• 대한소아치과학회지
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• 제42권3호
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• pp.209-217
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• 2015

본 연구는 Q-ray view (All in one Bio, Seoul, Korea)가 변연융선이 파괴되지 않은 유구치의 인접면 우식증을 적절히 탐지해 낼 수 있는지 알아보고자 하였다. 두 명의 소아치과의사가 3-9세 사이의 어린이 32명(평균연령 $5.6{\pm}1.3$세)의 유구치 인접면 100개를 시진, Q-ray view, DIAGNOdent (KaVo, Biberach, Germany), 디지털 치근단 방사선사진 촬영으로 평가하였다. 각 검사법과 실제 치료 시 관찰된 인접면 우식증의 진행 정도를 비교하였을 때, 법랑질 우식증에 대한 kappa값은 시진, Q-ray view, DIAGNOdent, 디지털 치근단 방사선사진 촬영 순으로 0.15, 0.10, 0.25, 0.68이었으며, 상아질 우식증에 대한 kappa값은 0.34, 0.56, 0.44, 0.70이었다. Q-ray view는 상아질까지 진행된 유구치의 숨은 인접면 우식증을 탐지하는 데 도움을 줄 수 있는 유용하고 간편한 보조장비가 될 수 있을 것으로 기대된다.

• 한국진공학회지
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• 제10권1호
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• pp.87-92
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• 2001

자기 Fe-Co(C)나노(nano)캡슐과 Fe-Co 나노입자들이 메탄과 혼합기체($H_2$+Ar) 두 종류의 분위기속에서 각각 아크방전으로 제조되었다. 이 두 종류의 초미세 입자들의 특성과 자기적 성질들을 XRD(X-ray Diffraction), Mossbauer 분광, XPS(X-ray Photoelectron Spectroscopy), TEM(transmission Electron Microscopy), EDS(Energy Disperse Spectroscopy), 화학적 분석, 산소량 측정과 자기 측정 등을 통하여 체계적으로 조사하였다. 메탄기체로부터 분해되어 나온 탄소원소가 미세입자들의 상구조, 자기적 상태 그리고 표면 특성들에 끼치는 효과를 아르곤원소를 사용했을 때와 비교하였다. 두 미세입자에서의 Fe/Co 질량비가 약간 다르게 나타났으며 Fe-Co나노입자의 크기가 Fe-Co(C)나노캡슬보다 약 두배였다. 또한 Fe-Co(C)나노캡슐의 포화자화값이 Fe-Co 나노입자보다 약 8% 높았으며 둘 다 유사한 상구조를 보였다. 핵 표면에 쌓인 껍질들이 매우 얇아 XRD측정으로는 그 존재를 탐지하기 어려웠으나 XPS분석을 통하여 그들이 탄소층과 산소층임을 결론지을 수 있었다.

• 한국의학물리학회지:의학물리
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• 제27권3호
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• pp.169-174
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• 2016

The aim of this study is to investigate the delivery accuracy of intensity-modulated radiation therapy (IMRT) plans in the two-headed mode of the ViewRay$^{TM}$ system in comparison with that of the normal operation treatment plan of the machine. For this study, a total of eight IMRT plans and corresponding verification plans were generated (four head and neck, two liver, and two prostate IMRT plans). The delivered dose distributions were measured using ArcCHECK$^{TM}$ with the insertion of an ionization chamber. We measured the delivered dose distributions in three-headed mode (normal operation of the machine), two-headed mode with head 1 disabled, two-headed mode with head 2 disabled, and two-headed mode with head 3 disabled. Therefore, a total of four measurements were performed for each IMRT plan. The global gamma passing rates (3%/3 mm) in three-headed mode, head 1 disabled, head 2 disabled, and head 3 disabled were $99.9{\pm}0.1%$, $99.8{\pm}0.3%$, $99.6{\pm}0.7%$, and $99.7{\pm}0.4%$, respectively. The difference in the gamma passing rates of the three- and two-headed modes was insignificant. With 2%/2 mm, the rates were $96.6{\pm}3.6%$, $97.2{\pm}3.5%$, $95.7{\pm}6.2%$, and $95.5{\pm}4.3%$, respectively. Between three-headed mode and head 3 disabled, a statistically significant difference was observed with a p-value of 0.02; however, the difference was minimal (1.1%). The chamber readings showed differences of approximately 1% between three- and two-headed modes, which were minimal. Therefore, the treatment plan delivery in the two-headed mode of the ViewRay$^{TM}$ system seems accurate and robust.

• Natural Product Sciences
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• 제10권1호
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• pp.32-34
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• 2004

Two 2-phenoxychromones; a rare group of natural products, were isolated from the combined ethylacetate and chloroform fractions of the ethanolic extract of Ononis serrata frossk (Leguminosae) growing in Egypt. Structures were elucidated by chemical, spectroscopic methods as well as single X-ray diffraction analyses. The cytotoxic and antimicrobial effects of the two compounds were examined. It is worth to mention that this is the first report on the isolation of 2-phenoxychromones from the family Leguminosae.

• 대한화학회지
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• 제57권6호
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• pp.721-725
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• 2013

Reaction between 2-pyridinecarboxylic acid (Hpic) and $K_3[Cr(O_2)_4]$ give complex $[Cr(pic)_3].H_2O$ (1) which is characterized by elemental analysis and spectroscopic methods (FT-IR, Raman) and X-ray crystallography. In the crystal structure of 1, chromium atom with coordinated by three nitrogen and three oxygen atoms has a distorted octahedral geometry. Also a water molecule is incorporated in crystal network. Each water molecule acts as hydrogen bond bridging and connects two adjacent complexes by two $O-H{\cdots}O$ hydrogen bonds.

• Restorative Dentistry and Endodontics
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• 제37권3호
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• pp.160-164
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• 2012

Objectives: This study was aimed to investigate the methods to reduce operator's radiation dose when taking intraoral radiographs with portable dental X-ray machines. Materials and Methods: Two kinds of portable dental X-ray machines (DX3000, Dexcowin and Rextar, Posdion) were used. Operator's radiation dose was measured with an 1,800 cc ionization chamber (RadCal Corp.) at the hand level of X-ray tubehead and at the operator's chest and waist levels with and without the backscatter shield. The operator's radiation dose at the hand level was measured with and without lead gloves and with long and short cones. Results: The backscatter shield reduced operator's radiation dose at the hand level of X-ray tubehead to 23 - 32%, the lead gloves to 26 - 31%, and long cone to 48 - 52%. And the backscatter shield reduced operator's radiation dose at the operator's chest and waist levels to 0.1 - 37%. Conclusions: When portable dental X-ray systems are used, it is recommended to select X-ray machine attached with a backscatter shield and a long cone and to wear the lead gloves.

• 한국자동차공학회논문집
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• 제19권6호
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• pp.37-45
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• 2011

As vehicles become more intelligent, in-vehicle networking (IVN) systems such as controller area network (CAN) or FlexRay are essential for convenience and safety of drivers. To expand the applicability of IVN systems, attention is currently being focused on the communication between heterogeneous networks such as body networking and chassis networking systems. A gateway based on message mapping method was developed to interconnect FlexRay and CAN networks. However, this type of gateways has the following shortcomings. First, when a message ID was changed, the gateway must be reloaded with a new mapping table reflecting the change. Second, if the number of messages to be transferred between two networks increase, software complexity of gateway increases very rapidly. In order to overcome these disadvantages, this paper presents FlexRay-CAN gateway based on node mapping method. More specifically, this paper presents a node mapping based FlexRay-CAN gateway operation algorithm along with the experimental evaluation for ID change.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.64-71
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• 2016

Void fraction is an important parameter in the oil industry. This quantity is necessary for volume rate measurement in multiphase flows. In this study, the void fraction percentage was estimated precisely, independent of the flow regime in gas-liquid two-phase flows by using ${\gamma}-ray$ attenuation and a multilayer perceptron neural network. In all previous studies that implemented a multibeam ${\gamma}-ray$ attenuation technique to determine void fraction independent of the flow regime in two-phase flows, three or more detectors were used while in this study just two NaI detectors were used. Using fewer detectors is of advantage in industrial nuclear gauges because of reduced expense and improved simplicity. In this work, an artificial neural network is also implemented to predict the void fraction percentage independent of the flow regime. To do this, a multilayer perceptron neural network is used for developing the artificial neural network model in MATLAB. The required data for training and testing the network in three different regimes (annular, stratified, and bubbly) were obtained using an experimental setup. Using the technique developed in this work, void fraction percentages were predicted with mean relative error of <1.4%.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.334-343
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• 1996

Quality evaluation for food and agricultural products have always been one of the most elusive problems associated with the handling , processing and marketing in a food plant production. In order to detect physical foreign materials in food and agricultural products, non-destructive techniques have been developed for many years. Application of X-ray system to detect physical foreign materials in food and agricultural products could be considered to be a high potential method. Especially , it is impossible to detect internal physical foreign materials by visual inspections. In this study, it was tried to be applied for two different X-ray devices. Soft X-ray system with CdTe sensor and X-ray CT scanner were evaluated for advantage of the detection of non-meltallic foreign materials in food and agricultural products . Though the soft X-ray is not a high energy radiation, it is possible to detect small different density in a material. The CdTe sensor has a high resolution for t e soft X-ray energy region. The density characteristics of foods and foreign material were expressed region. The density characteristics of foods and foreign materials were expressed as a soft X-ray energy spectrum. The energy spectrum was analyzed by a personal computer with a multi-channel analyzer. X-ray CT scanner can provide visual image and analyze by three dimensional information inside food and agricultural products. The X-ray CT scanner using as a medical equipment was used to detect a foreign material. The density characteristics of food and foreign materials in food were tried to be detected by the threshold value on the basis of the CT numbers. The soft X-ray absorption characteristics for acrylin plates and distilled water were obtained and could be found the possibility of detecting a small physical foreign materials such as a plastic wrapping film , a stone and grasshopper in food and agricultural products.

• Journal of Astronomy and Space Sciences
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• 제29권1호
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• pp.93-96
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• 2012

There are observational difficulties determining dynamical masses of binary star components in the upper HR diagram both due to the scarcity of massive binary systems and spectral and photometric contamination produced by the strong wind outflows in these systems. We discuss how variable X-ray emission in these systems produced by wind-wind collisions in massive binaries can be used to constrain the system parameters, with application to two important massive binaries, Eta Carinae and WR 140.