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새로운 보상 파라미터를 가지는 적응제어 기반 영구자석 동기전동기의 센서리스 속도제어
남기현(Kee-Hyun Nam),권영안(Young-Ahn Kwon) 대한전기학회 2013 전기학회논문지 Vol.62 No.7
Recently, sensorless controls, which eliminate position and speed sensor in a permanent magnet synchronous motor drive, have been much studied. Most sensorless control algorithms are based on the back-EMF and speed estimations which are obtained from the voltage equations. Therefore, the sensorless control performance is largely affected by the parameter errors of a motor. This paper investigates a novel adaptive control with the parameter error compensation for the speed sensorless control of a permanent magnet synchronous motor. The proposed parameter estimation is obtained from the d-axis current error between the real and estimated currents. The proposed algorithm is verified through the simulation and experimentation.
남기현(Kee-Hyun Nam),윤지섭(Ji-Sup Yun),이용상(Yong Sang Lee),정종주(Jong Ju Jeong),장항석(Hang-Seok Chang),정웅윤(Woong Youn Chung),박정수(Cheong Soo Park) 대한외과학회 2008 Annals of Surgical Treatment and Research(ASRT) Vol.74 No.3
Purpose: Postoperative hypocalcemia is a common complication of thyroidectomy. This study evaluated the incidence and risk factors for postoperative hypocalcemia after total thyroidectomy. Methods: There were 196 consecutive patients undergoing total thyroidectomy for thyroid cancer between September 2004 and February 2005 who were enrolled in this study. Patients were divided into two groups, those remaining normocalcemic (Group Ⅰ) and those who had hypocalcemia requiring treatment (Group Ⅱ). Group Ⅱ was subdivided into a transient hypocalcemic group (Group ⅡA) and a permanent hypocalcemic group (Group ⅡB). All groups were compared with regard to age, gender, histology, coexisting disease, T stage, bilateral lesions, primary total thyroidectomy versus secondary completion thyroidectomy, extent of lymph node dissection, and autotransplantation of the parathyroid gland. Results: Among all patients, 139 (71%) were in Group I, 54 (27.5%) in Group ⅡA and 3 (1.5%) in Group ⅡB. On the multivariate analysis for risk factors compared between Group Ⅰ and Group Ⅱ, the T4 stage was the most significant for the development of postoperative hypocalcemia. On the univariate analysis comparing factors between Group ⅡA and Group ⅡB, the T4 stage and a complete thyroidectomy were significantly related to the development of permanent hypocalcemia. Conclusion: The results of this study showed that the incidence of transient hypocalcemia, after total thyroidectomy, was 27.5%, while permanent hypocalcemia was detected in 1.5% of cases. The parathyroid glands should be preserved more carefully to avoid postoperative hypocalcemia in patients with high risk factors including T4 tumors and complete thyroidectomy procedures.
이잔디,남기현,임치영,장항석,정웅윤,박정수,Jandee Lee,M.D.,Kee-Hyun Nam,M.D.,Chi-Young Lim,M.D.,Hang-Seok Chang,M.D.,Woung Youn Chung,M.D. and Cheong Soo Park,M.D. 대한갑상선-내분비외과학회 2005 The Koreran journal of Endocrine Surgery Vol.5 No.2
Forgotten mediastinal goiter is an extremely rare disease. It is most often the consequence of the incomplete removal of a 'plunging' goiter, but it can sometimes be attributed to a concomitant, unrecongnized primary mediastinal goiter which is not connected to the thyroid. A primary mediastinal goiter(autonomous intrathoracic goiter) essentially caused by an abnormal embryonic development of the thyroid gland and a thyroid gland formation located in the thorax or the mediastinum. The differential diagnosis with ordinary recurrence was based on the absence of parenchymatous or vascular connections with the cervical thyroid gland. It is fed by local intrathoracic vessels and observed in the absence of previous thyroidectomy. Nevertheless, for primary mediastinal goiter, sternum-splitting incision will be required in most cases as troublesome mediastinal bleeding may occur which is difficult to control from a cervical collar incision. In this study we report a case of forgotten mediastinal goiter and review the various diagnostic and therapeutic problems posed by the condition. A number of possible solutions that can be implemented for this diasease are identified. (Korean J Endocrine Surg 2005;5:114-117)