• 보건행정학회지
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• 제6권2호
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• pp.58-90
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• 1996

This study provides an empirical analysis of location competition for demand maximization by central place theory among physicians in nonmetropolitan areas of Korea. The results show that the primary care physicians distribute themselves evenly from urban communities to rural communities. The subspecialists, however, cluster together in major cities rather than decentralize themselves in rural counties. This study establishes the three statistical models : Primary care physicians, subspecialist physicians, and total physicians. Two models of primary care physicians and total physicians have a strong significance in multiple regression analysis (p=-.0001). The primary care model explains approximately 45% of the variation and the total physicians model explains approximately 70% of the variation in physician/1,000 population ratios across national counties. The subspecialist physicians model analysze the tobit regreassion because of the left consored and truncated values(57 cases = 0). In all three models, analysis of the coefficiencts for physician centralization degrees in the 0- to 5- and 5- to 10-km rings around the core county reveals each a positive and negative association betwee these degrees and the physician/1,000 population ratios in the core county. Also, the results provide moderate evidence that the relationship between clinic physicians and community hospitals is competitive, and the relationship between clinic physicians and pharmaceutists is synergistic. This suggests that public policy makers and local self-governing bodies must take an active role to ensure procider availability and the regional health planning in all nonmetropolitan areas of Korea.

• Anatomy and Cell Biology
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• 제51권4호
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• pp.243-250
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• 2018

Because of its embryonic origin, the thyroid gland is predisposed to multiple anatomical variations and developmental anomalies. These include the pyramidal lobe, the origin of levator glandular thyroidae, the absence of the isthmus, ectopic thyroid, accessory thyroid tissues, etc. These anatomical variations are clinically significant to surgeons, anatomists, and researchers. The present study was designed to report anatomical variations and developmental anomalies of the thyroid gland in Ethiopian population. The study was conducted on 40 cadavers used for routine dissection classes. The thyroid gland was exposed and observed for any variations and developmental anomalies. The length, width, and thickness of the lobes were measured using a vernier caliper. Differences in the incidence of pyramidal lobe and absence of the isthmus between sexes were tested using a Pearson chi-square test. The mean length, width, and thickness of the right lobe were 4.24 cm, 1.8 cm, and 1.6 cm, respectively, whereas it was 4.08 cm, 1.8 cm, and 1.6 cm, respectively for that of the left lobe. The pyramidal lobe was noted in 52.5% of the cadavers. The levator glandulae thyroidae were prevalent in 40% of the cadavers. The isthmus mainly overlies the 2nd to 4th tracheal rings and was absent in 7.5% of the cadavers. Accessory thyroid tissue and double pyramidal lobes were noted in 2.5% of the cadavers. Most of the variations of the thyroid gland were seen frequently in female but it was not statically significant. Different clinically important and rare variations of the thyroid gland were found.

• Advances in nano research
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• 제10권2호
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• pp.129-138
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• 2021

In present article, utilizing the Love shell theory with volume fraction laws for the cylindrical shells vibrations provides a governing equation for the distribution of material composition of material. Isotopic materials are the constituents of these rings. The position of a ring support has been taken along the radial direction. The Rayleigh-Ritz method with three different fraction laws gives birth to the shell frequency equation. Moreover, the effect of height- and length-to-radius ratio and angular speed is investigated. The results are depicted for circumferential wave number, length- and height-radius ratios with three laws. It is found that the backward and forward frequencies of exponential fraction law are sandwich between polynomial and trigonometric laws. It is examined that the backward and forward frequencies increase and decrease on increasing the ratio of height- and length-to-radius ratio. As the position of ring is enhanced for clamped simply supported and simply supported-simply supported boundary conditions, the frequencies go up. At mid-point, all the frequencies are higher and after that the frequencies decreases. The frequencies are same at initial and final stage and rust itself a bell shape. The shell is stabilized by ring supports to increase the stiffness and strength. Comparison is made for non-rotating and rotating cylindrical shell for the efficiency of the model. The results generated by computer software MATLAB.

• Asian Journal of Atmospheric Environment
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• 제8권1호
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• pp.35-47
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• 2014

The purpose of the study is to evaluate the pollution level (gaseous and particle phase) in the public facilities for the PAHs, non-regulated materials, forecast the risk level by the health risk assessment (HRA) and propose the guideline level. PAH assessments through sampling of particulate matter of diameter < 2.5 ${\mu}m$ ($PM_{2.5}$). The user and worker exposure scenario for the PAHs consists of 24-hour exposure scenario (WIES) assuming the worst case and the normal exposure scenario (MIES) based on the survey. This study investigated 20 PAH substances selected out of 32 substances known to be carcinogenic or potentially carcinogenic. The risk assessment applies major toxic equivalency factor (TEF) proposed from existing studies and estaimates individual Excess Cancer Risk (ECR). The study assesses the fine dusts ($PM_{2.5}$) and the exposure levels of the gaseous and particle PAH materials for 6 spots in each 8 facility, e.g. underground subway stations, child-care facilities, elderly care facilities, super market, indoor parking lot, terminal waiting room, internet caf$\acute{e}$ (PC-rooms), movie theater. For internet caf$\acute{e}$ (PC-rooms) in particular, that marks the highest $PM_{2.5}$ concentration and the average concentration of 10 spots (2 spots for each cafe) is 73.3 ${\mu}g/m^3$ (range: 6.8-185.2 ${\mu}g/m^3$). The high level of $PM_{2.5}$ seen in internet cafes was likely due to indoor smoking in most cases. For the gaseous PAHs, the detection frequency for 4-5 rings shows high and the elements with 6 rings shows low frequency. For the particle PAHs, the detection frequency for 2-3 rings shows low and the elements with 6 rings show high frequency. As a result, it is investigated that the most important PAHs are the naphthalene, acenaphthene and phenanthrene from the study of Kim et al. (2013) and this annual study. The health risk assessment demonstrates that each facility shows the level of $10^{-6}-10^{-4}$. Considering standards and local source of pollution levels, it is judged that the management standard of the benzo (a)pyrene, one of the PAHs, shall be managed with the range of 0.5-1.2 $ng/m^3$. Smoking and ventilation were considered as the most important PAHs exposure associated with public facility $PM_{2.5}$. This study only estimated for inhalation health risk of PAHs and focused on the associated cancer risk, while multiple measurements would be necessary for public health and policy.

• 전자공학회논문지
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• 제50권1호
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• pp.174-179
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• 2013

이 논문에서는 multiple split ring resonator(MSRRs)와 로딩된 스위치드 제어부를 이용하여 2개의 전송영점을 가지는 대역통과 여파기를 설계하였다. 높은 선택도와 칩 사이즈의 초소형화를 위해 비대칭의 급전 선로를 도입하여 통과 대역 주위에 위치한 전송 영점 쌍을 생성하였다. Cross coupling 또는 source-load coupling 방식을 이용한 기존의 여파기와 비교해보면 이 논문에서 제안된 여파기는 단지 2개의 공진기만으로 전송 영점을 생성하여 높은 선택도를 얻었다. 여파기의 선택도와 민감도(삽입 손실)를 최적화하기 위해 비대칭 급전 선로의 위치에 따른 전송 영점과 삽입손실의 관계를 분석하였다. 통과 대역 주파수의 가변과 30dBm 정도의 고 출력 신호를 처리하기 위해 MSRRs의 최 외각 링에 MIM 커패시터와 stacked-FET으로 구성된 SOI-CMOS 스위치드 제어부가 로딩되어 있다. 스위칭 트랜지스터의 전원을 켜고 끔으로써 통과 대역 주파수를 4GHz로부터 5GHz까지 이동시킬 수 있다. 제안된 칩 여파기는 0.18-${\mu}m$ SOI CMOS 기술을 이용함으로써 높은 Q를 가지는 수동 소자와 stacked-FET의 집적을 가능하게 만들었다. 설계된 여파기는 $4mm{\times}2mm$ ($0.177{\lambda}g{\times}0.088{\lambda}g$)의 초소형화 된 크기를 가진다. 여기서 ${\lambda}g$는 중심 주파수에서의 $50{\Omega}$ 마이크로스트립 선로의 관내 파장을 나타낸다. 측정된 삽입손실(S21)은 5.4GHz, 4.5GHz에서 각 각 5.1dB, 6.9dB를 나타내었다. 설계된 여파기는 중심 주파수로부터 500MHz의 오프셋에서 20dB이상의 대역외 저지 특성을 나타내었다.

• 식물병연구
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• 제16권3호
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• pp.232-237
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• 2010

Tomato spotted wilt virus(TSWV)의 상습 발생지인 안양지역에서 가지, 알타리무, 슈가로프에서 TSWV가 발생하였다. 알타리무에서는 잎에 괴저반점과 뿌리에 괴저 병징이 나타났다. 가지에서는 잎에 전형적인 다중 원형반점을 나타냈으며 열매에 심한 괴저를 나타냈다. 슈가로프에서는 잎에 전형적인 원형반점과 심한 위축 병징이 나타났다. 가지, 알타리 무, 슈가로프에서 분리한 TSWV의 생물적 특성은 흰 명아주, 붉은 명아주, 담배(N. devney)에서는 국부 감염이었으며, 담배(N. glutinosa, N. benthamiana)와 독말풀(D. stramonium)에서는 전심감염이었다. 가지와 슈가로프에서 분리한 TSWV는 병원성이 유사하였으나, 알타리 무에서 분리한 TSWV는 N. tabacum 'Xanthi NC' 등 5종의 담배에서 국부 감염되어 병원성이 매우 상이하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제22권1호
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• pp.5-11
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• 1999

This paper reviews recent major activities on instrumentation and methodology of PET. The performance of the PET instrumentation can be expressed by four physical characteristics, 1) spatial resolution, 2) coincidence resolving time, 3) energy resolution, and 4) detection efficiency. The physical and technical aspects of PET systems are briefly discussed along with these characteristics. Toward high resolution PET the recent trend has been to design multiple rings of densely packed detector arrays with scintillators. In order to satisfy the sampling requirement in reconstruction, continuous detector units has been developed. Iterative image reconstruction algorithms have received considerable attention for improvement of both the sampling requirement and image quality toward the stationary PET. Better resolving time improves the maximum true coincidence rate, which is also increased with more detectors placed in coincidence with each other. It suggests that volume PET is promising for enhancement of detection efficiency. The scattered coincidence event rate may be reduced by using detectors with better energy resolution. The use of interplane septa, however, takes over improvement of energy resolution in 2D PET. Energy resolution becomes an important factor for image quality under the condition of septa removal such as volume PET. Toward full utilization of emitting photons, 3D reconstruction incorporating oblique rays has been studied, and volume reconstruction algorithms have been developed. Practical volume PET systems impose heavy burden not only to detector sets and coincidence circuits, but also to computers in the memory requirements and the data processing. In conclusion, there have been many ingenious methods in development of PET instrumentation, which are based on unique capability of PET. They will be expected to overcome technical limitations, and to approach the fundamental limits.

• 한국전기전자재료학회논문지
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• 제26권4호
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• pp.271-274
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• 2013

Power Metal Oxide Semiconductor Field Effect Transistor's (MOSFETs) are well known for superior switching speed, and they require very little gate drive power because of the insulated gate. In these respects, power MOSFETs approach the characteristics of an "ideal switch". The main drawback is on-resistance RDS(on) and its strong positive temperature coefficient. While this process has been driven by market place competition with operating parameters determined by products, manufacturing technology innovations that have not necessarily followed such a consistent path have enabled it. This treatise briefly examines metal oxide semiconductor (MOS) device characteristics and elucidates important future issues which semiconductor technologists face as they attempt to continue the rate of progress to the identified terminus of the technology shrink path in about 2020. We could find at the electrical property as variation p base dose. Ultimately, its ON state voltage drop was enhanced also shrink chip size. To obtain an optimized parameter and design, we have simulated over 500 V Field ring using 8 Field rings. Field ring width was $3{\mu}m$ and P base dose was $1e15cm^2$. Also the numerical multiple $2.52cm^2$ was obtained which indicates the doping limit of the original device. We have simulated diffusion condition was split from $1,150^{\circ}C$ to $1,200^{\circ}C$. And then $1,150^{\circ}C$ diffusion time was best condition for break down voltage.

• 한국임상수의학회지
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• 제37권2호
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• pp.106-108
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• 2020

An eight-month-old, outdoor, intact male English Pointer dog weighing 23.5 kg presented to the hospital with signs of hematochezia, soft stools, and weight-loss. There were no remarkable findings on physical examination, complete blood count, serum biochemistry, electrolyte and gas analysis, and radiography. The serologic and Polymerase Chain Reaction (PCR) tests for canine parvovirus were negative. A fecal smear examination showed rod-shaped, sporeforming bacteria. Additionally, a fecal flotation test showed ova of Ancylostoma spp. The size of ova was 60 × 40 ㎛, and it was identified as Ancylostoma caninum using light microscopy. The PCR test indicated a Clostridial perfringens infection and the presence of C. perfringens alpha toxin. The diagnosis given was C. perfringens enterotoxicosis with ancylostomiasis. Treatment included antibiotics (metronidazole, trimethoprim-sulfamethoxazole) and anthelmintics (afoxolaner, milbemycin oxime). After two weeks, the clostridial infection resolved, but ancylostomiasis persisted for six weeks. The anthelmintic was changed to Drontal^â plus (praziquantel/pyrantel pamoate/febantel). After four weeks, there were no remarkable findings in the fecal samples, but the patient still presented with watery stools and hematochezia. Survey of abdominal ultrasound had performed, and a target-like sign with multiple rings was seen in the cecocolic region. The patient was diagnosed with A. caninum-induced cecocolic intussusception from the history and clinical signs. After a surgery, he recovered fully. This is the first clinical case report of Ancylostoma caninum parasitizing from the small intestine and causing an intussusception in the large intestine.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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• pp.25-29
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• 2004

Corona on polymer materials causes deterioration by the combined action of the discharge striking the surface and the action of certain chemical compounds that are formed by the discharges. In the design and manufacture of polymer insulators must be sufficiently large to avoid corona discharges, otherwise a shielding or corona ring (grading ring) needs to be installed on the insulator. To conduct this purpose, many researchers have investigated end-fitting of polymer insulator by voltage distribution simulation and electrical test. Grading rings are used to improve the performance of the insulator in multiple ways. They can reduce corona and associated audible noise and radio influence and television interference. The factors determining the uses of a grading ring are line voltage, geometry and dimensions of end fittings, geometry and dimensions of line hardware, and environmental conditions. In this paper, electrical property of polymer insulator with end-fitting design have been investigated by electrical field analysis, various end-fitting design, tracking wheel test, corona inception voltage and extinction voltage. Electrical field analysis is conducted by FEM program and various end-fitting is designed through this result. Designed end-fittings are manufactured and their performance is conducted by electrical performance test.