http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
하근수(Keunsoo Ha) 대한전기학회 2009 전기학회논문지 Vol.58 No.11
A Low cost and variable speed brushless motor drive system with single switch per phase is presented. The motor drive is realized with a novel two-phase flux-reversal-free switched reluctance motor and a split AC two switch converter. The strategy of the controller and the converter for its realization are described. Comparisons between a split AC converter, asymmetric converter, split DC converter, single controllable switch converter, and N+1 converter are performed for its device rating, cost, switching losses and conduction losses, and converter efficiency. The split AC converter is analyzed and simulated to verify the characteristics of the converter circuitry and control feasibility and the simulation results are presented. The efficiency with various loads is numerically estimated and experimentally compared from viewpoint of subsystem and system in details. The focus of this paper is to compare the presented motor drive system to the asymmetric converter system throughout experiments and demonstrate single switch per phase converter having comparable efficiency as the asymmetric converter system.
하근수(KS Ha),박두철(DC Park),하옥근(OK Ha),정재훈(JH Chung) 대한산부인과학회 1969 Obstetrics & Gynecology Science Vol.12 No.8
The authors observed 29 cases of VDRL positive (Reactive) pregnant women during antepa- rtum care and treatment at Maryknoll Hospital Pusan Korea, for a period of one year from April 5, 1967 to April 4, 1968. Clinical observations were as follows: 1. The total number of pregnant women receiving antepartum care during this period was 673. Among these 673 pregnant women, receiving antepartum care during this period was 673. Among there 673 pregnant women, we found 29 patients with VDRL positive (reactive) serunm: percent positive ratio was 4.5 per cent ofthe entire group. 2. The average age of VDRL positive women was 28.3 years; the average age of the male partner was 33.9 years. 3. None of the 29 VDRL positive women knew that they had Syphilis; theree patients gave suggestive skin lesions. 4. Among the VDRL pisitive pregnant women: ....44.8 per cent had a past history of one or more premature deliveres ....24.1 per cent had a past history of one or more stillbirth ....34.5 per cent had had one or mere neonatal desths 5. In the VDRL postive group the average feral weight was 6 Ibs. 10 oz. and the range was from 3 Ibs. 12 oz. to 9 Ibs. 6 oz. 6. In the VDRL postive group, he average of pregnancy was 38.7 wks, the range from 30-44 weeks. 7. In almost all cases, the cord blood was VDRL reactive(positive) and therefore VDRL of the cord blood seems to be no further diagnostic value. 8. Only a single newborn infant(fromthe group of VDRL reactive mothers adequately treated with Penicillin) had minimal clinical evidence of congenital syphilis. In the non-treated or inadequately treated group, there were 2 stillbiths,and 3 neonatal deaths from among a total of 12 births. 9. Incidence of Prematuritywas 20 per cent in the VDRL positive group, while only 7.7 per cent in the VDRL negative group; the incidence of Prematurity with Stillbisth was 5.3per cent in the VDRL positive as comopared to 0.8 per cent in the VDRL negative group; the incidence of Neonatal Death was 15.7 per cent in the VDRL positive group as compared to no Neonatal Deaths VDRL negative group. As noted in above clinical observations, the incidence od Prematurity, Stillbirth and Neonatal Death was considerably higher in the VDRL positive (Reactibve) group as compared to that found in the VDRL Negative (Non-reactive) group.
하근수(Keunsoo Ha) 대한전기학회 2010 전기학회논문지 Vol.59 No.2
Low cost motor drives are being sought for high volume energy efficient home appliances. Key to the realization of such low cost motor drives is to reduce the power electronic converter in terms of its components, particularly the active devices, finding the motor with least complexity for manufacturing and a controller that could extract the desired performance from the machine and converter combination. These and other factors such as self-starting, speed control over a wide range and most of all the crowning aspect of a four quadrant operation with bare minimum number of controllable switch (or switches) remain as formidable challenges for low cost motor drive realization. In this paper, a four quadrant switched reluctance motor (SRM) drive with only one controllable switch is realized by using a two-phase machine. The theory and operation of the proposed four-quadrant SRM drive with the proposed control algorithm for its realization are described. The motor drive is modeled, simulated and analyzed to verify its feasibility for self-starting, speed control and for four quadrant operation and the simulation results are presented. Experimental results confirm the validity of the proposed control algorithm for four quadrant control of the SRM drive. The focus of the paper is mainly directed toward the control algorithm for realizing the four-quadrant operation of the two-phase SRM drive with a single controllable switch converter.
정재훈(JH Chung),하근수(KS Ha),박두철(DC Park),하옥근(OK Ha),배국환(KH Bae) 대한산부인과학회 1970 Obstetrics & Gynecology Science Vol.13 No.10
A case of cervical pregnancy recently admitted to Pusan Maryknoll Hospital was presented and a brief review of the literature on cervical pregnancy was made.