(A) comprehensive study on the health needs and health care in Seoul

/박사During the last decade since the liberation in 1945, Korea, unfortunately, has not had enough political and social stability to study her nationwide health needs and the problems in its care. Most of the administrative and educational measures taken in the field of public health and medical care have been temporary emergency one : or because of traditional inertia, blindly imported foreign systems have been followed. In order to attain our final goal of providing best-quality comprehensive medical care for all people who need it and at minimum cost : We need an adequate and proper plan, set up on the basis of understanding the health needs at both local and national levels. The principal purpose of this study, therefore, were to obtain the information concerning the following aspects of health and health care through the study of the citizens of Seoul : 1. The measurement of health needs. 2. The extent of unmet need for medical attention. 3. The cost of medical care. 4. The attitudes of the folks towards illness, doctors and other healers, and health facilities available. 5. An analysis of socio-economic and cultural anthropologic factors. The source of information for this study consists of a two-stage systamatic sample, namely, 933 households consisting of 5,159 persons, a representative cross-section which is about one three-hundredth of all households (281, 601) and of the total population of Seoul (1,574,868) as of September 1, 1955. For the first stage, the sampling unit was the "Pan", which is the smallest cluster of households, and the sampling rate was 1/100 ; and for the second stage, the sampling unit was the household, and the rate was 1/3. In this sample, the loss rate was only 0.5%, which is extremely lower than that in other countries. Also, we were able to see a relatively constant sampling ratio between the various characteristic variables, too. Therefore, the data obtained from this sample can be assumed to represent the native population reasonably well. In order to exclude every possible bias, well-trained non-medical senior women college students were used as the interviewers. The form used consisted of the open-end questionaire, which was revised after a pilot study. For the determination of health needsm, the method of symptom-approach using 40 kinds of symptoms was used. The questionaire asked about the experiences during the preceding 6 months. As the survey was carried out during the one-month period from August 1, 1956, the data obtained from this study are the experiences of Seoul citizens from February 1 to July 31, 1956 ; 86.3% of those questioned were female heads of housholds. The findings of the survey are as follows : 1. It was found that 63.6% of Seoul citizens had no symptoms ; 36.4% of Seoul citizens had one or more symptoms during the 6-month period, averaging 1.9 symptoms during the half-year. Therefore, the morbidity incidence rate was 74 symptoms per 100 citizens. The most prevalent symptoms were related to diseases of the digestive system, nutritional, and parasitic infection. The frequency rate of this particular disease group of digestive system is much higher than that obtained in the study of hospital cases. The morbidity rate of females was more than two times that of males in the age groups of 15-44. In the male, the morbidity incidence was lowest in the age groups of 15-24 and highest in the age group of 65 and over ; however, in the female, the incidence was lowest in the age group of 5-14, and highest in the 45-64 age group. There were significant differences in the morbidity rate among the different socioeconomic family groups, those low in income and in educational standards having a higher rate ; the more overcrowded the living accommodation, the higher was the rate. Farmer, unemployed, and daily worker groups had higher morbidity rate than other occupational groups. 2. Only 42.8% of their symptoms did Seoul citizen regard as being and illness, and for 57.2% of their symptoms, medical care was not sought. Particularly, where repeated or frequent bleeding gums, poor vision, unexplained loss of weight, repeated nose bleeds, continued loss of appetite, unexplained tiredness (reqularly), persistant cons pation, persistant pains in the joints were the eminent symptoms ; more than 70% of these were not regarded by the people as abnormal conditions demanding medical care. This shows that increasing the number of medical personnel or the facilities for medical care will do little to improve the general health and the medical care of the people unless there is adequate health education for the people. If we make a similar survey at the rural level and compare the results with this data, we can easily confirm the assumption that the demand rate for medical care in rural communities will be much lower than that in Seoul, though the people in rural areas might have higher morbidity rates than that in Seoul. 3. The loss of work or other regular activity due to illness during the period of 6 months was 138 days per 100 persons, which was incurred by the 5.4% of entire citizen it was 124 days per 100 males and 152 days per 100 females. Among the various age groups, the lowest rate was in the 5-14 age group for both sexes, and the highest rate was in the 45-64 age group for males and in the over 65 age group for females. 4. Only 44% of the demand for medical care was met ; 15% of the demand was unmet, while the rest (41%) is uncertain. Consequently, it could be said that only one fifth of health needs was cared by medical personnel and related facilities. (Whole symptoms × 42.8/100 × 44.2/100 = 18.0). Among those whose symptoms were not cared for, 78% claimed economic difficulty as their reason, such as "no money" or "too expensive". This shows that the second inportant things to do for the inprovement of health and medical care is to provide some provision for the payment of the cost of medical care, so that every patient can get what he or she at any time and without delay or postponement. This might well be done by reorganizing existing medical personnel, facilities, and medical care expenses. 5. The total cost of medical care during the 6 months was HW 10,700 per family (including no-patient families), and HW 2,000 per person. Twice this cost of medical care is 7.2% of the average annual family income (HW 300,000) of Seoul City. In general, many factors, such as low income, high morbidity in the community, a higher demand for medical care account for the high ratio of medical cost to income. Therefore, it is presumed that in our rural communities, the cost of medical care would surpass 7.2% of the average annual family income. Only 1/1,000 of citizen incurred as much as a half of entire medical costs, and 1/40 of citizen incurred 87% of total charges while upon 39/40 of citizen fell 13% of the total charges. Low income families spent a greater proportion of their incomes on the costs of sickness than did the well-to-do and the wealthy. The mean costs and the median cists per illness paid to medical doctors was HW10,300 and HW1,500 respectively, while that paid to herb doctors was HW16,100 and HW1,700 respectively. The high mean cost of HW23,400 paid to hospitals, while its median is only HW1,000, is due presumably to serious cases coming to the hospital. But it is rather ridiculous that mean costs paid to specialists should be less than half that paid to general practitioners. It is also surprising that they paid a mean of HW9,800 and a median of HW2,500 for moxa and acupuncture compared with a mean of HW9,400 and a median of HW1,500 for general practitioner. These phenomena show that there is much waste in the medical expenditures of the people. The analysis of medical costs according to payment to doctors, hospitals, and for drugs, etc.,was rather difficult to make since the current accounting system in this country does clearly differentiate these categories. 6. The responses given to interviewers regarding what was believed to be the cause of whether due to demos, curse, witchcraft, sin, and fear or fright, were frank and revealing ; in general, those questioned born in the southern provinces of Korea gave more superstitious answers than those born in the northern provinces of Korea. Among the different religious groups, Christians gave the least superstitious answers. 7. Regarding the choice of healer, 83.4 of those questioned preferred medical doctors ; of these 71.9% were in general practice, 5.9% were specialists, 0.9% were foreign doctors, 4.7% denoted hospitals. Only 12.7% preferred herb-doctors ; the rest chose other healers or patent drugs. However, only 71.5% of them actually visited medical doctors and as many as 14.5^ of them visited herb-doctors, and the number visited drugstore or superstitious healer increased to two and a half times of the number they wanted, Such a phenomenon might be interpreted as due to the belief that herb-doctors charge less than medical doctors in general. But actual figures reveal the opposite, for 73.0%, 22.3%, and 4.7% of the cost paid to healers were to medical doctors, herb-doctors, and other healers respectively. Facts already mentioned reveal that herb-doctors charge more per illness than medical doctors on an average. The higher the educational level of the head of the household, whether male or female, the stronger the choice for medical doctors. Administrative warkers, specialistic and technical workers, and sales business groups had stronger choice for medical doctors than the other occupational groups, christian families had stronger choice for medical doctors than the other religious groups. 8. Inquiring what kind of treatment were given at the clinic of various healers visited, it is surprising to find that consultation, injections, dressings, prescription and even operation were frequently done at drugstores, and injections by herb-doctor. Mean duration and median duration of care given per illness was 13.1 days and 2.9 days respectively in general ; however that of cared by herb-doctors were the longest being 17.0 days and 4.4 days. About a half of patients had treatment lasting three days or less and 14% of patients spent one month or longer for the care of their illness. 9. Very few seems to have their own family doctor. The most prevalent reason for their choosing healer is nearness and convineance, and hearing good rumour. More than 30% of the patients changed their doctor or healer during treatment. The primary reason given for their change of healar was the "effectiveness of the treatment." ; other reasons such as "expensive charge", "unkindness" or "recommendation by family doctor" had little role in causing them to change healers. The only one exception was seen in the case of one hospital where the complaint of unkindness was decisive. Random advertisement of healers and drugs, and free also of any drugs without doctor's prescription should be controled ; and the competition for patients between general hospitals and general practitioner should be abolished. 10. Relatively few interviewees could indicate why they like or dislike a doctor or herb-medicine was preferable for such vague conditions as "cold", "women's disease", "Internal disease", "General malaise", etc. About 59% of the interviewees commented favorably on "tonics" ; and actually, more than 5% of sampled familieg used "tonics" costing an average HW15,400 during the period, which is 7.7% of entire annual expenditures from medical care. The family groups higher in income used "tonics" more frequently than the lower income groups. 11. Only 54.4% of interviewees recognized distinction between a general hospital and a doctor's clinic. Those living in Songpuk-Ku, and Chung-Ku knew this distinction, whereas those living in Yong-wan-Ku and Yondongpo-Ku had a relatively poor understanding of a general hospital . The higher the educational standard of the interviewees, the better their understanding of the general hospitals were "excellent medical doctors", "good facilities", "cheap cost", and "clean". On the other hand, the main unfavorable comments were "unkindness", and "keeps us waiting". Only 22.4% of respondents ever heard the word "health center". Most people generally had poor understanding about the location, function, financing and administration of health centers. The higher the educational standard of the female heads of households, the better their knowledge about health centers. Only 5.7% of responding families ever visited to health center ; the higher in income and in educational standards, the higher was the rate. 12. Regarding medical insurance, 45.5% of interviewees gave favorable opinions, while 24.2% had no opinions and 30.3% had adverse opinions. Regarding a national health service, 40.9% responded favorably, 26.9% were indifferent, and 32.2% responded adversely. The group lowest in educational standards and in income had favorable respond to a national health service system.restrictio

Multifunctional Single-Pole Single-Though pulse modulation switch circuit and driving method Thereof

본 발명은 레이더에 사용되는 다기능 펄스 변조기(Multi-purpose Pulse Former)에 관한 것으로서, 초광대역 레이더(UWB Radar)나 협대역 펄스 레이더(Pulsed Radar)에 필수적인 펄스 변조기능, OFF 상태에서 송신 누설신호 제거기능(TX Leakage cancellation), 펄스 압축(Pulse compression)을 위한 위상 변조기능을 포함하고, 주파수천이 변조 레이더(FSK Radar), 주파수 변조 연속파 레이더(FMCW Radar), interrupted FMCW, pulsed-FMCW, 도플러(Doppler), pulse-도플러 등을 포함하는 여러 형태의 CW 레이더 장치에 적합한 차동 증폭기로 동작이 가능한 다기능 SPST(Single-Pole Single-Though) 펄스변조 스위치 회로에 관해 개시한다. 본 발명은 믹서(Mixer)나 위상변조기로 흔히 사용되는 길버트 셀(Gilber Cell)의 동작 및 구동 원리를 달리하여, 누설전류 혹은 누설신호를 최소화한 펄스 레이더 및 CW 레이더 장치에 적합한 다기능 SPST(Single-Pole Single-Though) 펄스변조 스위치 회로에 관한 것이다. 본 발명에 따르면, 초광대역 혹은 협대역 펄스 신호 발생을 위한 펄스 변조가 가능하고, 연속된 펄스 신호 사이의 누설신호의 제거를 통해 수신단의 신호 대 잡음비(Signal to Noise ratio, SNR)를 향상시킬 수 있다. 또한, 위상 변조 기능이 탑재되어 있기 때문에 추가적인 회로 없이 레이더 장치에서의 펄스 압축기법(Pulse Compression Technique)을 이용한 SNR 향상이 가능하다. 더욱이 이득을 갖는 차동 증폭기로의 동작이 가능하기에 도플러, FMCW, 그리고 FSK 등과 같은 CW 기반의 레이더 장치 혹은, 주파수와 위상 변조를 기반으로 하는 통신 장치에서도 사용이 가능하다

K-밴드 FMCW/UWB 이중-모드 레이더 송신기 CMOS 집적회로

학위논문(박사) - 한국과학기술원 : 전기및전자공학과, 2012.8 ,[v, 87 p. :]Due to rapidly growing of radar sensor market such as object range detection sensors, collision-avoid sensors, speed-detection sensors, traffic-control sensors, health-care sensors, and human motion detection sensors, microwave and millimeter-wave radars have paid much attention. For these applications, high per-formance, small size, and low cost are crucial for the radars. Especially, in automotive safety applications, radar sensor is the key component to improve the convenience and the safety of the automobile. Compared with other range sensor such as ultrasonic and vision sensor, the radar sensor has the benefit in terms of ro-bustness against the unexpected circumstances such as fog, rain, and light. However, the cost inefficiency is the bottleneck of the radar sensor in automotive sensors. Furthermore, at least 6 to 10 short range and medium range radars are required to provide the $360^\circ$ safety with 0.1meter and 1meter resolution respectively. These features restrict the penetration of radar sensors in the automobile. Thus, development of cost effective radar sensor are urgent. In K-band, frequency allocation for UWB radar is at least more than several GHz with extremely low output power constraint. The range resolution is directly determined by the bandwidth, thus the K-band UWB operation has the advantage in terms of range resolution at the short range. On the other hand, the bandwidth of FMCW radar allocated in K-band is excessively narrow. However, in terms of the transmit power and nar-row band nature, its maximum detectable range is 2~3 times longer than that of the UWB radar. Thus, this thesis proposes K-band dual-mode radar including FMCW and UWB mode and the main contribution is to implement the K-band Radar transmitter suitable for dual-mode radar and to propose the key sub-circuits appropriate for dual-mode radar. The proposed radar concept has the benefits of both mode of radar, which suggests the possibility of short range detection capability with high range resolution and of medium range detection capability with moderate range resolution. Also, to improve the performance of both operation modes, the pulse compression technique using binary phase modulation schemes in the UWB mode and the closed loop linearization technique using Phase-locked loop in the FMCW mode is implemented. The proposed dual mode radar transmitter is composed of RF front-end integrated in a single chip and external PLL using commercial product. The RF front-end is composed of the 24/26GHz dual band VCO using high Q asymmetric transformer, wideband frequency divider chain including dual band differential injection locking frequency divider, pulse former and wideband output balun stage. For 0.1meter range resolution, we propose and demonstrate the pulse former adopting the current steering for fast switching capability. The proposed pulse former operates as a switch to generate a pulse modulated carrier signal and a bi-phase modulator for pulse compression. The TX leakage is cancelled by pulse former’s own nature, ideally perfect leakage cancellation. The pulse former also operates as a differential gain amplifier for FMCW mode. The dual-mode radar transmitter is fully integrated on a single chip using TSMC 0.13- $\mu m$ 1-poly 8-metal CMOS process, which provides a 3.35 um-thick Cu top metal layer. The maximum bandwidth of the output spectrum is more than 4 GHz in pulse compression mode, thus the expected range resolution is more than 0.075 meter. The operation frequency of the dual mode transmitter tunes from 23.885 GHz to 24.724 GHz for low band and 25.758 GHz to 26.801 GHz for high band which covers 24/26 GHz UWB band and 24 GHz FMCW band. The FMCW mode signal using external PLL is modulated linearly using Triangular wave-form and the absolute error is below 1.5MHz. The -5dBm output peak power is measured in the condition of wire bonding with 108mW power consumption. Finally, the leakage power as low as -59dBm is achieved. The proposed dual-mode radar concept is demonstrated using dual-mode receiver which is integrated in a single chip with the transmitter. For FMCW mode, 42meter of maximum detection range and 0.6meter of range resolution are measured. In UWB mode, the demonstration is performed using a delay line based meas-urement. The DC power consumption of the dual-mode radar transceiver is 262mW.한국과학기술원 :전기및전자공학과

Design of a 24-GHz low-power CMOS voltage-controlled oscillator for radar sensor systems

학위논문(석사) - 한국과학기술원 : 전기및전자공학전공, 2007. 8, [ iv, 69 p. ]최근, 밀리미터 대역의 통신 시스템과 Radar 시스템에 관련된 연구가 활발히 이루어지고 있다. 이는 집적화, 소형화, high data-rates 그리고 넓은 통신 주파수 대역(large bandwidth)등 시스템의 질적 향상 요구가 증가하고 기존의 주파수 자원이 포화되고 있기 때문이다. 또한 군용으로 사용되던 거리, 속도 측정용 Radar를 일반 산업에서 응용하기 위해 초소형화를 시도하면서 초고주파 대역 Radar시스템 개발 및 연구가 이루어지고 있는 것도 그 원인이다. 특히 17GHz, 24GHz, 60GHz, 77GHz 등 Industrial, Scientific and Medical 분야에서 사용할 수 있도록 허가된 ISM band가 지정되면서 밀리미터 대역에서 동작하는 통신 시스템과 레이더 시스템에 관련된 연구가 증가하고 있다. 이러한 초고주파 대역의 시스템들의 RF front-end는 주파수 특성이 우수한 HBT, HEMT와 같은 화합물 반도체를 사용하여 제작되었지만 대량 생산 및 원가 절감을 위해 CMOS 공정을 이용하여 제작하려는 시도가 늘어나고 있다. 하지만, 아직까지 충분한 연구와 성과들이 보고되지 못했다. 통신 및 레이다 시스템의 성능에 지대한 영향을 끼치게 되는 주파수 생성기에 관련된 연구 역시 아직까지 큰 성과를 보고 있지 못하다. 주파수 생성기는 동작 주파수가 올라갈수록 그 성능이 매우 저하된다. 더욱이 CMOS공정을 사용하면 주파수 특성이 화합물 소자에 비해 떨어지기 때문에 이를 보완하기 위한 연구가 필요하다. 따라서 본 논문에서는 주파수가 증가하여 생기는 문제점들을 해결할 수 있고 저전압, 저전력 동작이 가능하고 밀리미터 대역 동작에 적합한 전송선 변압기를 이용한 전압 제어 발진기를 제안하고 설계하였으며, 성공적인 실험 결과를 얻었다. 일반적인 전압 제어 발진기 구조는 밀리미터 대역에서 동작하기 위해 전원 전압과 전류의 증가가 불가피하며, 따라서 개선된 위상 잡음 특성을 위해 소모 전력의 증가라는 문제점이 생긴다. 변압기-정귀환(Transformer-Feedback) 전압 제어 발진기 구조를 사용하면 소모 전력의 증가를 최소화할 수 있다. 이 구조에 사용되는 나선형 변압기는 주파수가 증가할수록 구조적 특성상 Q factor가 현격히 떨어지고 발진기의 성능을 저하시킨다. 따라서 본 논문에서는 초고주파 대역의 변압기-정귀환(Transformer-Feedback) 전압 제어 발진기 구조에서 나선형 변압기를 사용할 때 생길 수 있는 문제를 해결하기 위한 전송선 변압기를 이용한 구조를 제안하였다. 이 구조를 통해 소모 전력과 위상 잡음 특성을 향상시킬 수 있다. 제안된 전압 제어 발진기는 TSMC 0.18-m CMOS 공정을 이용하여 제작하였다. 제작된 전압 제어 발진기는 0.7V의 공급 전압에서 동작하며 8.4mW의 낮은 전력을 소모한다. 동작 주파수는 24.04GHz에서 24.54GHz로 조율됨을 확인하였고 출력 신호의 위상 잡음은 1MHz에서 -100dBc/Hz로 측정되었다. 이는 -177dBc/Hz의 FOM으로 동일 주파수에서 동작하는 전압 제어 발진기 중에서 매우 작은 전력으로 원활한 성능을 보임을 알 수 있다. 반면 제안된 회로는 제어 전압의 변화에 따라 주파수 조율 범위가 매우 한정되는 단점을 갖는다. 이는 초고주파 대역 발진기들의 공통된 문제이며, 따라서 이를 해결하기 위한 방안과 연구가 계속적으로 필요할 것이다.한국과학기술원 : 전기및전자공학전공