• Title/Summary/Keyword: 굴곡각

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A Miniaturized and Band Rejection Characteristic of Bow-Tie Monopole UWB Antenna (보우-타이 모노폴 UWB 안테나의 소형화 및 대역 저지 특성)

  • Choi, Hyung-Seok;Choi, Kyoung;Hwang, Hee-Yong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.3
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    • pp.300-305
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    • 2012
  • In this paper, a miniaturized bow-tie monopole UWB antenna with band rejection characteristic is proposed. To miniaturize the proposed antenna, a perfect magnetic wall(PMW) condition is applied to primitive bow-tie monopole antenna. An uneven ground patch, a tapered feeding structure and a edge-chopped main patch are adapted for impedance matching. A quater-lambda slot resonator is inserted at main patch to prevent interference in UWB band from another band. The proposed antenna is fabricated on Taconic RF60-A substrate with relative permittivity of 6.15. The size of the proposed antenna is $30.0{\times}39.7mm^2$, which is only 45 % of the conventional bow-tie monopole antenna. The proposed antenna covers full UWB band with return losses less than -10 dB and has band stop characteristic in 5 GHz WLAN band. The maximum gains are within -1.0~5.0 dBi, the group delay variations are within 1.0 ns and the radiation patterns show directivity characteristics in x-y plane.

A research on improving signal to noise ratio for magnetic resonance imaging through increasing filling factor inside surface coil (자기공명 검사시 코일 내 filling factor 증가를 통한 신호대 잡음비의 향상에 관한 연구)

  • Choi, Kwan-Woo;Son, Soon-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5299-5304
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    • 2012
  • MRI signals are significantly reduced by the magnetic field inhomogenity result from human body itself being consisted of various materials like air, fat, muscle, bone and blood vessels. In this study we used silicon which is tissue equivalent to compensate wound body shapes. Objects were eight adults who do not have any special symptoms. Feet were scanned because of their complicated structures and consequently signal reduction occurs a lot. Thirty images were acquired from the middle of arcus pedis longitudinalis including five distal phalanges parallel to the line connecting metatarsal bone and phalanges. SNR data from bones and soft tissues were compared before and after sticking silion between toes and paired t test was performed. It was came out that SNR data from bone and soft tissue were both significantly higher after applying silicon on both T1 and T2 weighted images and it was statistically meaningful having positive corelation. As a result, this study dramatically increases SNR without affecting object by increasing the object volume inside the surface coil.

Irrigation Solutions in the Knee Arthroscopy - Comparison with Normal Saline and Lactated Ringer's Solution (슬관절 관절경 수술시 세척액 - 생리 식염수와 Lactated Ringer 용액의 비교)

  • Lee, Woo-Suk;Bae, In-Tak;Hur, Yun-Moo;Park, Won-Ki;Oh, Byung-Hak;Chung, Whan-Yong
    • Journal of the Korean Arthroscopy Society
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    • v.12 no.2
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    • pp.125-128
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    • 2008
  • Purpose: The object of this study is to compare the clinical results of noraml saline and Lactated Ringer's solution in the arthroscopic meniscus surgery on the knee. Materials and Methods: The study group included 64 patients who had an medial meniscus tear and received arthroscopic partial medial meniscectomy. The group I was normal saline group, which was used as an irrigation solution during operation. The group II was Lactated Ringer's solution group. We measured the visual analogue scale, painless active knee flexion angle, and the ratio of the knee swelling at postoperative one day for all patients. Results: The visual analogue scale and the painless active knee flexion angle were no significant differences in comparing with normal saline and Lactated Ringer's solution group. The ratio of the knee swelling in Lactated Ringer's solution group was significantly less than those of noraml saline group. Conclusion: Lactated Ringer's solution has an advantage of decreasing the knee swelling in the arthroscopic meniscus surgery on the knee.

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Effects of Cervical Joint Mobilization on the Forward Head Posture and Neck Disability Indexes (경부관절가동술이 두부전방자세와 경부장애지수에 미치는 영향)

  • Oh, Hyunju;Hwang, Byeongjun;Choi, Yoorim
    • Journal of the Korean Society of Radiology
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    • v.8 no.2
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    • pp.89-96
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    • 2014
  • This paper tries to examine whether the application of joint mobilization to subjects who have the forward head posture due to malalignment in the cervical joint has influence on posture changes and functions in the cervical joint. The subjects were 39 students from G University in Gyeongsangbuk-do. The cervical joint mobilization was applied to 20 subjects and not to 19. The students with a cervical lordosis angle of $21^{\circ}C$ or less, an anterior weight bearing (AWB) of 15mm or greater, and a cervical extension ROM of $70^{\circ}C$ or less in terms of radiography were selected as subjects under their voluntary agreement. The patients actively performed the joint mobilization slowly 8 times per session while therapists continuously applied sustained accessory glide to their painful joints 3 times per week for 4 weeks along with the cervical expansion and flexion in SNAGS among other Mulligan's (1995) techniques. The measurement was carried out in terms of radiographic inspection and neck disability indexes. As a result of the experiment, it turned out that the subjects with the forward head posture had changes in the cervical AWB and ARA, the ranges of expansion and flexion, and the NDI(Neck Disability Index) after the intervention for the experimental group by applying cervical joint mobilization. There were no changes observed in the control group. In conclusion, the application of joint mobilization turned out to have influence on the improvement of cervical joint postures, and craniocervical region functions.

Gait Analysis After Posterior Cruciate Ligament Reconstruction Using Fresh-Frozen Achilles Allograft (신선 동결 아킬레스 동종건을 이용한 후방십자인대 재건술 후 보행분석)

  • Chun, Churl-Hong;Cho, Jae-Deuk;Chun, Keun-Churl
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.8 no.2
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    • pp.76-82
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    • 2009
  • Purpose: The purpose of this study was to analyze the clinical result and the gait patterns for patients who had undergone the arthroscopic posterior cruciate ligament (PCL) reconstruction using Achilles allograft. Materials and Methods: Among the patient who had undergone the arthroscopic PCL reconstruction using fresh-frozen Achilles allograft between March 2004 to March 2005, we selected 12 patients who compliance to our rehabilitation program. Clinical result and gait analysis were carried out at 36 months postoperatively. There were measured by using range of motion (ROM), Lysholm knee score, Tegner activity score, IKDC score, posterior stress test, and posterior translation measured by using Telos stress arthrometer. Kinematic gait analysis was carried out using 3-dimensional gait analysis system. Results: The PCL reconstruction surgery yielded statistacally significant results in all of clinical evaluation. In gait analysis, the average knee flexion angle increased during stance phase and decreased during the swing phase, but was not statistically significant and there were no significant difference between both sides of their knees overall. Conclusion: Since there was no statistically significant difference between the injured and uninjured sides as a result of the gait evaluation of the patients who had arthroscopic reconstruction surgery on their PCL injured knee and conformed to the rehabilitation program, systemic and strict rehabilitation ought to be important in the reconstruction surgery.

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Development of Eggs, Larvae and Juvenile of the Korean Bullhead, Pseudobagrus fulvidraco (Richardson) reared in the laboratory (동자개의 형태발달과 성장특성)

  • Han, Kyung-Nam;Nam, Ki-Bong;Jeong, Choong-Hoon
    • Korean Journal of Ichthyology
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    • v.13 no.1
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    • pp.74-84
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    • 2001
  • The early developmental stages, growth and morphological changes of the Korean bullhead, Pseudobagrus fulvidraco, were studied from a series of reared specimens. Details of the early developmental stages are illustrated with special reference to morphological transformations. Egg and sperm of Korean bullhead were obtained from mature adults under hormonal treatment, fertilized artificially, and incubated in the aquarium. The incubation period of fertilized eggs was 55 to 66 hours at a temperature of 24.9${\pm}$0.34$^{\circ}$. Larvae were fed successively with Artemia salina and Daphnia magna for 2 to 15 days and artificial food after 20 days. Fertilized eggs were adhesive and spherical with a diameter of 2.04mm(n = 100). The mean total length of newly hatched larvae was about 4.92${\pm}$0.33 mm. Mouth opening occurred on one-day-old yolk-sac larvae, and initial feeding was observed on the third day after hatching. The morphological transitions from larvae to juvenile and juvenile to young stages occurred when the fish reached about 17 mm in total length (about 13days after hatching) and about 32 mm in total length (about 30 days after hatching), respectively. Many changes in proportion of body parts to total length were observed at about 7~8 mm and 30~32 mm, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. In comparing relative growth of each body part against total length, those characteristics related to head parts showed positive growth in the pre-larval stages, while those concerning mobile abilities showed positive growth in the post-larval stage.

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Measurement of Skin Dose for Rectal Cancer Patients in Radiotherapy using Optically Stimulated Luminescence Detectors (OSLDs) (광자극발광선량계(OLSDs)를 이용한 직장암 방사선치료 환자의 피부선량 측정)

  • Im, In-Chul;Yu, Yun-Sik;Lee, Jae-Seung
    • Journal of Radiation Protection and Research
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    • v.36 no.2
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    • pp.86-92
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    • 2011
  • This study used the optically stimulated luminescence dosimeters (OSLDs), recently, received the revaluation of usefulness in vivo dosimetry, and the diode detecters to measure the skin dose of patient with the rectal cancer. The measurements of dose delivered were compared with the planned dose from the treatment planning system (TPS). We evaluated the clinical application of OSDs in radiotherapy. We measured the calibration factor of OSLDs and used the percent depth dose to verified, also, we created the three point of surface by ten patients of rectal cancer to measured. The calibration factors of OSLD was 1.17 for 6 MV X-ray and 1.28 for 10 MV X-ray, demonstrating the energy dependency of X-ray beams. Comparison of surface dose measurement using the OSLDs and diode detectors with the planned dose from the TPS, The skin dose of patient was increased 1.16 ~ 2.83% for diode detectors, 1.36 ~ 2.17% for OSLDs. Especially, the difference between planned dose and the delivery dose was increased in the perineum, a skin of intense flexure region, and the OSLDs as a result of close spacing of measuring a variate showed a steady dose verification than the diode detecters. Therefore, on behalf of the ionization chamber and diode detecters, OSLDs could be applied clinically in the verification of radiation dose error and in vivo dosimety. The research on the dose verification of the rectal cancer in the around perineal, a surface of intense flexure region, suggest continue to be.

Effects of the Symmetric Upper Extremity Motion Trainer on the Motor Function Recovery after Brain Injury: An fMRI Study (뇌손상 후 운동신경기능 회복에 대한 대칭형 상지 운동기구의 효과: 기능적 뇌 자기공명영상 연구)

  • Tae Ki-Sik;Choi Hue-Seok;Song Sung-Jae;Kim Young-Ho
    • Progress in Medical Physics
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    • v.16 no.1
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    • pp.1-9
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    • 2005
  • The effect of the developed symmetric upper extremity motion trainer on the cortical activation pattern was investigated in three chronic hemiparetic patients using both fMRI and Fugl-Meyer test. The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer tests were performed every two weeks during the training. fMRI was performed at 3T scanner with wrist flexion-extension in two different tasks before and after the training program: the only unaffected hand movement (Task 1) and passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral SMC but increased in contralateral SMC. Task 2 showed cortical reorganizations in bilateral SMC, PMA and SMA. Therefore, it seems that the cortical reorganization in chronic hemiparetic patients can be induced by the training with the developed symmetric upper extremity motion trainer.

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Study on Lateral Flow Distribution and Momentum Analysis at Flood season and Neap tide of the Seokmo Channel in the Han River estuary (소조기 홍수시 한강하구 석모수로에서의 횡 방향 2차 흐름 및 운동량 분석)

  • Choi, Nak Yong;Woo, Seung-Buhm
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.6
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    • pp.390-399
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    • 2012
  • This research observed the cross section current of 7 survey lines in Seokmo Channel of Gyeonggi bay with a lot of freshwater inflow and S-shaped for 13 hours during flood season and neap tide. We indicated the distribution of the current velocity by comprehending the speed and direction of the current velocity of each line during maximum flood, ebb tide and observed the distribution of salinity. Moreover, in order to understand what lateral momentum causes the lateral flow in each survey line, we practiced the momentum analysis through the observation data. As a result, the lateral baroclinic pressure gradient force and vertical friction of the Seokmo channel during neap tide were the strongest, and this is why the flow by the distribution of salinity and stratification most often occurs. In north of the Seokmo channel, where have wide intertidal and a lot of freshwater inflow, the secondary circulation is caused by balance of lateral baroclinic pressure gradient force and other forces, and the vertical friction was strong in the lines with small depth. On the other hand, in the southern part of the Seokmo channel where the water is deep and the waterway is curved, the advective acceleration and centrifugal force become stronger by the geographical causes during ebb and the influence of fresh water. Therefore, the lateral flow in the Seokmo channel was caused by the distribution of the momentum that differs by location, depth, curve, etc.

Normal Range of Shoulder Motion and Fluoroscopic Analysis of Motion Fraction (정상인의 견관절 운동범위 및 방사선 투시기를 이용한 운동분율측정)

  • Choi Chang-Hyuk;Yun Gi-Hyun
    • Clinics in Shoulder and Elbow
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    • v.1 no.2
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    • pp.221-229
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    • 1998
  • We measured, with manual goniometer, the active and passive arc of motion of the shoulder in 31 healthy male subjects who were right-hand dominant and who ranged in age from twenty to thirty-one years. Among ten directions through the four motion plane, the range of motion on the dominant side were significantly smaller than those on the non-dominant side in the motion of six directions. We also measured the motion fraction of the glenohumeral and scapulothoracic movement using fluoroscope in 30-degree intervals of arm elevation in the scapular plane. The ratio of glenohumeral to scapulothoracic movement(θGH/θST) was 1.6 for the full range of motion in scapular plane. At the lower angles of abduction, scapulothoracic movement was slight compared with glenohumeral movement. The motion fraction of scapulothoracic joint was increased from 60-degree to 150 degree of arm angle especially between 120 to 150 degree. During arm elevation, scapula was also extended from 42 degrees to 20 degrees tilting as well as internal rotation. The measuring technique of glenohumeral to scapulothoracic movement(θGH/θST) with fluoroscopy could be applied to the simple radiographic measurement at the out-patient clinic in order to identify the pathology and recovery of shoulder motion after treatment.

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