

  • Kim, Hong-Gon;Jo, Yeon-Ju;Kim, Chul-Soo;Han, Yong-Ho;Kim, Dae-Cheol
    • Journal of Biosystems Engineering
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    • v.41 no.1
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    • pp.1-11
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    • 2016
  • Purpose: The gear strength of a new mechanical transmission designed to increase the loading weight of small 4.8 kW tracked agricultural transporters was analyzed. Design improvements to increase the gear strength and reduce the gear weight were proposed after examining the parameters. Methods: Sixteen operators from three regions were surveyed to obtain the usage profile of small 4.8 kW transporters. Gear strength was evaluated by calculating contact stress and tooth root stress using commercial software following ISO 6336. Results: From the strength calculation for each gear pair, contact stress smaller than tooth root stresses were produced in all gear pairs. The safety factors in most cases exceeded 1.0, except in the case of gear pair II in group II. The design life of the transporter using gear pair II in group II was 42% under harsh conditions-thus, this design life needs improvement. A robust design was proposed by examining the relevant parameters (face width and profile shift coefficient) to increase the design life of the transporter. In addition, a lightweight design for gear pair I in group II that was considered overdesigned was proposed by examining the face width to reduce the weight of the drive gear by 42% and that of the driven gear by 30%. Conclusions: The Safety factor for the design life was examined through a gear strength analysis. After examining the relevant parameters, conditions for strength improvement were proposed to increase design life or adjust overdesigned gear. However, load conditions differ depending on the working conditions or user's preferences; therefore, it is necessary to conduct further studies in various regions.

Plant Regeneration and Transformation of Kentucky Bluegrass(Poa pratensis L.) via the Plant Tissue Culture (조직배양을 이용한 Kentucky bluegrass(Poa pratensis L.)의 식물체 재분화 및 형질전화 조건의 검토)

  • Miki Kusano;Koichi Tohyama;Bae, Chang-Hyu;Riu, Key-Zyung;Lee, Hyo-Yeon
    • Journal of Plant Biotechnology
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    • v.30 no.2
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    • pp.115-121
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    • 2003
  • In this study, plant regeneration and Agrobacterium tumefaciens-mediated transformation Kentucky bluegrass(Poa pratensis L.) were evaluated. Three different types of calli were produced depending on the combinations of growth regulators. They were non-friable brown or gray-colored callus (type I), compact, friable and yellow or white-colored callus (typeII), and soft, watery translucent callus with differentiated structure (typeIII). The highest regenerable organogenic callus (typeII) was obtained on the medium containing 1mg/L, 2,4-D and 0.1mg/L BA. Additionally, the production of typeII calli increased significantly when AgNO$_3$ was added to the callus induction and growth medium. The highest frequency of multiple shout formation from typeII callus was obtained on MS medium containing 1mg/L BA and 1mg/L Thidiazuron(TDZ). The organogenic calli(typeII) were inoculated with Agrobacterium tumefaciens strain EHA101 harboring the binary vector pIG121Hm with $\beta$-glucuronidase gene, and various factors were found to influence the transfer-DNA delivery efficiency. The highest transient GUS activity was observed on typeIIcallus. In the present work, we reported the first transient GUS activity of Kentucky bluegrass mediated by Agrobacterium tumefaciens. Our system may contribute to genetic improvement for breed-recalcirtrant grass species, Kentucky bluegrass.

Magnetic resonance imagining findings of the white matter abnormalities in the brain of very-low-birth-weight infants (극소 저체중 출생아에서 뇌백질 병변의 MRI 소견)

  • Choi, Jae Hyuk;Chang, Young Pyo
    • Clinical and Experimental Pediatrics
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    • v.52 no.10
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    • pp.1127-1135
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    • 2009
  • Purpose : To observe the abnormal white matter findings on the magnetic resonance imaging (MRI) scans of very-low- birth-weight (VLBW) infant brains at term-equivalent age and to determine the clinical risk factors for the development of periventricular leukomalacia (PVL). Methods : In all, MRI was performed in 98 VLBW infants and the white matter abnormalities were observed. Clinical risk factors for cystic and noncystic PVL were determined. Results : MRI scans of 74 infants (75.5%) showed diffuse excessive high signal intensity (DEHSI) in the periventricular white matter, 17 (17.3%) lateral ventricle dilation, 5 (5.1%) and 11 (11.2%) focal punctate lesions and cystic changes in the periventricular white matter, respectively, 9 (9.1%), germinal layer hemorrhage (GLH) or subependymal cysts 3 (3.1%) intraventricular hemorrhage (>grade 2) 2 (2.0%) posthemorrhagic hydrocephalus and 2 (2.0%) periventricular hemorrhagic infarct. Gestational age (GA), 1-minute Apgar score, Clinical Risk Index for Babies-II (CRIB-II) score, and inotrope use, and GA, CRIB-II score, postnatal steroid administration, inotrope use, and abnormal white blood cell (WBC) count at admission were related to cystic PVL and noncystic PVL development, respectively (P<0.05). However, in logistic regression analysis, CRIB-II (odds ratio, 1.63, 295% confidence interval, 1.15-2.30 P=0.006) for cystic PVL, and GA (odds ratio 0.90, 95% confidence interval, 0.82-0.99 P=0.036) for noncystic PVL were only significant independently. Conclusion : White matter abnormalities could be observed on MRI scans of the VLBW infant brains at term-equivalent age, and CRIB-II and GA were only independently significant for cystic and noncystic PVL development, respectively.

Supraventricular Arrhythmias in the Surgical Intensive Care Unit (외과계 중환자실에서 발생한 상심실성 부정맥)

  • Yang, Song-Soo;Hong, Suk-Kyung
    • Journal of Trauma and Injury
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    • v.21 no.2
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    • pp.85-90
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    • 2008
  • Purpose: Supraventricular arrhythmia is a well-known complication of cardiothoracic surgery, and is common in patients wirth underlying cardiovascular disease. Also, it's treatment and prognosis are well known. However the incidence, the contributing factors, and the prognosis for supraventricular arrhythmias in noncardiothoracic surgical patients are less well known. This study was undertaken to investigate the incidence, the clinical presentation, the prognosis, and the factors comtributing to the prognosis for supraventricular arrhythmia in the surgical intensive care unit. Methods: We performed a retrospective study of 34 patients with newly developed or aggravated supraventricular arrhythmias in the surgical intensive care unit between March 2004 and February 2005. The incidence, the risk factors, and the prognosis of supraventricular arrhythmias were analyzed. Results: During a 12month period, the incidence of supraventricular arrhythmia was 1.79% (34/1896). Most patients had pre-existing cardiovascular disease and sepsis. The mortality rate was 29.4%, and the most common cause of death was multiple organ failure due to septic shock. The mean value of the APACHE II score was 20.9, and the surgical intensive care unit and the hospital lengths of stay were 9.9 days and 25.8 days, respectively. The APACHE II score measured when the arrhythmia developed was a significant factor in predicting mortality, Conclusion: Supraventricular arrhythmias result in increased mortality and increased length of stay in both the surgical intensive care unit and the hospital. The arrhythmia itself did not cause death, but a high APACHE II score incicated a poor prognosis. This may reflect the severity of the illness rather than an independent contributor to mortality.

A Study on Store Image Preferences which is Followed by Clothing Buying Motives (II) - As Object of Ewha Womans Student - (의복 구매동기에 따른 점포이미지 선호도에 관한 연구(II) - 이대생을 중심으로 -)

  • Lim, Sook Ja;Lee, Joo Eun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.1
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    • pp.3-10
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    • 1993
  • This study intends to provide a beneficial foundation which can aid our understanding of how a clothing consumer group can be classified according to the clothing buying motives, and what differences are there about the importances store image attribute among them and how consumer's preferences to the store image are shown differently among them and ultimately, some concrete data which can be useful in establishing efficient store image strategies for clothing stores. 484 subjects were gathered through convenience sampling method and, for data analysis, cronbach' ${\alpha}$, frequency, percentage, mean, ${\chi}^2$-text, t-test, ANOVA, Duncan Multiple Range Test, Factor Analysis, Cluster Analysis were conducted. the results are as follows; 1. three kind of factors in the clothing buying motives were determined for analysis of consumers group and by which it was revealed as to be significant for us to classify them three subdivisions; those of fashion pursuit group, self display group, financial utilitarian group. 2. Importance on store image attribute was revealed that Ewha students regarded quality, price, more important factors than others. 3. Store image preferences show significantly when concerned with quality, price, fashion, impression and age of store personnel, convenience for exchanging and returning goods, credit, delivery and repair, mailing of catalogue and discount coupon, bightness of store among consumer groups.

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Study of Disclusion Time during Mandibular Eccentric Movement in Myofascial Pain Syndrome Patients by T-Scan II, Computerized Occlusal Analysis System (컴퓨터 교학분석기인 T-Scan II를 이용한 측방운동시 구치부 이개시간에 관한 연구)

  • Shin, Jun-Han;Kwon, Jeong-Seung;Kim, Seong-Taek;Park, Hyung-Uk;Choi, Jong-Hoon
    • Journal of Oral Medicine and Pain
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    • v.36 no.3
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    • pp.187-197
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    • 2011
  • Temporomandibular disorders(TMD) is a collective term which is embracing a number of clinical problems that involve the masticatory musculature, the TMJ and associated structures, or both. Myofascial pain, which is a kind of masticatory muscle disorder of TMD, is the sensory, motor, and autonomic symptoms caused by myofascial trigger points. There has been some controversies regarding etiologies of TMD and MFP. Especially the issue of occlusal conditions has been a critical issue for long time. Despite much efforts, the results of studies regarding occlusal conditions were contradictory. These controversies might be mostly due to various factors resulting from the complex nature of TMD, however, inaccurate and inappropriate study design, selection criteria, methodologies also play significant roles. Recently, a computerized occlusal analysis system, T-Scan II which made it possible to reveal quantifiable time data and relative force data for analyzing occlusion, was introduced. Some authorities suggested that the concept of disclusion time and prolonged disclusion time of posterior tooth and MFP are related using T-Scan II. But the previous studies which used T-SCAN II are not reliable for they did not provide accurate diagnostic criteria of MFP. Morever they did not compare with controls, and had many other problems. The purpose of this study was to evaluate the relationship between MFP and prolonged disclusion time of posterior tooth, which is one of the occlusal factors of TMD, by selecting 30 subjects as the study group through strict criteria and comparing them with 38 controls using T-SCAN II, computerized occlusal analysis system. The results, statistically analyzed, are summarized as follows: 1. Cronbach ${\alpha}$ coefficient of repeated measurements of disclusion time was 0.92. 2. There were no statistically significant differences at repeated measured disclusion time of both side between control and study group. 3. There was no statistically significant diffefence in the disclusion time between right and left side. From the results above, we can suggest that there was no relationship between MFP and disclusion time, so irreversible treatments leading to the reduction of disclusion time for treating MFP would not be appropriate. However more controlled, large scaled study, which consider various occlusal factors, and quantification of symptoms using Helkimo index would be necessary in the future.

Bioleaching of Mn(II) from Manganese Nodules by Bacillus sp. MR2 (Bacillus sp. MR2에 의한 망간단괴의 생물용출)

  • Choi, Sung-Chan;Lee, Ga-Hwa;Lee, Hong-Keum
    • Korean Journal of Microbiology
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    • v.45 no.4
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    • pp.411-415
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    • 2009
  • Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$ was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual $MnO_2$ particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were $25\sim35^{\circ}C$, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75 ${\mu}m$. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212 ${\mu}m$ as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.

A Study on Estimation of Biomass, Stem Density and Biomass Expansion Factor for Stand Age Classes of Japanese Larch (Larix leptolepis) Stands in Gapyeong Area (가평지역 낙엽송림의 바이오매스와 영급별 줄기 밀도 및 바이오매스 확장계수 추정 연구)

  • Noh, Nam-Jin;Son, Yo-Whan;Kim, Jong-Sung;Kim, Rae-Hyun;Seo, Keum-Young;Seo, Kyung-Won;Koo, Jin-Woo;Kyung, Ji-Hyun;Park, In-Hyeop;Lee, Young-Jin;Son, Yeong-Mo;Lee, Kyeong-Hak
    • Journal of Korea Foresty Energy
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    • v.25 no.1
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    • pp.1-8
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    • 2006
  • This study was conducted to develope allometric equations and to estimate biomass, stem density, and biomass expansion factor for the three stand age classes (I-II, III-IV, and V-VI) of Japanese larch (Larix leptolepis) in Gapyeong area. Total dry weight (kg/tree) and aboveground biomass (ton/ha) were 57.8 and 71.1 for I-II class, 185.4 and 195.6 for III-IV class, and 1047.9 and 180.6 for V-VI class, respectively. Total above and belowground biomass (ton/ha) was 96.3 for I-II class, 265.7 for III-IV class, and 244.5 for V-VI class. The proportion (%) of stem to total biomass increased with stand age class and was 53.9 for I-II class, 55.7 for III-IV class, and 57.7 for V-VI class, respectively, while that of foliage decreased and was 7.1 for I-II class, 4.5 for III-IV class, 2.3 for V-VI class. Ratios of root to aboveground biomass were 0.35 for all age classes. Stem density ($g/cm^3$) differed between I-II class and III-VI class. Aboveground and total biomass expansion factors were 1.31-1.44 and 1.26-1.94. Our results showed that differences in stand density with stand age classes might influence allometric equation, stem density and ratios of aboveground biomass to stem biomass and total biomass to stem biomass (biomass expansion factors).

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Analysis of Prethrombotic States in Patients with Malignant Tumors

  • Cui, Lin;Sun, You-Hong;Chen, Jue;Wang, Lu;Liu, Jian-Jun;Zhou, Xiang-Rong;Ding, Jie;Liu, Xing-Xiang;Huang, Xin-En
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.13
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    • pp.5477-5482
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    • 2015
  • Background: This study aimed to investigate the incidence and risk factors for a prethrombotic state in patients with malignant tumors. Materials and Methods: Plasma d-dimer (D-D) in patients with malignant tumors was measured. Abnormal rates of D-D and possible risk factors like gender, age, type of tumor, and staging of tumor were analyzed. Results: Of 1,453 patients, 629 demonstrated plasma D-D abnormality (43.3%). The D-D abnormal rate of male patients (n=851, 43.5%) was not statistically significantly different from that for female patients (n=602, 43.0%) (p>0.05). D-D abnormal rate increased with age and was statistically significant among different age groups (p<0.05). Regarding staging of tumor, D-D abnormal rate in patients with phase I was 2.0%, 6.2% in phase II, 47.6% in phase III and 83.1% in phase IV, with statistically significant differences between phase III and II, as well as phase III and IV (p<0.01). Conclusions: A prethrombotic state was closely related to malignancy of tumors. The risk factors for a prethrombotic state include age and tumor stage.

A Comparative Study on Cross-cultural Complaining Behavior of South Korean and Chinese Consumers about Fashion Products (II) -Focused on Lifestyle and Personality- (한·중 패션제품 소비자 불평행동에 미치는 영향요인 분석 II -소비자의 라이프스타일과 성격을 중심으로-)

  • Lee, Okhee
    • Journal of Fashion Business
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    • v.22 no.1
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    • pp.56-70
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    • 2018
  • This study investigated if there are differences between the effects of lifestyle and personality on consumer complaining behavior between Korea and China. Sample subjects of this study were female college students of Korea(Jeollabuk-do and Jeollanam-do) and China(Yunnan). The questionnaire data from 780 college students were analyzed through the following statistical analyses: a reliability analysis, factor analysis, frequency, mean, and multiple regression analysis. The results of the study was as follows. First, the complaining behavior types of college students were divided into 4 factors: third party, breakaway behavior, compensation claim, and negative word of mouth. Second, significant differences were revealed between the dissatisfaction and the conditions of complaining behavior between Korean and Chinese consumers. Third, significant differences were found which were related to the effects of lifestyle and personality on types of consumer complaining behavior between Korea and China. Fourth, the complaining behavior factors of 'third party' and 'compensation claims' of Chinese consumers were higher than those of Korean consumers; however, the 'negative WOM' of Korean consumers were higher than those of Chinese consumers. Fifth, the lifestyle factors of 'fashion orientation, 'rational orientation' and 'activity orientation' of Chinese consumers were higher than those of Korean consumers. The 'achievement orientation' of Korean consumers was higher than that of Chinese consumers. And the personality factors of 'sense of responsibility' of Chinese consumers were higher than Korean consumers. Finally, 'openness' of Korean consumers were higher than Chinese consumers.