• Title/Summary/Keyword: cross-sectional area

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Stability Analysis ofn HTS Current Lead with Constant Safety Factor (안전율이 일정한 초전도 전류도입선의 안정성해석)

  • Seol, Seoung-Yun
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.2
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    • pp.15-19
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    • 2000
  • The stability of variable cross-sectional area HTS current lead is considered. The cross-sectional area is varied to have a constant safety factor which is defined as the ratio of operating current and critical current of superconductor. As the constant area HTS lead, the variable cross-sectional area HTS lead also has three steady states above the bifurcation point and only one steady state below the bifurcation point. The temperature profiles and current sharing ratios for each steady state are calculated. The heat dissipation into cryogenic system for super-conducting, intermediate, and upper states are compared. For Bi-2333 sheathed with silver-gold alloy 2m length of current lead, and the maximum temperature of upper state seems to be burn-out free below 5m length.

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Effect of Tube Area on the Impulse Wave Discharged from the Exit of Tube (관출구로부터 방출되는 펄스파에 미치는 관단면적의 영향)

  • Shin, Hyun-Dong;Lee, Young-Ki;Kim, Heuy-Dong
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.544-549
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    • 2003
  • When a shock wave arrives at an open end of tube, an impulse wave is discharged from the tube exit and causes serious noise and vibration problems. In the current study, the effect of the cross-sectional area of tube on the impulse wave is numerically investigated using a CFD method. The Harten-Yee's total variation diminishing(TVD) scheme is used to solve the axisymmetric, two-dimensional, unsteady, compressible Euler equations. With three different cross-sectional areas of tube, the Mach number of the incident shock wave $M_{s}$ is varied between 1.01 and 1.5. The results obtained show that the directivity and magnitude of impulse wave strongly depend upon the Mach number of incident shock wave and are influenced by the tube area. It is also known that the tube cross-sectional area significantly affects the magnitude of impulse wave at or near the tube axis.

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Carpal Tunnel Syndrome in Stroke Patients According to the Degree of Spasticity in Median Nerve Cross-Sectional Area and Nerve Conduction Velocity and Comparison of Upper Extremity Function (수근관증후군 뇌졸중 환자에서 경직정도에 따른 정중신경 단면적과 신경전도속도 및 상지기능의 비교)

  • Kim, Tae-Gon;Jung, Dae-In;Kim, Kyung-Yoon
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.288-296
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    • 2013
  • The purpose of this study were carpal tunnel syndrome in stroke patients according to the degree of spasticity in the median nerve cross-sectional area, nerve conduction velocity, and to evaluate differences in upper extremity function. The subjects of this study was in adult patients with stroke 42 patients from 21 patients CTS group and 21 patients Non-CTS group were selected. Measurement of median nerve-cross sectional area, nerve conduction velocity, GST, FMAS, CTS-FSS was measured. The study results were each group between the unaffected side and the affected side CTS and Non-CTS group in each grade between groups unaffected side(p<.001), and affected side(p<.001) median nerve-cross sectional area, median motor and sensory nerve onset latency, there was a statistically significant difference. CTS and Non-CTS group between groups in each grade GST(p<.05), FMAS(p<.05), CTS-FSS(p<.001), there was a statistically significant difference. In this study, the carpal tunnel pathokinesiology ever presented by the contents of upper extremity functional training in stroke patients is one of the information that you need to consider when presented.

Cone Beam Computed Tomography Analysis of Mandibular Anatomical Variation in a Patient with Facial Asymmetry (안면 비대칭 환자에서 Cone Beam Computed Tomography를 이용한 하악골 해부학적 변이의 분석)

  • Park, Seong-Won;Oh, Sung-Hwan;Lee, Jae-In
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.34 no.1
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    • pp.34-40
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    • 2012
  • Purpose: The study was performed to compare patients with anatomical variations in facial asymmetry with patients in the normal range using cone-beam computed tomography (CBCT) and to take the preoperative condition into consideration in the case of a sagittal split ramus osteotomy (SSRO). Methods: The study was conducted on 46 adult patients composed of 2 subdivided groups, an asymmetry group (n=26) and a symmetry group (n=20). The asymmetry group was divided between patients with hemimandibular hyperplasia (HH, n=8) and hemimandibular elongation (HE, n=18). Using cross-sectional computed tomography images, the thickness of cancelleous bone in the buccal area of the mandible, thickness of buccal cortex in the buccal aspect of the mandible, thickness of cancellous bone in the inferior aspect of the mandible, thickness of buccal cortex in the inferior aspect of the mandible, and cross-sectional surface area of the mandible were measured. Results: In the asymmetry group, the cross-sectional area of the mandible including the inferior alveolar nerve positioned on the affected side was significantly different from the symmetry group. Thickness of cancelleous bone in the buccal aspect of the mandible, thickness of cancelleous bone in the inferior aspect of the mandible, and cross-sectional surface area of the mandible in the affected site of hemimandibular hyperplasia was significantly smaller than in the symmetry group. Conclusion: The inferior alveolar nerve runs lower and in a more buccal direction and shows a smaller cross-sectional surface of the mandible in the hemimandibular hyperplasia patients with asymmetry.

Image Analysis of the Luster of Fabrics with Modified Cross-section Fibers

  • Shin Kyung In;Kim Seong Hun;Kim Jong Jun
    • Fibers and Polymers
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    • v.6 no.1
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    • pp.82-88
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    • 2005
  • We have investigated the luster of modified cross-sectional fiber fabrics as one of the essential quality estimates for clothing development. We have confirmed an objective evaluation method, and have determined the experimental luster char­acteristics of modified cross-section fibers. The cross-section of the fibers in a fabric affects the appearance of a textile. We used the image analysis method to investigate the luster to determine the critical factors influencing the appearance of modi­fied cross-section fiber fabrics. For similarly structured textiles in a component fabric, clear differences were observed in the fabric weave, density, percentage, and total area of blobs, which is image region. Color played a decisive role in the luster of the textiles, and luster was not significantly influenced by the modified cross-section fabric weave. In addition, the degree of luster did not increase in the order plain to twill to satin for modified cross-sectional fiber fabrics. All the split-type microfi­bers exhibited higher numerical luster values (percentage of pixels, and number and total area of blobs) than sea-island microfibers did. The degree of luster of the modified cross-sectional fiber fabrics was not high at specular reflection angles.

Prediction Model of the Exit Cross Scetional Shape in Round-Oval -round Pass Rolling

  • Lee, Young seog;Gert Goldhahn
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.1
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    • pp.87-93
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    • 2001
  • A reliable analytic model that determines the exit cross sectional shape a workpiece(material) in round-oval (oroval-round) pass sequence has been developed. The exit cross sectional shape of an outgoing workpiece is predicted by using the linear interpolation of the radius of curvature of an incoming workpiece and that of roll groovw to the roll axis direction. The requirements placed on the choice of the weighting function were to ensure boundary conditions specified. The validity of the analytic model has been examined by not rod rolling experiment with the roll gap and specimen size changed. The exit cross sectional shape and area of the workpiece predicted by the proposed analytic model were good agreement with those obtained experimentally. We found that the analytic model has not only simplicity and accuracy for practical usage but also save a large amount of computational time compared with finite element method.

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Cross-sectional study of the mandibular body in patients with facial asymmetry (안면 비대칭환자의 하악골체부의 시상 단면에 관한 연구)

  • Lee, Jae-Yeo;Kim, Yong-Il;Hwang, Dae-Seok;Kim, Yong-Deok;Shin, Sang-Hun;Kim, Uk-Kyu;Chung, In-Kyo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.37 no.2
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    • pp.109-113
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    • 2011
  • Introduction: To correct the facial asymmetry by mandibular jaw surgery, it is important to know the anatomy of the mandible including the mandibular canal positioning of patients with facial asymmetry. This study was performed to evaluate the differences in the cross-sectional surface in the body of the mandible between the deviated side and opposite side in patients with facial asymmetry. Materials and Methods: The study was conducted on 37 adult patients composed of 2 groups, the asymmetry group (n=20) and non-asymmetry group (n=17). Using the cross-sectional computed tomography (CT) images, the distance from the buccal aspect of the mandibular canal to the outer aspect of the buccal cortex, distance from the buccal aspect of the mandibular canal to the inner aspect of the buccal cortex, distance from the inferior aspect of the mandibular canal to the inferior border of the mandible, thickness of the mandible, and cross-sectional surface area of the mandible were measured in each side of the mandible Results: The cross-sectional area of the mandible including the mandibular canal positioning in the deviated side was not statistically different from the opposite side in the asymmetry group. Only the distance from the inferior aspect of the mandibular canal to the inferior border of the mandible in the ramus area of the deviated side was significantly longer than opposite side. On the other hand, the bucco-lingual width of the asymmetry group was thinner than the non-asymmetry group. Conclusion: The cross-sectional area including the mandibular canal of the mandible did not appear to be modified by the facial asymmetry.

The Effect of Mandibular Anterior Repositioning on the Upper Airway Volume (하악의 전방 이동이 상부기도의 용적에 미치는 영향)

  • Choi, Jae-Kap;Kee, Woo-Cheon;Kang, Duk-Sik
    • Journal of Oral Medicine and Pain
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    • v.24 no.1
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    • pp.69-80
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    • 1999
  • OBJECTIVES: This study was designed to measure the minimal cross-sectional areas and volumes of the pharynx in snoring patients and normal subjects and to see if there is an increase in the minimal cross-sectional areas and volumes of the pharynx with advancement of the mandible. METHODS: The pharyngeal computed tomography and 3-dimensional reconstruction were used to measure the cross-sectional areas and volumes of the nasopharynx, oropharynx, and hypopharynx with the jaw in normal position and in protrusive position in 7 patients with snoring and 7 control subjects while they were awake. RESULTS: The oropharynx was revealed to have the most narrow site in the pharynx and there was a tendency for the snorers to have a smaller nasopharyngeal and oropharyngeal cross-sectional area than normal subjects but not statistically significant. There were no significant differences in the volumes of the nasopharynx and oropharynx between the two groups. With advancement of the jaw the minimal cross-sectional area of oropharynx was significantly increased, and the volume was also increased but not significantly. The minimal cross-sectional areas and volumes of nasopharynx as well as hypopharynx were not significantly influenced by the advancement of the mandible. CONCLUSIONS: There was a tendency for snorers to have a smaller oropharynx than normal subjects and the oropharyngeal lumen was increased with the advancement of the mandible in both snorers and normal subjects.

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Effect of regular exercise during recovery period following steroid treatment on the atrophied hindlimb muscles induced by steroid in rats (스테로이드 치료 후 회복기의 규칙적인 운동이 쥐의 스테로이드 유발성 위축 뒷다리근에 미치는 영향)

  • Choe, Myoung-Ae;Byun, Young-Soon;Hwang, Ae-Ran;Kim, Hee-Seung;Hong, Hae-Sook;Choi, S-Mi;Seo, Wha-Sook;Lee, Kyung-Sook;Park, Mi-Jung;Shin, Gi-Soo;An, Gyeong-Ju;Lee, Yoon-Kyoung;Im, Ji-Hae
    • Journal of Korean Biological Nursing Science
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    • v.4 no.1
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    • pp.85-99
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    • 2002
  • This study was conducted to determine whether low intensity regular exercise following steroid treatment could attenuate steroid-induced muscle atrophy. Thirty-eight Sprague-Dawley rats weighing $165{\sim}175g$ were divided into six groups ; control group(C), dexamethasone administration group(D), sedentary normal saline administration group(C+Se), exercise after normal saline administration group(C+Ex), sedentary group after dexamethasone administration(D+Se), exercise group after dexamethasone administration(D+Ex). Either dexamethasone(5mg/kg) or normal saline was injected for 7days accordingly. Exercise was started at 10m/min on the $10^{\circ}$ grade treadmill and gradually increased up to 15m/min by the 7th day for 60minutes/day($20min{\times}3$). The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSS WIN 9.0 program. Body weight, muscle weight and myofibrillar protein content of both plantaris and gastrocnemius, Type I, II muscle fiber cross-sectional area of plantaris, and Type II muscle fiber cross-sectional area of gastrocnemius in D group were significantly lower than those of C group(p<0.05) respectively. Hindlimb muscle weight, myofibrillar protein content of both plantaris and gastrocnemius. Type I muscle fiber cross-sectional area of soleus and Type I, II muscle fiber cross-sectional area of plantaris in D+Ex group tended to increase compared to those of D+Se group. Myofibrillar protein content of both plantaris and gastrocnemius, Type I muscle fiber cross-sectional area of plantaris in D+Ex group tended to increase compared to those of C+Se group. Based on these results, it is suggested that regular low-intensity exercise during recovery period after steroid treatment might facilitate the recovery from steroid-induced muscle atrophy.

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Studies on Quantitative Analysis of Salivary Gland using Computed Tomography (전산화단층사진을 이용한 타액선의 정량분석에 관한 연구)

  • Lee Sang-Chul;Lee Sam-Sun;Heo Min-Suk;Choi Soon-Chul;Park Tae-Won;You Dong-Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.1
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    • pp.209-221
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    • 1999
  • Purpose: The purpose of this study was to calculate the size and CT number of both normal parotid and submandibular gland. and evaluate their relation to sex, age and obesity using computed tomography. Materials and Methods: The computed tomography was performed parallel to the Frankfurt plane in 46 subjects with healthy salivary gland. The subjects were divided into the three groups (young, middle. old) according to their ages. The size of salivary gland was determined as maximum cross-sectional area and the CT number of salivary gland was determined as the mean CT number of three ROI's. The body mass index was calculated from weight and height. Results: The mean maximum cross-sectional area was 7.79(±1.25)cm² on parotid gland and 4.12(±0.83) cm² on submandibular gland. The mean CT number was -4.43(±23.87) HU on parotid gland and 50.01(±15.63) HU on submandibular gland. There was decreasing pattern of the maximum cross-sectional area of submandibular gland and the CT number of both parotid and submandibular gland according to age(p<0.05). As the body mass index increased. the maximum cross-sectional area of parotid gland increased and CT number of both parotid and submandibular gland decreased(p<0.05). The maximum cross-sectional area of submandibular gland in male was larger than that in female(p<0.05). As the maximum cross-sectional area and CT number of left salivary gland increased. those of right gland increased(p<0.05). Conclusion : Intra-individual differences in salivary gland size and CT number is considered in the age and individual obesity.

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