공간벡터 PWM의 과변조 영역에서 출력전압 선형화

배장호,김연충,원충연,최종묵,기상우,배기훈,Bae, Jang-Ho,Kim, Yuen-Chung,Won, Chung-Yuen,Choi, Jong-Mook,Gi, Sang-Woo,Bae, Gi-Hun 대한전자공학회 1999 電子工學會論文誌, S Vol.s36 No.11

본 논문은 6-스텝까지 인버터의 선형제어영역을 넓히기 위한 공간전압 변조방법의 선형화 기법에 대해 제안하였다. 이 방법은 인버터에서 발생시키고자 하는 전압을 연속모드에서는 보상각을 얻기 위해서 6스텝 모드를 포함하는 불연속모드에서는 불연속 스위칭이 이루어지도록 하는 유지각을 얻기 위해서 퓨리에 급수를 이용하고 있다. 이 각들의 근사화 수식들을 과변조 영역에서 기본파 전압을 보상하기 위해 사용하였다. 따라서, PWM 인버터 출력전압의 최대 활용과 선형 제어를 이룰 수 있다. This paper proposes a linearization technique for the space vector modulation method, which increases the linear control range of inverter up to the 6-step inverter. This method is based on fourier series expansion of the desired output voltage of the inverter to calculate the compensation angle in continuous switching mode and holding angle in discontinuous switching including the 6-step mode respectively. The approximation equation of these angles are used for compensation of fundamental voltage in overmodulation range. Therefore, it is possible to obtain the linear control and the maximized utilization of PWM inverter output voltage.

종설 : 급성관동맥 증후군과 취약성 경화반

배장호 ( Jang Ho Bae ),송인걸 ( In Geol Song ) 대한내과학회 2010 대한내과학회지 Vol.79 No.3

Acute coronary syndrome (ACS) consists of unstable angina, non-ST segment elevation myocardial infarction (NSTEMI), and STEMI. The pathology underlying ACS is acute thrombosis in a coronary artery, which is usually caused by plaque rupture in a mild stenotic lesion. A rupture-prone plaque is known as a vulnerable plaque (VP), although recently the definition of VP has been expanded to include rapidly progressive plaque. Although no single method can predict future cardiac events in mild stenotic lesions, there have been big advances in detecting VP, such as virtual histology-intravascular ultrasound and optical coherence tomography. These techniques look for thin cap fibroatheromas, which is the most common type of VP, characterized by a thin fibrous cap <65 μm, a large necrotic core, and marked macrophage infiltration of the fibrous cap. The recent concept of VP, the methods for detecting VP, and the treatment of VP are discussed. (Korean J Med 79:241-249, 2010)

Medical Therapy & Peri-procedural Medication

Jang-Ho Bae(배장호) 대한인터벤션영상기술학회 2009 대한인터벤션영상기술학회지 Vol.12 No.1

악성 식도협착에서 금속제 자가확장형 StreckerTM 인공식도관의 내시경 삽입술

배장호(Jang Ho Bae),강영우(Young Woo Kang) 대한내과학회 1995 대한내과학회지 Vol.49 No.6

N/A Objectives: Endoscopic intubation is well established as a cheap, durable, and prompt effective procedure for palliation of malignant dysphagia, and also have an advantage in short stay in hospital. However, with conventional plastic tube protheses, esophageal intubation continues to be plagued by high morbidity and mortality as well as limited effectiveness in the relief of dysphagia. We discribed an experience with metallic self-expanding StreckerTM esophageal stent placement in patients with malignant esophageal obstruction. Methods: From July 1993 to November 1994, twelve consecutive patients with severe dysphagia due to malignant esophageal obstruction were treated with metallic self-expanding StreckerTM esophageal stent(Boston Scientific®). Thirteen stents were placed in twelve patients. Results: 1) Marked reduction of dysphagia was noted in all patients the day after stent insertion, and most of the patients received a normal diet thereafter. Macroscopically obvious ingrowth of tumor through the stent mesh was seen at endoscopy in four patients at 1 to 5months after insertion of the stent. But, These stents were successfully recanalized with endoscopic balloon dilatation and second stent insertion, And then improvement has been sustained for the mean follow up duration, 28.5±17.7weeks. 2) These were several complications such as, chest pain(3patients) and bleeding(2patients) during stent placement, and tumor ingrowth(4 patients)and perforation(1patients) after stent placement. But all these complication were successfully treated with several managements such as esophageal ballon dilatation, second stent placement, and supportive care, except perforation. A case complicated by perforation was died of mediastinitis and sepsis four weeks after implantation, but caused by preimplantation esophageal balloon dilatation. 3) The mean survival duration(±SD) was 20.2±10,2 weeks and 37.4±18.6 weeks in six died and five survived patients, respectively. Conclusion: Endoscopic insertion of metallic self-expanding StreckerTM stent was a safe and effective procedure for palliative treatment of malignant esophageal strictures. However, newly designed stent should be developed to overcome tumor ingrowth.

다분절 경추 유합 및 내고정 수술결과

전우열,배장호,정병우,김성호,김오룡,최병연,조수호,Jeon, Woo-Youl,Bae, Jang-Ho,Jung, Byoung-Woo,Kim, Seong-Ho,Kim, Oh-Lyong,Choi, Byung-Yon,Cho, Soo-Ho 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.1

Objective : The purpose of the present study was to examine neurologic changes, fusion rate and degree of kyphosis from the surgical results of those patients who underwent multi-level anterior interbody fusion and internal fixation. Methods : Among 63 cases of the patients who received multi-level anterior interbody fusion and internal fixation in 5 years between 1995 to 1999 at the neurosurgery department, we performed a retrospective study in 52 cases that could be followed up with dynamic view imaging ; the results were compared and analyzed. The analysis was based on the results of history taking, physical findings and radiologic findings, and Odom criteria were used to classify those cases with neurologic changes. Results : Among those 52 cases in whom the follow-up was possible for at least a year and dynamic view imaging was possible, bone fusion was seen in 93% of the trauma cases and 95% in the non-trauma cases and overall bone fusion was observed in 94% of the cases. Bone fusion was seen in 93% of the autobone cases, 95% of the allobone cases, and 94% of the Mesh cases. Radiologic changes were observed by comparing the lateral view after surgery ; kyphosis was seen in 53% of the autobone cases, in 70% of the allobone cases, and in 35% of Mesh cases ; in 45% and 60% of the non-trauma cases and trauma cases, respectively ; and in 55% of the 2 level fusion cases and 46% of the 3 level fusion cases. Neurologic changes classified according to Odom criteria showed excellent result in 48% of all the cases, good in 23%, fair in 4%, and poor in 25%. Conclusion : Even those cases with multi-level fusion, a high fusion rate could be obtained by performing anterior interbody fusion and internal fixation ; those cases with kyphosis were related more with the presence or absence of posterior compartment injury rather than the fusion level ; and those trauma cases showed not much difference in the fusion rate compared with non-trauma cases but had a high possibility of kyphosis.

Hα 방출선을 통한 Be 항성 원반

안대건,배장호,이상각,신영우,고연경,강석철,Ahn, Dae-Gun,Bae, Jang-Ho,Lee, Sang-Gak,Shin, Young-Woo,Ko, Yeon-Gyung,Kang, Suk-Chul 한국천문학회 2007 天文學論叢 Vol.22 No.4

서울대학교의 61cm 망원경에 SGS 분광기를 부착하여 4개의 Be 항성에 대한 분광 관측을 수행하였다. 관측으로부터 얻은 각 항성의 $H{\alpha}$ 등가폭은 HD 5394가 $-26.4{\AA}$, HD 10516이 $-27.7{\AA}$, HD 200120이 $-10.2{\AA}$, HD 202904가 $-18.2{\AA}$이다. 이로부터 Grundstrom & Gies (2006)가 제시한 $H{\alpha}$ 방출선의 등가폭과 수소 방출선 영역의 크기 관계를 이용하여 구한 원반의 수소 방출선영역의 크기는 HD 5394가 $6.7{\pm}0.3R_{H{\alpha}}/R_s$, HD 10516이 $8.2{\pm}0.4R_{H{\alpha}}/R_s$, HD 200120이 $6.0{\pm}0.4R_{H{\alpha}}/R_s$, HD 202904가 $4.1{\pm}0.1R_{H{\alpha}}/R_s$이었다. HD 5394와 HD 10516에 대한 결과는 $H{\alpha}$ 간섭 관측으로부터 얻어진 결과와 약 20% 정도 차이가 났다. 항성의 광구에서 발생한 $H{\alpha}$ 흡수선의 등가폭을 정밀하게 보정하고, Grundstrom & Gies (2006)의 모형이 좀더 현실적으로 개선되며 정확한 항성 물리량 (유효온도, 원반 경사각, 원반 전체 크기)을 적용할 경우, 보다 정확한 원반크기를 구할 수 있을 것이다. 따라서 본 연구에서는 61cm 구경의 반사망원경과 범용의 중분산 분광기를 활용한 분광관측으로도 충분히 Be 항성의 원반 변화에 대한 연구를 수행할 수 있다는 것을 제시하고 있다. We have determined the disk size of Be stars by using $H{\alpha}$ emission. We observed spectra of Be stars with telescope in SNU, equipped with SB SGS (Santa Babara Self Guided Spectrograph) and CCD ST-8. The size of disk of Be stars was estimated with the Be star model of Grundstrom & Gies (2006). This study suggests that the medium resolution spectra taken with small telescope equipped with commercial spectrograph are useful to estimate the approximate size of the $H{\alpha}$ emitting disk around Be stars.

원자력 발전소 전기1급 케이블의 60년 사용에 대한 고찰

진석일(Sug-Il Jin),배장호(Jang Ho Bae) 대한전기학회 2004 대한전기학회 학술대회 논문집 Vol.2004 No.7

백서의 가역성 및 비가역성 뇌허혈 모형의 실험적 고찰

송광철,최병연,김성호,배장호,김오룡,조수호,Song, Kwang Chul,Choi, Byung Yon,Kim, Seong Ho,Bae, Jang Ho,Kim, Oh Lyong,Cho, Soo Ho 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.7

Objective : The purpose of our experimental study was to analysis the advantages and disadvantages in the reversible and irreversible cerebral ischemic models with rats by staining with Neutral Red(NR) solusion, 2% 2,3,5-triphenyltetrazolium chloride(TTC) and Hematoxylin & Eosin(H & E). Methods : We have measured the range of cerebral infarction in the rat to get a suitable ischemic model along the object of study with and without craniectomy. With craniectomy, 9 rats were sacrificed for irreversible cerebral ischemic model by means of ligation at proximal(group I) and distal(group II), and coagulation at proximal(group III) middle cerebral artery. Also, 6 rats were sacrificed for irreversible(group IV) and reversible(group V) cerebral ischemic model using nylon thread without craniectomy. The sizes of infarction were measured by staining the coronal sections of the brain with NR solusion, TTC and H & E. Results : There are no difference of physiological parameters comparing the each group. Cerebral infarction was not observed in group II, but it's volume was largest in group IV. Disadvantages of craniectomy group(I, II, III) are the long duration of operation and cortical damage by procedure. It's advantage is confirmation of the middle cerebral artery occlusion and cessation of blood flow through the operative microscope. In case of ischemic models using nylon thread (group IV, V), it is hard to identify the interruption or recirculation of blood flow through the middle cerebral artery, but the advantage is the simplicity of operative technique which reduces the operation time and minimizes the cerebral damage due to craniectomy. Therefore, it seems important to set up the reversible and irreversible ischemic models by carefully considering advantages and disadvantages listed above. Conclusion : TTC staining seems to be effective since it reflects the histological damage sufficiently and quickly. It is hoped that researches focused on ischemic penumbra, which became popular recently, will be further carried on with use of NR staining, optical microscope and electron microscope.

경접형골동으로 수술한 뇌하수체 선종의 치료성적

전우열,김오룡,김성호,배장호,최병연,조수호,Jeon, Woo-Youl,Kim, Oh-Lyong,Kim, Seong-Ho,Bae, Jang-Ho,Choi, Byung-Yon,Cho, Soo-Ho 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.11

Objective : Transsphenoidal approach(TSA) has been used as useful operative method for pituitary tumor but is still controversal in case of cavernous sinus invasion or severe suprasellar extension. This study was performed to evaluate the surgical result, recurrence, effect of adjuvant treatment, especially in cases of suprasellar extension or cavernous sinus invasion. Material and Methods : We studied 56 cases of surgically treated pituitary adenoma that we were able to follow up, treated by TSA from 1993 to 1998. There were 24 cases of suprasellar extension and 11 cases of cavernous sinus invasion. The medical records and radiological findings were reviewed. Surgical results including hormonal function and recurrence rates were analyzed according to extent of tumor invasion. Mean follow-up period was 19.1 months. Results : Tumors with suprasellar extension were removed totally in 54%, whereas total tumor removal was possible only in 38% with cavernous sinus invasion. Overall of recurrence rate was 14% and recurrence rate was 25% in suprasellar extension and 9% in cavernous sinus invasion. In cases of both suprasellar extension and cavernous sinus invasion, tumors that were treated by TSA and radiation showed recurrence rate of 7%, whereas those treated by surgery alone showed 28% of recurrence. Conclusion : Transsphenoidal approach is safe and useful operative method for pituitary adenoma and adjuvant therapy including radiation therapy is effective means to decrease the recurrence in cases of suprasellar extension or cavernous sinus invasion.

재발하였거나 수술적 제거가 불가능한 뇌수막종에 대한 Hydroxyurea 치료 - Preliminary Report -

이정환,김오룡,김성호,배장호,최병연,조수호,Lee, Jeong-Hwan,Kim, Oh-Lyong,Kim, Seong-Ho,Bae, Jang-Ho,Choi, Byung-Yon,Cho, Soo-Ho 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.1

1988년 1월부터 1997년 12월까지 본 교실에 내원하여 뇌수막종으로 진단받고 수술요법을 실시한 87례 중, 완전제거 후 재발한 경우와 부분적 절제후 방사선 치료를 받은 4례를 대상으로 hydroxyurea를 이용해 치료한 결과를 분석하였다. 남자가 1례, 여자가 3례이었으며 연령 분포는 23세에서 55세였다. 조직학적으로 3례가 meningothelial type이었으며 1례는 angiomatous type이었다. 3례에서 소뇌교각부에 발생하였으며 1례에서 해면정맥동에 발생하였다. 모든 환자들은 수술적 치료를 시행받았으며 3례의 환자에서 방사선 치료를 시행하였다. Hydroxyurea를 20mg/kg/day용량으로 투여하였으며 평균 추적관찰기간은 34개월이었다. 치료기간중 4례에서 종양이 줄어든 예는 없었으나 종양이 성장하지는 않았다. 삼차신경통 증상이 있던 1례는 증상 호전 되었으며 수술적 치료를 3차례 받았던 1례에서 두개골절제부위에 팽창되어 있던 뇌는 축소되어 두개강내로 복귀되었다. 혈액학적 부작용으로 백혈구 수치가 1례에서 감소되었으나 2주정도 복용을 중단한 후 다시 수치는 회복되었고 다른 심각한 부작용은 나타나지 않았다. 저자들은 뇌수막종 환자중, 수술후 재발한 경우와 불완전 제거를 시행한 경우 보조적 치료방법으로 hydroxyurea의 사용하여 종양크기의 감소는 없었으나 성장을 억제할 수 있었으며 앞으로 오랜 기간 추적관찰과 많은 증례에 대한 분석을 함으로써 뇌수막종 치료의 보조 방법으로 hydroxyurea를 이용할 수 있을 것으로 생각된다. Objectives : The present study was performed to analyze results of hydroxyurea treatment for unresectable and recurrent meningiomas as adjuvant chemotherapeutic agent. Material and Methods : Among 87 cases of meningioma patients who treated surgically between Jauary 1988 and December 1997 in our department, unresectable and recurrent cases were 4 cases. Histologically, 3 cases were meningothelial type, 1 case was angiomatous type. Tumor orgin was cerebellopontine angle(CPA) in 3 cases, cavernous sinus in 1 case. Three of 4 cases received radiation treatment. All patients received a daily dosage of 20mg/kg/day of hydroxyurea. Hematological monitorning was performed monthly and tumor measurement was assessed by MR imaging before treatment and every 6 months. Mean follow-up period was 34 months. Rerults : All cases showed no enlargement of tumor mass without any shrinkage. Trigeminal neuralgia in 1 case was improved and external herniation of brain on craniectomy site in 1 case was shrunken. None of the patients had any serious side effects. White blood cell count fell below $3000/{\mu}l$ in 1 case, but recovered 2 weeks later with cessation of medication. Conclusion : Hydroxyurea stopped cell growth by triggering the apoptotic cascade. Our preliminary data indicate that hydroxyurea provides adjuvant medical treatment in patients of unresectable and recurrent meningiomas