• 한국결정성장학회지
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• 제10권6호
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• pp.418-424
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• 2000

sol-gel 방법으로 순수한 $TiO_2$와 Pb가 10 mol % 첨가된 $TiO_2(Pb_xTi_{1-x}O_2$(x = 0.1)) 분말과 박막을 제조하였다. $TiO_2$제조에는 titanium isopropoxide와 ethanol이 $Pb_xT_{1-x}O_2$(x = 0.1) 제조에는 lead acetate trihydrate와 titanium triisopropoxide monoacethylacetonate이 사용되었다. P-type Si(100) wafer, ITO glass 기판 위에 sol-gel spin-coating방법으로 박막을 형성시켰으며 상(phase)의 형성과 결정화를 위해서 400~$800^{\circ}C$에서 열처리하였다 준비된 분말 및 박막의 특성은 TGA/DTA, XRD, SEM, UV-visible spectrometer를 이용하여 검토하였다. XBD 측정 결과 A(101)면으로 우선 배향된 다결정성 anatase 형의 분말 및 박막을 얻을 수 있었고 Pb가 첨가된 박막에 대한 d-값의 작은 변화가 관측되었는데 이는 Pb가 $TiO_2$살창으로 들어왔음을 의미한다. UV-visible투과 스펙트럼측정 결과에 의하면 Pb가 첨가된 박막에서 투과 스펙트럼의 흡수파장이 장파장쪽으로 이동하는데 이는 Pb가 첨가되면 밴드 갭의 축소가 일어남을 의미한다.

• 대한방사선치료학회지
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• 제19권2호
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• pp.99-106
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• 2007

목 적: 방사선치료 중 환자의 자세나 해부학적 구조상 장기의 움직임과 치료 시 환자를 조준하면서 치료부위의 변화가 다양하게 발생할 수 있다. 이와 같은 요인은 종양부위나 정상조직에 대한 선량분포에 영향을 미치게 된다. 이는 치료계획용전산 화장비에 의해 계산된 선량이 실제임상 치료 시 서로 다른 선량이 조사될 수 있다. 인체의 생리학적인 움직임과 장기 내의 움직임 등은 고정기구나 정확한 환자의 치료준비에 의해서 치료조준의 정확성을 높일 수 있다. 본 연구의 목적은 토모영상을 통해 육안적종양체적(Gross tumor volume, GTV)과 장기의 치료 간에 발생하는 차이점을 평가하고자 한다. 대상 및 방법: 본원환자로서 직장풍선을 이용하여 치료하는 전립선암 환자 3명을 대상으로 하였고, 3달 동안 영상 자료를 수집 하였다. 각 환자마다 치료횟수 26회에 대한 토모영상을 획득하였고, 총 76회의 토모영상을 수집하였다. 각각의 토모영상은 전산화단층촬영모의치료(Computed tomography simulation, CT-simulation) 시의 중심점을 이용하였고, 매 치료 시 직장풍선에 60 cc의 공기주입 후 항문 가장자리에서 6 cm 깊이에 고정하여 전립선의 움직임을 고정시킨 후 치료 전에 토모영상을 획득하였다. 토모영상은 5 mm 두께로 영상을 획득하였다. 본 연구의 분석방법으로 CT-simulation와 MVCT (Megavoltage computed tomography, MVCT)의 융합을 위하여 납 볼을 이용하여, 토모치료의 3가지 영상융합방법으로 Bone technique, bone/tissue technique, full image technique을 이용하여 치료준비(setup)의 오차를 분석하였다. 영상융합은 눈에 보이는 납 볼 기준으로 융합하고, CT-simulation 시 획득한 영상에 MVCT에서 얻어진 영상을 융합하여, 뼈와 직장풍선, GTV을 매 치료 시 각각 비교하였다. 최초 CT-simulation 시 기준점을 중심으로 평균과 표준편차는 X, Y, Z, Roll에 대하여 각각의 환자를 분석하였다. 결 과: 분석결과 각각의 방법에 위해서 직장풍선의 변화는 확연히 다르게 나타났다. 정량적으로 뼈를 이용한 영상융합 결과 X방향으로 최대 8 mm, Y방향으로 4 mm의 움직임을 보였다. 직장풍선 기준으로 영상융합 한 결과 X, Y 방향으로 6 mm, 16 mm로 분석 되었다. 한 환자의 경우 16 mm 이상의 움직임을 보였는데, 이는 직장내의 공기나 분비물에 의한 움직임으로 분석 되었다. GTV 기준분석 결과 X 방향으로 2.7$\sim$6.6 mm, 4.3$\sim$7.8 mm가 Y방향으로 움직임을 보였다. 본 연구에서 Roll에 대한 분석결과 영상융합과 분석상에서 확연한 차이점은 없었다. 분석결과 뼈 기준의 분석결과 0.37$\pm0.36^{\circ}$, GTV 기준분석 결과 0.34$\pm0.38^{\circ}$의 회전을 보였다.

• Journal of Ecology and Environment
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• 제44권1호
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• pp.1-7
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• 2020

Background: Fish body size is a major determinant of freshwater trophic interactions, yet only a few studies have explored the relationship between the fish body size and trophic interactions in river upstream. In this study, we investigated the relationship between the body size and trophic position (TP) of Coreoperca kawamebari (Temminck & Schlegel, 1843) in an upstream of the Geum River. Results: A stable isotope analysis (based on δ¹⁵N) was used to determine the TP based on the body size of C. kawamebari. The regression analysis (n = 33, f = 63.840, r² = 0.68) clearly showed the relationship between the body length and TP of C. kawamebari. The TP of C. kawamebari was clearly divided by body size into the following classes: individuals of size < 10 cm that feed on insects and individuals of size > 10 cm feed on juvenile fish. This selective feeding is an evolutionarily selective tendency to maximize energy intake per unit time. Furthermore, the diet shift of C. kawamebari was led by different spatial distributions. The littoral zone was occupied by individuals of size < 10 cm, and those of size > 10 cm were mainly in the central zone. The littoral zone can be assumed to be enriched with food items such as ephemeropterans and dipterans. Conclusion: The TP of C. kawamebari, as a carnivorous predator, will have a strong influence on biotic interactions in the upstream area of the Geum River, which can lead to food web implication.

• 대한방사선치료학회지
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• 제10권1호
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• pp.88-93
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• 1998

Multileaf collimator is essential equipment in conformal radiation therapy, however the use is limitted by increase of penumbra width and undulating dose distribution at the field edge. The purpose of this study is to improve the penumbra and dose distribution in the multileaf collimator field edge. Measurement were performed with X-omat V film in solid water phantom using 6MV photon beam from Siemens linear accelerator. All the measurement were made along the central axis of $5{\times}5cm,\;10{\times}10cm$ circular field for constant SSD of 100 cm. To improve the penumbra and dose distribution collimator was rotated by 15 degrees from 0 to 90 degrees (collimator rotation method) and center was shifted to the longitudinal direction by fourth of lead width (center shift method). We compare the penumbra and dose distribution at the field edge to alloy block. Dose distribution and penumbra width at the feild edge of MLC showed undulated dose pattern and increased penumbra compared with alloy block. However, in the collimator rotation method and center shift method we abtained simular results with alloy block. Through the study we expected that clinical use of MLC will be increase.

• International Journal of Computer Science & Network Security
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• 제24권2호
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• pp.158-168
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• 2024

There is hardly any person in modern times who has not taken soft drinks instead of drinking water. The rate of people taking soft drinks being surprisingly high, researchers around the world have cautioned from time to time that these drinks lead to weight gain, raise the risk of non-communicable diseases and so on. Therefore, in this work an image-based tool is developed to monitor the nutritional information of soft drinks by using deep convolutional neural network with transfer learning. At first, visual saliency, mean shift segmentation, thresholding and noise reduction technique, collectively known as 'pre-processing' are adopted to extract the location of drinks region. After removing backgrounds and segment out only the desired area from image, we impose Discrete Wavelength Transform (DWT) based resolution enhancement technique is applied to improve the quality of image. After that, transfer learning model is employed for the classification of drinks. Finally, nutrition value of each drink is estimated using Bag-of-Feature (BoF) based classification and Euclidean distance-based ratio calculation technique. To achieve this, a dataset is built with ten most consumed soft drinks in Bangladesh. These images were collected from imageNet dataset as well as internet and proposed method confirms that it has the ability to detect and recognize different types of drinks with an accuracy of 98.51%.

• IEIE Transactions on Smart Processing and Computing
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• 제2권5호
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• pp.310-316
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• 2013

This paper reports a sinusoidal $180^{\circ}$ drive for a permanent magnet (PM) brushless motor employing automatic angle compensator to suppress the driving loss during the wide-range load operation. The proposed drive of the sinusoidal $180^{\circ}$ PM Brushless motor reduced the amplitude of the 3-phase current by compensating for the lead-angle of the fundamental waves of the 3-phase PWM signal. The conventional lead-angle method was implemented using the fixed angle or memorized table, whereas the proposed method was automatically compensated by calculating the angle of the current and voltage signal. The algorithm of the proposed method was verified in a 30 W PM brushless motor system using a PSIM simulator. The efficiency of the conventional method was decreased 90 % to 60 %, whereas that of proposed method maintained approximately 85 % when the load shift was 0 to $0.02N{\cdot}m$. Using an FPGA prototype, the proposed method was evaluated experimentally in a 30 W PM brushless motor system. The proposed method maintained the minimum phase RMS current and 79 % of the motor efficiency under 0 to $0.09N{\cdot}m$ load conditions. The proposed PM brushless motor driving method is suitable for a variety of applications with a wide range of load conditions.

• Radiation Oncology Journal
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• 제1권1호
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• pp.29-36
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• 1983

The treatment of tumors along curved surfaces with stationary electron beams using cone collimation may lead to non-uniform dose distributions due to a varying air gap between the cone surface and patient. For large tumors, more than one port may have to be used in irradiation of the chest wall, often leading to regions of high or low dose at the junction of the adjacent ports. Electron-beam arc therapy may elimination many of these fixed port problems. When treating breast tumors with electrons, the energy of the internal mammary port is usually higher than that of the chest wall port. Bolus is used to increase the skin dose or limit the range of the electrons. We invertiaged the effect of various arc beam parameters in the isodose distributions, and combined into a single arc port for adjacent fixed ports of different electron beam eneries. The higher fixed port energy would be used as the arc beam energy while the beam penetration in the lower energy region would be controlled by a proper thickness of bolus. We obtained the results of following: 1. It is more uniform dose distribution of electron to use rotation than stationary irradiation. 2. Increasing isocenter depth on arc irradiation, increased depth of maximum dose, reduction in surface dose and an increasing penetration of the linear portion of the curve. 3. The deeper penetration of the depth dose curve and higher X-ray background for the smaller field sized. 4. If the isocenter depth increase, the field effect is small. 5. The decreasing arc beam penetration with decreasing isocenter depth and the isocenter depth effect appears at a greater depth as the energy increases. 6. The addition of bolus produces a shift in the penetration that is the same for all depths leaving the shape of the curves unchanged. 7. Lead strips 5 mm thick were placed at both ends of the arc to produce a rapid dose drop-off.

• 센서학회지
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• 제3권2호
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• pp.33-39
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• 1994

냄새물질 특히, 환경오염물질의 측정을 위한 수정진동자를 이용한 센서 시스템을 수정진동자 표면에 여러가지 인지질과 활성탄 그리고 납계열 무기안료를 피막시켜 만들었다. 포스파티딜 콜린을 누적한 9MHz 수정진동자의 각종 유기가스에 대한 응답 특성을 살펴보았다. 인지질막의 특성에 기초한 서로 다른 냄새물질사이의 친화력에 대하여 설명할 수 있었다. 냄새물질은 누적한 지질막에 의존하는 공진주파수 변화 패턴과 응답면적에서 계산되어지는 상대적인 응답 세기를 서로 비교하여 확인할 수 있었다. 납계열 무기안료를 누적한 수정진동자를 이용하여 황화물의 검출이 가능함을 알 수 있었다. 이 결과, 여러가지 지질을 누적한 수정진동자를 이용하여 그 응답패턴을 비교한다면 냄새물질의 분석이 가능함을 알았다.

• 한국세라믹학회지
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• 제53권2호
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• pp.145-149
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• 2016

$(Bi_{1/2}Na_{1/2})_{0.94}Ba_{0.06}(Ti_{1-x}Nb_x)O_3$ (BNBTxNb) ceramics were investigated in terms of the crystal structure as well as the ferroelectric, dielectric, and piezoelectric properties. While little change was observed in the microstructure except for a slight decrease in the average grain size, a significant change was noticed in the temperature dependence of dielectric and piezoelectric properties. It was shown that the property changes are closely related to the downward shift in the position of the ferroelectric-to-relaxor transition temperature with increasing amount of Nb doping. A special emphasis is put on the fact that Nb doping is so effective at decreasing the ferroelectric-to-relaxor transition temperature that even at no more than 2 at.% Nb addition, the transition temperature was already brought down slightly below room temperature, resulting in the birth of a large strain at 0.46 %, equivalent to $S_{max}/E_{max}=767pm/V$.

• Journal of Veterinary Science
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• 제21권4호
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• pp.67.1-67.11
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• 2020

Background: Tibial tuberosity transposition (TTT) causes caudalization of the patellar ligament insertion in canine medial patellar luxation, which can lead to increases in patellofemoral contact pressure. Objectives: The purpose of this study is to confirm the effect of patellofemoral contact mechanics after craniolateral and caudolateral transposition of tibial tuberosity in normal canine hindlimbs. Methods: Craniolateral and caudolateral transposition of tibial tuberosity was performed in 5 specimens, respectively. The pressure was measured in the specimen before TTT, and then in the same specimen after TTT. In this process, data was obtained in 10 specimens. The measurement results were output as visualization data through the manufacturer's software and numerical data through spreadsheet. Based on these 2 data and the anatomical structure of the patellofemoral joint (PFJ) surface, whole measurement area was analysed by dividing into medial, lateral and central area. Results: In craniolateralization of tibial tuberosity, total, medial, central contact pressure was decreased and lateral contact pressure was not statistically changed lateral contact pressure than normal PFJ. In caudolateralization of tibial tuberosity, total, lateral contact pressure was increased and medial contact pressure was not statistically changed than normal PFJ. Although not statistically significant changed, central contact pressure in caudolateralization of tibial tuberosity was increased in all 5 specimens. Conclusions: These results imply that traditional TTT, prone to caudal shift of patellar tendon, can increase retropatellar pressure may lead to various complications and diseases of the stifle joint.