• 한국정보통신학회논문지
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• 제10권11호
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• pp.1940-1945
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• 2006

본 논문에서는 S밴드(24 GHz)와 C밴드(4-8 GHz)에서 사용가능한 비동심원 복사구조와 저 임피던스 급전구조를 갖는 소형 광대역 원형 링슬롯 안테나를 제안하였다. 본 안테나는 유전율 4.3, 두께 1mm의 기판을 대상으로 해석되었다. 제안된 안테나의 측정된 임피던스 대역폭은 $118%(S_{11}{\leq}-10dB)$이므로 기존의 원형 링슬롯 안테나보다 훨씬 광대역이다. 또한 주요 설계변수들을 변화시켰을 때 변경되는 안테나의 특성을 연구함으로써 최적화설계에 도움이 되도록 하였다.

• 전기학회논문지
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• 제61권1호
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• pp.110-116
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• 2012

This paper proposes a new diversity antenna which is the base of MIMO, tunable and reconfigurable antennas. The antenna has a small size and high inter-antenna isolation resulting from the compact radiating element comprising a meandered line and an open-loop combined in one limited uniplanar space and a modified T-shaped decoupling structure, respectively. In a WiMAX band, the radiating element and the entire antenna are $0.092{\lambda}$ and $0.2216{\lambda}$ in size, which shows effective size-reduction and the gain and efficiency of the proposed antenna attached to the ground of a handheld device are 3.7dBi and 56% acceptable to the industrial standard.

• Journal of Korean Neurosurgical Society
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• 제41권6호
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• pp.418-420
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• 2007

Discal cyst is a very rare lesion that can result in refractory low back pain and leg radiating pain. Because they are so uncommon, their exact origin and pathophysiology are still unknown. A 31-year-old man visited our institute due to low back pain and severe left leg radiating pain. Magnetic resonance images [MRI] revealed spherically shaped extradural cystic lesion at L2-L3 level. Computed tomography [CT] discography demonstrated obvious communication between the intervertebral disc and the cyst. The patient underwent posterior decompression and excision of cyst. The symptoms were remarkably improved immediately after surgery.

• 전기전자학회논문지
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• 제25권2호
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• pp.408-411
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• 2021

This paper presents a new reflectarray antenna capable with 1-bit switchable capability for W-band beamforming network. The proposed antenna has been optimized using two unit-cells with sizes of 1.0 mm and 1.3 mm to form a total number of 193 radiating elements on a square aperture surface of length 30 mm. These radiating elements are spaced 0.5 wavelengths apart and fed by a 15 dBi pyramidal horn antenna as the feed antenna placed 53 mm away from the aperture center. The proposed reflectarray achieves a realized peak gain of 22.52 dBi, a half-power beamwidth of 5.1° in both E- and H-planes at the test frequency of 80 GHz and operates over a wide bandwidth from 74 GHz to 90 GHz.

• 한국자동차공학회논문집
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• 제16권1호
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• pp.45-51
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• 2008

This paper presents theoretical and experimental analysis on the characteristics of the power spectrum of electormagnetic waves radiating from the spark plug and their cables of a distributorless ignition system. The theoretical study was conducted applying the microwave transmission line theory and the antenna theory. The experimental works were carried out to measure the standing wave ratio(SWR) and the radiation power spectrum of this system. As a result, it has been found that a spark plug and its cable is working as a monopole antenna radiating elelctromagnetic waves. Because of its similar structure to a monopole antenna, the envelope of radiation power spectrum distribution has a bell shape which can be obtained from a monopole antenna operating as a series resonant circuit. The frequency characteristics from the SWR measurements show a similar frequency characteristics of power spectrum of the system studied. Also, it has been found that the density of the power spectrum of the system fitting a long time used spark plug is higher than that of fitting a new spark plug.

• Journal of Korean Neurosurgical Society
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• 제40권4호
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• pp.256-261
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• 2006

Objective : The goal of this study was to establish the benefit and prognostic factors of lumbar medial branch block[MBB] for low back pain. Methods : A retrospective analysis was based on the data obtained from 281 patients with low back pain, who visited our hospital between January 2001 and November 2004. Pain relief was evaluated at 2 weeks, 1 month and 3 months. The authors analyzed the results of MBB according to the patient's age, sex, symptom duration, pathologic condition, and presence of radiating pain. Results : Two hundred eighty one patients had sprain [151]. lumbar fracture [27], spinal stenosis [50], herniated lumbar disc [24] acute post-operative pain [8], and chronic post-operative pain [21] with success rate of 63.6%, 59.3%, 26.0%, 25.0%, 87.5% and 42.9%, respectively. The effects of MBB in sprain, lumbar fracture, and acute post-operative pain were significantly better than those in stenosis, herniated lumbar disc and chronic post-operative pain patients. The patients in young age group [<60 years], with short symptom duration [<6 months] and without radiating pain showed good response to lumbar MBB. Conclusion : The lumbar MBB appears to be safe and effective for low back pain in certain selected patients. Good prognostic factors were low back pain without surgical conditions and radiating pain, with short symptom duration [<6 months], and in relatively young age [<60 years] group.

• 한국전자파학회논문지
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• 제22권1호
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• pp.81-88
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• 2011

본 논문은 비선형 소자 탐지기용 광대역 스파이럴 안테나의 설계를 제안한 것이다. 방사면 위의 스파이럴 소자뿐만 아니라 방사면 중심부에 위치한 방사 소자인 타원형 패치가 스파이럴 안테나의 광대역화를 위하여 설계되었다. 또한, 그라운드면 위에 스파이럴 슬릿을 삽입함으로써 다중 공진을 일으키는 안테나 그라운드 구조가 제안되었다. 제안된 안테나의 높은 지향성과 고이득을 실현하기 위해, Fr4-epoxy로 만든 캐비티 벽과 금속캡이 설계에 고려되었다. 그 결과, 금속 캡을 가진 안테나의 계산된 이득은 금속 캡이 없는 안테나의 이득과 비교하여 약 3 dBi 개선되었으며, -z축 방향으로의 측정된 주 빔 지향성도 계산 결과와 잘 일치하였다. 설계 주파수 대역에서 측정된 축비도 -z축을 기준으로 ${\pm}45^{\circ}$의 범위에서 원편파를 만족하였으며, 예상과 잘 일치하였다.

• 동의생리병리학회지
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• 제30권1호
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• pp.66-72
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• 2016

This retrospective observational study was aimed to assess that Shinchubogun-tang (Shenzhuibujian-tang ; SBT) improves the symptoms related to lumbar disc herniation. We analyzed the medical records of 36 patients, who were satisfied with inclusion and exclusion criteria. The patients were diagnosed with lumbar disc herniation and prescribed with SBT in addition to Korean medical common treatments at Dunsan Korean Medicine Hospital of Daejeon University from January 1st, 2013 to November 30th, 2015. The effects of SBT was evaluated by comparing before and after taking SBT through 0-10 visual analogue scale(VAS) of the symptoms including lower back pain, radiating pain, and lower extremity numbness. The average period of common Korean medicine treatment before SBT prescription was 9.78 days and then the patients received SBT along with common Korean medicine treatment for 13.17 days on average. SBT plus common korean medicine treatment group significantly decreased VAS score of lower back pain from 5.40±1.62 to 3.28±1.70 (p<0.01), radiating pain from 5.60±1.42 to 2.35±1.79 (p<0.01), lower extremity numbness from 5.77±1.52 to 2.55±1.85(p<0.01). These results demonstrated that SBT might have a potential on improvement of lumbar disc herniation by reducing the symptoms of lower back pain, radiating pain, and lower extremity numbness.

• 척추신경추나의학회지
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• 제8권1호
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• pp.15-26
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• 2013

Objectives: The purpose of this study is to find out the relationship between lumbar lordotic angle and low back pain patterns. Methods: We randomly selected the 1191 patients (595 males, 596 females) who have visited Bu-Chun Jaseng Hospital of Korean Medicine with low back pain. We have taken lumbar x-ray films and measured their lumbar lordotic angle, the angle formed between L1 superior margin and S1 superior margin. We investigated 1191 patients' low back pain patterns(date of occurence, existence of radiating pain, trend of increasing pain with lumbar extention and flexion, trend of increasing pain with standing and sitting positions) and analysed the relationship between lumbar lordotic angle and low back pain patterns. Results: 1. The lumbar lordotic angle of the acute phase patient is more straight than the chronic one. 2. The lumbar lordotic angle of the patients with radiating pain is more straight than the patients without radiating pain. 3. At acute phase, the lumbar lordotic angle of the patients with increasing pain from lumbar extention is more straight than those with increasing pain from lumbar flexion. 4. At chronic phase, the lumbar lordotic angle of the patients with increasing pain from lumbar flexion is more straight than those with increasing pain from lumbar extention. Conclusions: There was a significant correlation between lumbar lordotic angle and low back pain.

• Journal of Acupuncture Research
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• 제27권5호
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• pp.79-87
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• 2010

Objectives : This study was designed to evaluate the effects of treatment of HIVD patients with lower back pain, lower limb radiating pain and restricted on SLRT by the Sa-Am acupuncture. Methods : From March 2010 to July 2010, thirty HIVD patients who admitted to Cheonan oriental medical hospital in Daejeon university were divided into two groups. Group I was treated by Sa-Am acupuncture Banggwangjeonggyeok and general acupuncture, Group II by general acupuncture. We evaluated the treatment effect of each group with the Visual Analog Scale(VAS), Oswestry Disability Index(ODI), SLR test, dividing two period(from admission day to third day after admission and from third day to sixth day after admission). Results : 1. Group I is more effective than Group II in early pain and reducing rate of pain. 2. Group I is more effective than Group II in ODI score reducing rate from admission day to third day after admission, but there was no significant difference between the two groups from third day to sixth day after admission. 3. Group I is more effective than Group II in early SLR test improvement rate. Conclusions : Sa-Am acupuncture Banggwangjeonggyeok on HIVD patients with lower back pain, lower limb radiating pain and restricted on SLR test was effective in reducing pain and improving SLR test.