• Clean Technology
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• v.24 no.1
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• pp.9-14
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• 2018

In this study, Material life cycle evaluation was performed to analyze the environmental impact characteristics of TiN-Zr membrane manufacturing process. The software of MLCA was Gabi. Through this, environmental impact assessment was performed for each process. Transition metal nitrides have been researched extensively because of their properties. Among these, TiN has the most attention. TiN is a ceramic materials which possess the good combination of physical and chemical properties, such as high melting point, high hardness, and relatively low specific gravity, high wear resistance and high corrosion resistance. With these properties, TiN plays an important role in functional materials for application in separation hydrogen from fossil fuel. Precursor TiN was synthesized by sol-gel method and zirconium was coated by ball mill method. The metallurgical, physical and thermodynamic characteristics of the membranes were analyzed by using Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDS), X-ray Diffraction (XRD), Thermo Gravimetry/Differential Thermal Analysis (TG/DTA), Brunauer, Emmett, Teller (BET) and Gas Chromatograph System (GP). As a result of characterization and normalization, environmental impacts were 94% in MAETP (Marine Aquatic Ecotoxicity), 2% FAETP (Freshwater Aquatic Ecotoxicity), 2% HTP (Human Toxicity Potential). TiN fabrication process appears to have a direct or indirect impact on the human body. It is believed that the greatest impact that HTP can have on human is the carcinogenic properties. This shows that electricity use has a great influence on ecosystem impact. TiN-Zr was analyzed in Eco-Indicator '99 (EI99) and CML 2001 methodology.

• Journal of Korea Multimedia Society
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• v.16 no.5
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• pp.558-565
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• 2013

Mammography, the process of using X-ray to examine the woman breast, is the one of the effective tools for detecting breast cancer at an early state. In screening mammogram, Computer-Aided Detection(CAD) system helps radiologist to diagnose cases by detecting malignant masses. A mass is an important lesion in the breast that can indicate a cancer. Due to various shapes and unclear boundaries of the masses, detecting breast masses is considered a challenging task. To this end, CAD system detects a lot of regions of interest including normal tissues. Thus it is important to develop the well-organized classifier. In this paper, we propose an enhanced sparse representation (SR) based classifier using Fisher discrimination dictionary learning. Experimental results show that the proposed method outperforms the existing support vector machine (SVM) classifier.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.505-510
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• 2004

In this article, we present an automated system for adjusting the 6 degree of freedom (D.O.F.) circular fixator. The system includes a scheduling software to adjust the Hexapod Circular Fixator (HCF) and an automated strut with the ability of the multiple synchronized motion and independent motion. The HCF was designed to control a 6 D.O.F. Ilizarov fixator and it's mechanism. The HCF adjustment software evaluates each value of altered length of the HCF struts to correct the complex skeletal deformity by using the X-ray data of the patient. The data of HCF adjustment software feed into the automated strut system which provides the scheduled adjustment. Then, the automated strut is synchronized by input data. Also the data of HCF adjustment software can be used to adjust HCF without automated struts. The proposed HCF system was verified by experiments.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.4
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• pp.26-32
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• 1991

Korea Aerospace Research Institute(KARI) performs research on developing the scientific sounding rocket(KSR-420S) for measuring ozone profile and atmosphere layer over korean peninsula. Informations about performances of flighting scientific rocket, that is temperature, strain, acceleration, pressure, rocket attitude and ranging data, and measuring data of ozone, ionosphere and X-ray are transmitted ground system by rocket onboard transmitting system. In this paper, the telemetry ground system which is compatible with the KSR-420S is designed for tracking the trajectory and receiving the incoming signals.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.142-145
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• 1995

스크린-필름 X선 유방조영술(Screen-film X-ray mammography)은 유방암 진단을 위한 기준이 되는 방법으로 독보적인 위치를 차지하고 있다. 그러나 현재 사용되는 스크린-필름 방식 유방조영술은 여러 가지 한계점들이 인식되어 왔으며, 만약 유방 X선 사진(mammogram)이 디지탈 형식으로 곧 바로 얻어진다면 영상의 질(image quality)과 방사선량의 감소 가능성 관점에서 향상될 수 있다는 증거가 있다. 본 논문에서는, 디지탈 유방조영술에 대한 논리적 근거가 제시되고, 스크린 대용으로 개발되고 있는 X-선 검출기들과 이들을 사용한 여러가지 디지탈 유방조영술 시스템들을 분석 전망한다. 디지털 유방조영술을 실용화하기 위해 해결되어야 할 문제점들이 논의된다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.115.2-115.2
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• 2013

10 Gev의 빔에너지를 가지는 4세대 방사광 가속기의 hard X-ray구간에는 약 200 m의 언듈레이터 홀이 건설 중이며, 내부에는 길이 5 m의 언듈레이터와 1m의 언듈레이터 사이구간이 연속적으로 배치되어 있다. 이 구간에는 언듈레이터를 비롯하여 phase shifter, quadrupole, BPM 등이 설치되는 진공용기가 있으며, 이 진공용기는 최적화된 환경을 제공하기 위해서 매우 얇고 긴 형태로 제작되며 각 구간마다 빔손실이 발생하지 않도록 설계가 되어야 한다. 여기에서는 현재 실험 및 설계 중인 언듈레이터 챔버와 사이구간의 진공시스템에 대하여 소개하고, 현재까지 수행한 결과와 앞으로의 진행방향에 대해 다루고자 한다.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.333-343
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• 2023

King oyster mushrooms are one of the major fresh agricultural products which their exports are increasing every year in Korea. Lycoriella ingenua, is notorious insect pest in agriculture, especially in mushroom production. Larvae of L. ingenua cause mainly direct crop damage and adults are vectors of several dangerous fungal pathogens. In this study, the effects of electron beam, X-ray, and gamma-ray irradiation on the development and reproduction of L. ingenua were evaluated. In addition, to find the optimal dose to control L. ingenua in a box filled with king oyster mushrooms, an empirical experiment was conducted for each radiation. As a result, the development and reproduction of L. ingenua were inhibited at 50 Gy for all electron beam, X-ray, and gamma-ray irradiation. Additionally, at the top, middle, and bottom of the export box filled with king oyster mushrooms, the development and reproduction of L. ingenua were inhibited by electron beam with 150 Gy, X-ray with 100 Gy, and gamma-ray with 50 Gy. These results can be provided as basic data for establishing an integrated quarantine management system when exporting mushrooms. It will also contribute to the safety of agricultural products and the strengthening of export competitiveness.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.375-383
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• 2020

This study aimed to propose a methodology for quantitatively analyzing problems resulting from the performance and combination of the ionization chamber when using an automatic exposure control (AEC) and to optimize the performance of the digital radiography (DR). In the experimental method, the X-ray quality of the parameters used for the examination of the abdomen and pelvis was evaluated by percentage average error (PAE) and half value layer (HVL). Then, the stability of the radiation output and the image quality were analyzed by calculating the entrance surface dose (ESD) and entropy when the three ionization chambers were combined. As a result, all of the X-ray quality of the digital radiography used in the experiment showed a percentage average error and a half value layer in the normal range. The entrance surface dose increased in proportion to the combination of chambers, and entropy increased in proportion to the combination of ionization chambers except when three chambers were combined. In conclusion, analysis using entrance surface dose and entropy was found to be a useful method for evaluating the performance and combination problems of the ionization chamber, and the optimal performance of the digital radiography can be maintained when two or less ionization chambers are combined.

• Journal of Powder Materials
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• v.28 no.2
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• pp.143-149
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• 2021

In this study, (GaN)_1-x(ZnO)_x solid solution nanoparticles with a high zinc content are prepared by ultrasonic spray pyrolysis and subsequent nitridation. The structure and morphology of the samples are investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The characterization results show a phase transition from the Zn and Ga-based oxides (ZnO or ZnGa₂O₄) to a (GaN)_1-x(ZnO)_x solid solution under an NH3 atmosphere. The effect of the precursor solution concentration and nitridation temperature on the final products are systematically investigated to obtain (GaN)_1-x(ZnO)_x nanoparticles with a high Zn concentration. It is confirmed that the powder synthesized from the solution in which the ratio of Zn and Ga was set to 0.8:0.2, as the initial precursor composition was composed of about 0.8-mole fraction of Zn, similar to the initially set one, through nitriding treatment at 700℃. Besides, the synthesized nanoparticles exhibited the typical XRD pattern of (GaN)_1-x(ZnO)_x, and a strong absorption of visible light with a bandgap energy of approximately 2.78 eV, confirming their potential use as a hydrogen production photocatalyst.

• Journal of Internet Computing and Services
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• v.17 no.1
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• pp.101-107
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• 2016

Due to the recent advancement in digital imaging technology, development of intervention equipment has become generalize. Video arbitration procedure is a process to insert a tiny catheter and a guide wire in the body, so in order to enhance the effectiveness and safety of this treatment, the high-quality of x-ray of image should be used. However, the increasing of radiation has become the problem. Therefore, the studies to improve the performance of x-ray detectors are being actively processed. Moreover, this intervention is based on the reference of the angiographic imaging and 3D medical image processing. In this paper, we propose a guidance system to support this intervention. Through this intervention, it can solve the problem of the existing 2D medical images based vessel that has a formation of cerebrovascular disease, and guide the real-time tracking and optimal route to the target lesion by intervention catheter and guide wire tool. As a result, the system was completely composed for medical image acquisition unit and image processing unit as well as a display device. The experimental environment, guide services which are provided by the proposed system Brain Phantom (complete intracranial model with aneurysms, ref H+N-S-A-010) was taken with x-ray and testing. To generate a reference image based on the Laplacian algorithm for the image processing which derived from the cerebral blood vessel model was applied to DICOM by Volume ray casting technique. $A^*$ algorithm was used to provide the catheter with a guide wire tracking path. Finally, the result does show the location of the catheter and guide wire providing in the proposed system especially, it is expected to provide a useful guide for future intervention service.