• Journal of Radiation Protection and Research
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• v.34 no.1
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• pp.31-36
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• 2009

The purpose of this study is to measure the tube voltage, the tube current/volume, exposure time and exposure dose of diagnostic X-ray unit in each doctor offices, hospitals and general hospitals for evaluating the performance of such device, to learn the method and technology of its measurement and to suggest its importance. Research subjects were total 30 X-ray units and divided into groups of 10 X-ray units each. The tube voltage, the tube current/volume, exposure time and exposure dose were measured using percentage average error, and then reproducibility of exposure dose was measured through calculating coefficient of variation. The results are like followings; The tube voltage correctness examination showed that incongruent devices among total 30 X-ray units were 5 devices (16.7%). The tube current correctness examination showed that incongruent X-ray units were 3 devices (10.0%). The tube current volume correctness examination showed that incongruent X-ray units were 4 devices (13.3%). Finally, according to exposure time correctness examination, incongruent X-ray units were 5 devices (16.7%) and according to reproducibility examination of exposure dose, incongruent X-ray units were 7 devices (23.3%). Above results showed serious problem in performance management based on management regulation of diagnostic X-ray unit; it means that regular checkout and safety management are required, and as doing so, patients will be able to receive good quality of medical service by the reduction of radiation exposure time, image quality administration, unnecessary retake and etc. Therefore, this study suggests that the performance of diagnostic X-ray units should be checked regularly.

• The Korean Journal of Cytopathology
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• v.9 no.1
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• pp.37-44
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• 1998

OBJECTIVE: False negatives of cervical smears due to screening errors pose a significant and persistent problem. AutoPap 300 QC System, an automated screening device, is designed to rescreen conventionally prepared Pap smears initially screened by cytotechnologists as normal. Clinical experience and sensitivity of the AutoPap 300 QC System were assessed and compared with current 10% random qualify control technique. MATERIALS AND METHODS: In clinical practice, a total of 18,592 "within normal limits" or "benign cellular changes" cases classified by The Bethesda System were rescreened by the Autopap System. In study for sensitivity of The AutoPap System to detect false negatives, a total of 1,680 "within normal limits" or "benign cellular changes" cases were rescreened both manually and by the AutoPap System. The sensitivity of the AutoPap System to these false negatives was assessed at 10% review rate to compare 10% random manual rescreen. RESULTS: In clinical practice, 38 false negatives were identified by the AutoPap System and we had achieved 0.2% reduction in the false negative rate of screening error. In study for sensitivity, 37 false negatives were identified by manual rescreening, and 23 cases(62.2%) of the abnormal squamous cytology were detected by the AutoPap System at 10% review rate. CONCLUSONS: The AutoPap 300 QC System is a sensitive automated rescreening device that can detect potential false negatives prior to reporting and can reduce false negative rates in the laboratory. The device is confirmed to be about eight times superior to the 10% random rescreen in detecting false negatives.

• Journal of Pharmacopuncture
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• v.5 no.2
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• pp.120-136
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• 2002

Objectives : The purpose of this study is to investigate Acute and Subacute Toxicity, and Anti-cancer Effect of H Herbal-acupuncture on mice and rats. Methods : Balb/c mice were injected intraperitoneally with H Herbal-acupuncture for $LD_{50}$ and acute toxicity test. Sprague-Dawley rats were experimented in the same way for subacute toxicity test. H Herbal-acupuncture was injected into abdomen of mice having S-180 cancer cell line. Result : 1. During the test, $LD_{50}$ could not be counted since there was no expired subjects. 2. In an acute toxicity test, the loss of motility and reflex action was observed, but weight increased in the treatment group, compared with those in the normal group (P<0.05). 3. In an acute toxicity test of serum biochemical values of mice, glucose increased in the treatment group II while total cholesterol was increased in the all treatment groups (P<0.05). 4. In a subacute toxicity test, a little loss of motility and reflex action was observed in the treatment group. Weight of mice in the treatment group decreased on the 28th day. 5. In a subacute toxicity test, liver weight was decreased but lung weight of mice increased in the all treatment groups (P<0.05). 6. As a result of measuring Complete Blood Count test (CBC) of rat, HCT was decreased in treatments even though it was not significant, compared with the normal group (P<0.05). 7. In a serum biochemical value test of subacute toxicity, total protein and albumin decreased in the all treatment groups. Creatinine, glucose, GOT increased in the treatment group I compared with the control group. Alkaline phos-phatase decreased in treatment II group, compared with the control group (P<0.05). 8. Median survival time that was measured in the rats treated with sarcoma-180 cancer cell Median decreased in the treatment group, compared with the control group (P<0.05). 9. Natural killer cell activity showed significant reduction at 100:1 and 10:1 E/T ratio while it increased at 50:1 E/T ratio. It is inferred that there was an error in the experiment (P<0.05). 10. In an interleukin-2 productivity test, even though it decreased in lung cancer, and increased in abdomen cancer, but it was only a small difference (P<0.005). 11. After injecting B16F10 cell into a capillary vessel of C57BL/6 mice and generating metastasized lung cancer, the lung was examined with the naked eye. It was not possible to see metastasized cancer in the all groups on the seventh day but the cancer was viewed on the fourteenth day. The number and volume of metastasized cancer in the treatment group enlarged in the treatment group, compared with the control group. Conclusion : According to the results, H herbal-acupuncture took no effects in cancer.

• Journal of the Korean Society of Radiology
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• v.7 no.3
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• pp.251-257
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• 2013

Spatial dose rates of high dose $^{131}I$ therapy patients were Measured Three dimensional (X, Y, Z) distributions. I have constructed geometrical an aluminum support structure for spatial dose meters placed in 5 different heights, 8 different azimuthal angles, 6 different time interval and distance 100 cm from High dose$^{131}I$ therapy patients. when the height of vertical plane Spatial dose distribution is 100 cm, the Spatial dose rates is max and the error range is low. the vertical plane Spatial dose rates was found to be 71.85 ${\mu}Sv/h$ on the average at a distance of 100 cm, height 100 cm, from the patients 24 hours after $^{131}I$ oral administration. I divided 12 patients into two groups. I have analysed group A (drinking 5 L water) and group B (drinking 3 L water) in order to measure decrease spatial dose rates. I have found the spatial distributions of patient dose rates is $44.9{\pm}7.2$ ${\mu}Sv/h$ in group A and $100.3{\pm}8.1$ ${\mu}Sv/h$ in group B by 24 after $^{131}I$ oral administration. the reduction factor was found to be approximately 54 % through drinking 5 L water during 24 hours.

• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.411-421
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• 2012

The stagnant growth in 3D market due to 3D movie contents shortage is encouraging development of techniques for production cost reduction. Elimination of vertical disparity generated during image acquisition requires heaviest time and effort in the whole stereoscopic film-making process. This matter is directly related to competitiveness in the market and is being dealt with as a very important task. The removal of vertical disparity, i.e. image rectification has been treated for a long time in the photogrammetry field. While computer vision methods are focused on fast processing and automation, photogrammetry methods on accuracy and precision. However, photogrammetric approaches have not been tried for the 3D film-making. In this paper, proposed is a photogrammetry-based rectification algorithm that enable to eliminate the vertical disparity precisely by reconstruction of geometric relationship at the time of shooting. Evaluation of proposed algorithm was carried out by comparing the performance with two existing computer vision algorithms. The epipolar constraint satisfaction, epipolar line accuracy and vertical disparity of result images were tested. As a result, the proposed algorithm showed excellent performance than the other algorithms in term of accuracy and precision, and also revealed robustness about position error of tie-points.

• Progress in Medical Physics
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• v.6 no.2
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• pp.51-60
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• 1995

Lithium Fluoride (LiF; TLD-100) crystal chips are normally used as thermolu minescence dosimeters (abbreviated as NC-100) for estimating the absorbed dose to the skin of a patient or in a solid water phantom undergoing radiotherapy with megavoltage photon (6 and 15MV) beams. In general, investigation has revealed a reduction in the sensitivity of NC-100 chips after many runs through heating cycles. A TLD-100 chip laminated with gold plate (140${\mu}{\textrm}{m}$) on the upper surface layer of its face toward the photon beam (abbreviated as GC-100) has properties different from that of a NC-100 chip activated by incident photons and contaminant electrons with various lower energies coming from the gantry head and air. Activation of the valence band electrons of GC-100 chips by incident photons, positrons and electrons-which come from the gold plate by mainly pair production process and partly from Compton scattering-results in more enhanced signal intensity, higher response per monitor unit, as well as a good linearity with monitor units and independence of dose rate. Since the electron beams (6 and 15 MeV) do not have the probability of pair production process with gold plate, there is only a small difference (about a 3.3％ increase for 15 MeV) in the signal gaps in the TL readout for electron beams between GC- and NC-100 chips. The 3.3％ increase is entirely due to the buildup caused by the 140 m gold plate. The sensitivity of GC-100 chips is much more susceptible to high energy photon beams than electron one because of pair production. The interaction of high energy photon with a material of high atomic number, such as the good plate in this case, results in a considerably significant probability of pair production. The gold plate on the NC-100 chips acts as not only an intensifier of their signals but also acts as a filter of contaminant electrons in therapeutic high energy X-ray beams.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.25-28
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• 1982

Estimation of liver size is essential in the diagnosis of liver disease, Many approaches have been attempted in evaluation of liver size such as the measurement of length, area and volume. Among these, area and volume measurements are accurate but complicated, so we commonly use formerly introduced various linear measurements, but in scintigraphy one must calculate the actual liver size using rate of reduction, which is time consuming. Because of these reasons, we carried out present study to represent liver size by means of a simple liver measurement like we express the cardiac size by cardiothoracic ratio. Our cases consisted of 100 clinically normal subjects as the normal group and 50 patients suffering from liver disease and diagnosed to have hepatomegaly on abdominal palpation and scintigram at Dept, of Radiology of St. Mary's Hospital, Catholic Medical College during the period of 8 months from Jan. 1980. We measured the liver size using 4 linear diameters(Fig. 1). And as the reference measurement, the distance from the right margin of the liver to the left margin of the spleen was measured. We called this "abdominal transverse diameter(ATD)". The results were as follows; 1) The smallest value was recorded in the midline vertical diameter (MVD). It was $4.2{\pm}0.4cm$ in normal group and $5.0{\pm}0.6cm$ in the hepatomegaly group. 2) The diameter using other methods ranged from 5.6 to 7.2 cm in the normal group and from 6.3 to 7.5cm in the hepatomegaly group. 3) There was significant difference in the ratio of each diameter to ATD between the normal and hepatomegaly group (<0.01). We called this "hepato-abdominal ratio". 4) The "hepato-abdominal ratio" using MVD is $0.43{\pm}0.06$ in the normal group and $0.53{\pm}0.07$ in the hepatomegaly group. The "hepato-abdominal ratio" of MVD was most significantly different between normal and hepatomegaly group. 5) The tolerance limits(99%) of "hepato-abdominal ratio" using MVD is from 0.41 to 0.45 in the normal group and from 0.51 to 0.55 in the hepatomegaly group. Therefore, by reasons of error during measurement and convenience of memory, it was warranted to suggest hepatomegaly when "hepato-abdominal ratio" using MVD is more than 0.5 in the interpretation of hepatic scintigram.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.67-72
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• 1994

현재 가전제품의 개발방향은 고효율화, 다기능화와 더불어 환경문제를 고려하는 방향으로 진행되고 있다. 환경문제로는 여러가지가 거론되고 있는데 제품의 소음에 대한 문제도 이제는 성능의 관점에서와 더불어 환경의 문제로도 인식되어야 한다고 생각한다. 특히 고속의 팬종류가 사용되는 가전제품에 있어서 저소음 성능은 판매력에 직접영향을 미치는 중요 판매전략으로 대두되고 있는 상황이다. 진공청소기는 가전제품중에서 매우 시끄러운 제품중에 속한다. 그 이유는 모타가 분당 30,000회 이상의 고속회전을 하면서 축에 연결되어 잇는 임펠러를 회전시켜 공기를 흡입, 배출시키는 일련의 작동을 하면서 여러가지 진동 및 유체소음을 일으키기 때문이다. 팬모타에서 발생한 소음과 진동은 여러가지 복잡한 전달경로를 거쳐서 외부로 전달되어진다. 따라서 청소기의 전체적인 소음을 감소시키기 위한 대책으로는 크게 두가지 방법으로 나누어 생각해 볼 수 있는데, 그 첫번째가 주된 소음원인 팬모타의 소음특성을 개선하는 방법이고 다른 하나는 팬모타로부터 발생된 소음이 밖으로 전달되는 경로를 적절하게 차단하는 방법으로서 청소기 내부에서 여러가지 방법을 사용하여 소음을 저감시키는 방법이다. 본 연구에서는 첫번째 방법인 팬모타의 소음을 감소시키는 대책들에 대하여 중점적으로 기술하려고 한다. 그 이유는 청소기 내부의 구조개선을 통하여 소음을 저감시키는 방법은 그동안 많이 실시되어 실험결과들이 축적되어 있는 반면 그 방법의 실시에는 구조적인 문제점 등 한계가 있기 때문에 더욱 조용한 청소기를 개발하기 위하여는 주된 소음원인 팬모타의 소음을 낮추어야 할 필요가 절실하게 요구되고 있기 때문이다.래그(drag) 토크의 영향과 치타음 저감을 위한 개선된 클러치 특성을 제시하였다. 클러치는 동력을 전달 또는 차단하는 기능 뿐만 아니라 엔진이나 변속기에서 발생하는 소음이나 진동을 저감시키는 기능을 가지고 있다. 따라서 엔진 공회전시에 발생하는 치타음(rattle noise)이나 비틀림 진동을 저감시키는 방법으로는 여러가지가 있으나 클러치 디스크(clutch disc)의 비틀림 기구의 설계 인자들을 적절히 조절함으로써 변속기의 인풋기어에 전달되는 비틀림 진동을 저감시키는 방법이 일반적으로 수행되어지고 있다. 본 연구는 4 실린더 4 싸이클 1.5L 엔진을 장착한 경승용차의 실차실험을 통해 공회전시 엔진 플라이휘일과 인풋기어에서의 회전수 변동을 측정하고, 이 실험 데이타를 기초로 하여 엔진 토크 및 변속기에서의 드래그 토크를 계산하여 엔진-변속기 인풋기어의 반한정계 2자유도 진동모델과 비틀림 특성을 가진 클러치 디스크의 프리댐퍼 영역에 대해 시뮬레이션을 수행하여 클러치 비틀림 기구의 설계인자인 비틀림 강성, 히스테리시스 토크에 따른 비틀림 진동 저감 효과를 연구하고자 한다.성을 확인하였다. 여기서는 실험실 수준의 평 판모델을 제작하고 실제 현장에서 이루어질 수 있는 진동제어 구조물에 대 한 동적실험 및 FRS를 수행하는 과정과 동일하게 따름으로써 실제 발생할 수 있는 오차나 error를 실험실내의 차원에서 파악하여 진동원을 있는 구조 물에 대한 진동제어기술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile where

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.290-305
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• 2015

To improve the practicality of 'Early warning service about agrometeorological weather hazards' and operation efficiency to deliver site-specific about a lot of land unit possibility of weather hazard occurrence with the suitable counterplan to farmer, site-specific early warning service system that was built at the National Academy of Agricultural Science in Korea passed some of the error supplementation and service's stabilization stage during operation period for trial services from October 2014 to March 2015. Field service system covered about 470 volunteered farmer and 950 lots in Seomjin river downstream areas (part of Gwangyang-si, Hadong-gun, Gurye-gun). This system (Two track system) consists of early warning system (a lot of land unit) to inform farmer by individual text message and dispersal prior alert system that can see the jurisdiction's situation of local government. Individual text message about Seomjin river downstream that is our first study area was launched since $2^{nd}$ March 2015, and online site (http://www.agmet.kr) started business since April 2015. Service offers currently information of farm weather, farm weather hazard, nationwide weather risk and special weather alert, also our system will consistently expand the service target area and contents and improve the service quality until 2017 when our study finished. To prevent crops damage that was caused by crisis situation like farm weather and weather damage offer prior alert about agrometeorological weather harzard to volunteered farmer, thereby our study expects to help the reduction of farm's damage caused by weather derivatives.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.1
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• pp.13-18
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• 2014

Sensor nodes are used for monitoring and collecting the environmental data via wireless sensor network. The wireless sensor network with various sensor nodes draws attention as a key technology in ubiquitous computing. Sensor nodes has very small memory capacity and limited power resource. Thus, it is essential to have energy efficient strategy for the sensor nodes. Since the sensor nodes are operating on the same frequency bands with ISM frequency bands, the interference by the devices operating on the ISM band degrades the quality of communication integrity. In this paper, the convolutional code is proposed instead of ARQ for the error control for the sensor network. The proposed convolutional code was implemented and the BER performance is measured. For the fixed transmitting powers of -19.2 dBm and -25dBm, the BER with various communication distances are measured. The packet loss rate and the retransmission rate are calculated from the measured BER. It is shown that the porposed method obtained about 9~12% and 12-19% reduction in retransmission rate for -19.2 dBm and -25 dBm respectively.