• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.3
• /
• pp.273-281
• /
• 2002

Determination of sediment type is generally based on ground truthing. This method, however, provides information only for the limited sites. Recent developments of remote classification of seafloor sediments made it possible to obtain continuous profiles of sediment types. QTC View system, which is an acoustic instrument providing digital real-time seabed classification, was used to classify seafloor sediment types in the Suyoung Bay, Pusan. QTC View was connected to 50 kHz echo sounder, All parameters of QTC View and echo sounder are uniformly kept during survey. By ground truthing, the sediments are classified into seven types, such as slightly gravelly sand, slightly gravelly sandy mud, gravelly muddy sand, clayey sand, sandy mud, slightly gravelly muddy sand, and rocky bottom. By the first remote classification using QTC View, four sediment types are clearly identified, such as slightly gravelly sand, gravelly mud, slightly gravelly muddy sand, and rocky bottom. These are similar to the result of the second survey. Also the result of remote classification matches well with that of ground truthing, but for sediment type determined by minor component. Therefore, QTC View can effectively be used for remote classification of seafloor sediments.

• Journal of the Korean Society of Radiology
• /
• v.11 no.2
• /
• pp.123-130
• /
• 2017

Patients diagnosed with the serious disease of cancer may have anxiety and fear of closed spaces while receiving radiation therapy. This study investigated patients receiving treatment based on Linac and Tomotherapy to look into this anxiety and fear. Study method was survey. The survey was performed according to treatment duration (treatment within 5 minutes, 10 minutes, over 20 minutes, and over 30 minutes). The patients were also surveyed about any experience of changing treatment rooms or machines due to machine failure. A total of 200 survey questionnaires with full answers were researched in this study. As a result, it was found that the less the patients' experience on radiation therapy, the higher their anxiety was. The dominating reason for this result was because the patients expected possible pain during the treatment process. In terms of treatment machine, Linac showed the highest anxiety of all for the openness of its patient stand. The most stable status was found in the case of treatment between 20 minutes and 30 minutes using Tomotherapy. The reason was the coziness of Tomotherapy machine. In the case of receiving the treatment for over 30 minutes, patients felt anxious for the isolation from the outside. The study findings are expected to serve as the necessary data for quality medical service with enhanced patient satisfaction in the clinical field.

• Journal of the Korean Society of Radiology
• /
• v.11 no.7
• /
• pp.637-645
• /
• 2017

The objective of this study was to find the optimum test device for the cerebral blood vessels by comparing and analyzing the SNR and CNR methods for images of three devices (i.e., MRA, CTA, and DSA). The study targeted 90 patients who underwent cerebral angiography from November 2016 to May 2017. The measuring parts were measured by using Rt MCA, Lt MCA, and ACA Image J. The results of quantitative analysis showed that the mean SNR of MRA, the CNR of MRA, the signal strength of MRA, the mean SNR of CTA, the CNR of CTA, the signal strength of CTA, the SNR of DSA, the CNR of DSA, and the signal strength of DSA were evaluated as 254.87, 178.13, 326.81, 74.75, 62.2, 356.66, 26.85, 25.89, and 4400.69, respectively (p<0.05). As a result, both SNR and CNR methods measured it in the order of MRA>CTA>DSA. Statistical significance was determined by using ANOVA analysis at p<0.05 and Bonferroni method was used as a post-hoc analysis SPSS. In conclusion, the results of this study revealed that the optimum imaging devices were MRA, CTA, and DSA after evaluating randomly selected patients with cerebrovascular disease.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.109-110
• /
• 2014

주사전자현미경(Scanning Electron Microscopy: SEM)은 고체상태에서 미세조직과 형상을 관찰하는 데에 가장 다양하게 쓰이는 분석기기로서 최근에 판매되고 있는 고분해능 SEM은 수 나노미터의 분해능을 가지고 있다. 그리고 SEM의 초점심도가 크기 때문에 3차원적인 영상의 관찰이 용이해서 곡면 혹은 울퉁불퉁한 표면의 영상을 육안으로 관찰하는 것처럼 보여준다. 활용도도 매우 다양해서 금속파면, 광물과 화석, 반도체 소자와 회로망의 품질검사, 고분자 및 유기물, 생체시료 nnnnnnnnn와 유가공 제품 등 모든 산업영역에 걸쳐 있다(Fig. 1). 입사된 전자빔이 시료의 원자와 탄성, 비탄성 충돌을 할 때 2차 전자(secondary electron)외에 후방산란전자(back scattered electron), X선, 음극형광 등이 발생하게 되는 이것을 통하여 topography (시료의 표면 형상), morphology(시료의 구성입자의 형상), composition(시료의 구성원소), crystallography (시료의 원자배열상태)등의 정보를 얻을 수 있다. SEM은 2차 전자를 이용하여 시료의 표면형상을 측정하고 그 외에는 SEM을 플랫폼으로 하여 EDS (Energy Dispersive X-ray Spectroscopy), WDS (Wave Dispersive X-ray Spectroscope), EPMA (Electron Probe X-ray Micro Analyzer), FIB (Focus Ion Beam), EBIC (Electron Beam Induced Current), EBSD (Electron Backscatter Diffraction), PBMS (Particle Beam Mass Spectrometer) 등의 많은 분석장치들이 SEM에 부가적으로 장착되어 다양한 시료의 측정이 이루어진다. 이 중 결정구조, 조성분석을 쉽고 효과적으로 할 수 있게 하는 X선 분석장치인 EDS를 SEM에 일체화시킨 장비와 EDS 및 PBMS를 SEM에 장착하여 반도체 공정 중 발생하는 나노입자의 형상, 성분, 크기분포를 측정하는 PCDS(Particle Characteristic Diagnosis System)에 대해 소개하고자 한다. - EDS와 통합된 SEM 시스템 기본적으로 SEM과 EDS는 상호보완적인 기능을 통하여 매우 밀접하게 사용되고 있으나 제조사와 기술적 근간의 차이로 인해 전혀 다른 방식으로 운영되고 있다. 일반적으로 SEM과 EDS는 별개의 시스템으로 스캔회로와 이미지 프로세싱 회로가 개별적으로 구현되어 있지만 로렌츠힘에 의해 발생하는 전자빔의 왜곡을 보정을 위해 EDS 시스템은 SEM 시스템과 연동되어 운영될 수 밖에 없다. 따라서, 각각의 시스템에서는 필요하지만 전체 시스템에서 보면 중복된 기능을 가지는 전자회로들이 존재하게 되고 이로 인해 SEM과 EDS에서 보는 시료의 이미지의 차이로 인한 측정오차가 발생한다(Fig. 2). EDS와 통합된 SEM 시스템은 중복된 기능인 스캔을 담당하는 scanning generation circuit과 이미지 프로세싱을 담당하는 FPGA circuit 및 응용프로그램을 SEM의 회로와 프로그램을 사용하게 함으로 SEM과 EDS가 보는 시료의 이미지가 정확히 일치함으로 이미지 캘리브레이션이 필요없고 측정오차가 제거된 EDS 측정이 가능하다. - PCDS 공정 중 발생하는 입자는 반도체 생산 수율에 가장 큰 영향을 끼치는 원인으로 파악되고 있으며, 생산수율을 저하시키는 원인 중 70% 가량이 이와 관련된 것으로 알려져 있다. 현재 반도체 공정 중이나 반도체 공정 장비에서 발생하는 입자는 제어가 되고 있지 않은 실정이며 대부분의 반도체 공정은 저압환경에서 이루어지기에 이 때 발생하는 입자를 제어하기 위해서는 저압환경에서 측정할 수 있는 측정시스템이 필요하다. 최근 국내에서는 CVD (Chemical Vapor Deposition) 시스템 내 파이프내벽에서의 오염입자 침착은 심각한 문제점으로 인식되고 있다(Fig. 3). PCDS (Particle Characteristic Diagnosis System)는 오염입자의 형상을 측정할 수 있는 SEM, 오염입자의 성분을 측정할 수 있는 EDS, 저압환경에서 기체에 포함된 입자를 빔 형태로 집속, 가속, 포화상태에 이르게 대전시켜 오염입자의 크기분포를 측정할 수 있는 PBMS가 일체화 되어 반도체 공정 중 발생하는 나노입자 대해 실시간으로 대처와 조치가 가능하게 한다.

• Journal of radiological science and technology
• /
• v.38 no.4
• /
• pp.355-363
• /
• 2015

Advancement in the medical field provides an opportunity for the development of medical equipment and also enable accurate diagnosis for the inspection and the treatment of diseases. The aging of equipment due to the frequent operation produce uncertainty in the patient exposure dose, so a quality control was implemented by establishing a safety management system on a regular basis. The x-ray tube voltage (kVp), which is directly involved in the patient exposure dose and the life of the equipment, needs periodic performance for the quality control, but it has a limitation due to the time and the cost. In this study, we proposed a new method for measuring the kVp with ease by using the Y and Cu to solve the problem of the time and cost. We also evaluated the usefulness and the effectiveness of the new method and its accuracy through the kVp measurement. After securing the condition, the amount of the tube current and evaluating the usefulness and effectiveness of kVp measured using Y and Cu. The density range used was at 0.5-1.0, kVp was in the range of ${\pm}10%$, then, we recorded the change in concentration as % of Y and Cu. This experiment showed that when Cu and Y was at 75 kVp, concentration was the same, and when the kVp was changed to 65 ~ 85 %, a gradual increase in concentration to 85 ~ 110 % was noted.

• Journal of Korea Technology Innovation Society
• /
• v.15 no.2
• /
• pp.443-460
• /
• 2012

Technology is closely related to industrial development and various studies have been performed to understand the linked structure for knowledge flow between the technology and industry. The research, however, wasn't carried out to flow for Korea National Research and Development projects. In this study, linked structure for technology-industry was discussed by utilizing patent data performed in actual National R&D using NTIS Information of the national research and development, and then it was analyzed how knowledge flows between the technology and industry are flowing. It should be defined that the individual applications expected by researchers at the start of the research and technology-industry applications actually applied from the research performances after research was completed. As a result, it was confirmed in most projects the flow of knowledge was occurring to predicted industries before the start of the R&D. However, the technology was applied to unexpected industry in three industries such as Y09(medical, precision and optical instruments), Y10(electrical and mechanical equipment), Y11(automotive and transportation equipment). The results of this study will be able to contribute to planning for efficient investment strategy of technology-industry by investigating the technology-industry knowledge flow relations of national R&D projects.

• Investigative Magnetic Resonance Imaging
• /
• v.2 no.1
• /
• pp.67-72
• /
• 1998

The mapping of the spin-spin relaxation time T2 in pixel-by-pixel was suggested as a quantitative diagnostic tool in medicine. although the CPMG pulse sequence has been known to be the best pulse sequence for T2 measurement in physics NMR, the supplied pulse sequence by the manufacture of MRI system was able to obtain the maximum of 4 CPMG images. Eight or more images with different echo time TEs are required to construct a reliable T2 map, so that two or more acquisitions were required, which easily took more than 10 minutes. 4-echo CPMG imaging pulse sequence was modified to generate the maximum of 8 MR images with evenly spaced echo time TEs. In human MR imaging, since patients tend to move at least several pixels between the different acquisitions, 8-echo CPMG imaging sequence reduces the acquisition time and may remove any mis-regitration of each pixels signal for the fitting of T2. The resultant T2 maps using the theoretically simulated images and using the MR images of the human brain suggested that 8 echo CPMG sequence with short echo spacing such as 17-20 msec can give the reliable T2 map.

• Journal of Navigation and Port Research
• /
• v.39 no.4
• /
• pp.299-305
• /
• 2015

Modbus is a serial communications protocol, it has since become a practically standard communication protocol, and it is now a commonly available means of connecting industrial electronic devices. Therefore, it can be connected with all devices using Modbus protocol to the measurement and remote control on the ships, buildings, trains, airplanes and etc.. In this paper, we add the Modbus communication protocol to the existing lighting controller sensitivity to enable verification and remote control by external environmental factors, and also introduces a fuzzy inference system was configured by external environmental factors to control LED lighting. External environmental factors of temperature, humidity, illuminance value represented by the LED through a fuzzy control algorithm, the values accepted by the controller through the sensor. Modbus is using the RS485 Serial communication with other devices connected to the temperature, humidity, illumination and LED output status check is possible. In addition, the remote user is changed to enable it is possible to change the RGB values in the desired color change. Produced was confirmed that the LED controller output is based on the temperature, humidity and illumination.

• Journal of Navigation and Port Research
• /
• v.41 no.6
• /
• pp.395-400
• /
• 2017

As a serial communications protocol, Modbus has become a practically standard communication protocol and is now a commonly available means of connecting industrial electronic devices. Therefore, all devices can be connected using the Modbus protocol with the measurement and remote control on ships, buildings, trains, airplanes and more. The existing Modbus that has been used is based on serial communication. Modbus TCP uses Ethernet communication based on TCP / IP which is the most widely used Internet protocol today; so, it is faster than serial communication and can be connected to the Internet of Things. In this paper, we designed an algorithm to control LED lighting in a wireless Wi-Fi environment using the Modbus TCP communication protocol, and designed and implemented a LED controller circuit that can check external environmental factors and control remotely through the integrated management system of a ship. Temperature, humidity, current and illuminance values, which are external environmental factors, are received by the controller through the sensors, and these values are communicated to the ship's integrated management system via the Modbus protocol. The Modbus can be connected to Master devices via TCP communication to monitor temperature, humidity, current, illuminance status and LED output values, and also users can change the RGB value remotely in order to change to the desired color. In addition, in order to confirm the implementation of the controller, we developed a simulated ship management system to monitor the temperature, humidity, current and illumination conditions, and change the LED color of the controller by changing the RGB value remotely.

• Journal of the Korean Institute of Gas
• /
• v.2 no.4
• /
• pp.79-84
• /
• 1998

This paper describes the minimum ignition limit voltages for LPG-Air 5.25[Vol$\%$] mixture gas by discharge sparks in radio-frequency limits using RF power supply and IEC type ignition spark apparatus. As a result, the minimum ignition limit voltages is increased in proportional to the rate of increasing of frequency in LPG-Air mixture gas. Especially, the minimum ignition limit voltages increase remarkably between 3[KHz] and 10[KHz]. It is considered that ignition is caused by one discharge until 3[KHz] and, beyond 3[KHz] ignitiof is caused by more than two discharges. The reason is analyzed that energy loss is caused by existing pause interval between discharges. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof RF machines which are applied tole-equipments and detectors used in dangerous areas but also for datum for its equipment tests.