• Progress in Medical Physics
• /
• 제26권2호
• /
• pp.93-98
• /
• 2015

The purpose of this study is to see the usefulness of lead apron for critical organs near the breast under examining. For clinical experiment, 30 female volunteers who agreed to their participation in the experiments, were chosen and divided into two groups, 15 in group A and 15 in group B respectively. group A is to see whether each side of breast under mammography affects to other side glandular on the critical organs is same, because it is not allowed to scan the both breast for same person or to scan repeatedly. Group B is to see the effectiveness of lead apron during the mammography of right breast. Glass dosimeters were placed on the thyroid, the contralateral breast, and lower abdomen where near the breast during examining. The average glandular doses on the surface in mammography of the thyroid gland, the contralateral breast, the lower abdomen were 0.0692 mGy, 0.6790 mGy, and 0.0122 mGy, respectively, which was an extremely low level of glandular dose. In group B, as to the thyroid gland, average dose was decreased from 0.0922 mGy to 0.0158 mGy. The average dose of contralateral breast was decreased from 0.8575 mGy to 0.0286 mGy. The average doses of lower abdomen was decrease 0.0150 mGy to 0.0173 mGy. As to the lower abdomen, dose decreased from 0.0150 mGy before the use of an apron down to 0.0173 mGy after the use. As p-value was under 0.05, statistically significant difference was observed between the two groups. Wearing an apron can have the protective effects on the thyroid gland up to 20 times lower than not wearing one. Besides, it is also necessary to protect the other breast during the examination by wearing one.

• Korean Journal of Environment and Ecology
• /
• 제25권1호
• /
• pp.1-9
• /
• 2011

In order to analyze the change in home ranges depending on the reproductive stage of Pipistrellus abramus, radio-tracking was carried out for a total of 9 individuals, 3 individuals each, by dividing stages into a pregnancy stage, lactation stage, and post-lactation stage from May to August 2009. For radio-telemetry, 0.38g transmitters, R2000 receivers and 3-element Yagi antennas were used. Pipistrellus abramus were captured using a double-stacked mist net and a harp-trap. Analysis of home ranges used a SHP File and ArcGIS 3.3 for GIS, and used a Kernel Home Range Method(KHR) and a Minimum Convex Polygon(MCP) Method for analysis. Home ranges at the pregnancy stage were MCP 100% $13.46{\pm}1.84ha$, MCP 95% $12.28{\pm}2.15ha$, KHR 50% $3.00{\pm}0.71ha$, and home ranges at the lactation stage were MCP 100% $8.13{\pm}0.23ha$, MCP 95% $7.73{\pm}0.63ha$, KHR 50%$1.84{\pm}1.05ha$. Home ranges at the post-lactation stage were MCP 100% $125.58{\pm}97.77ha$, MCP 95% $123.89{\pm}97.73ha$, KHR 50% $28.61{\pm}26.78ha$. As a result, home ranges of pipistrellus abramus showed a significant difference in all of the MCP 100%, MCP 95%, KHR 50% depending on reproductive stages, being largest in the post-lactation stage and smallest in the lactation stage.

• Journal of Animal Science and Technology
• /
• 제52권4호
• /
• pp.337-346
• /
• 2010

We report non-specific immune responses and disease resistance against Vibrio anguillarum, Streptococcus iniae and Edwardsiella tarda by dietary supplementation of fermented garlic powder (FGP) in olive flounder for the first time. Four isonitrogenous (45% crude protein) and isocaloric (17.1 MJ/kg) diets were formulated to have 0%, 0.5%, 1% and 2% of the FGP (G-0, G-0.5, G-1 and G-2). The experimental diets were fed to juvenile olive flounder averaging 23.4 g in triplicate groups (90 fish/group) in a flow-through system. After a five-week feeding trial, healthy fish with similar sizes from each tank were selected and injected with 1 ml of three bacteria each to evaluate disease resistance of the fish. During the 5-week feeding trial, the weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio, and survival of the fish were not significantly affected by the experimental diets. However, feed intake was significantly lower (P<0.05) in the fish fed the G-2 diet compared with the control group. Hemoglobin, myeloperoxidase activity, cholesterol and HDL-cholesterol were not different between the dietary groups. However, hematocrit, nitroblue tetrazolium (NBT) activity, and lysozyme activity were increased (P<0.05) with an increment of dietary FGP. Plasma triglyceride of the fish fed the G-0.5 diet was significantly lower than that of fish fed the control diet. The cumulative mortality was lower in the fish fed diets containing FGP compared with the control group in the challenge test except for the bacteria Edwardsiella tarda. The results in this study indicate that dietary supplementation of FGP can enhance the non-specific immune responses and disease resistance of olive flounder against V. anguillarum and S. iniae.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• 제24권6호
• /
• pp.229-236
• /
• 2014

A stoichiometric mixture of evaporating materials for $MnAl_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MnAl_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MnAl_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.7920eV-5.2729{\times}10^{-4}eV/K)T^2/(T+786 K)$. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (${\gamma}$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation (MAPD) and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in S vapour compare with in Mn, Al, air and vacuum vapour. Then we obtained the sensitivity of 0.93, the value of pc/dc of $1.10{\times}10^7$, the MAPD of 316 mW, and the rise and decay time of 14.8 ms and 12.1 ms, respectively.

• Journal of IKEEE
• /
• 제18권4호
• /
• pp.552-558
• /
• 2014

This paper suggests how to design a ZigBee-chip-based communication module to remotely measure radiation level. The suggested communication module consists of two control processors for the chip as generally required to configure a ZigBee system, and one chip module to configure a ZigBee RF device. The ZigBee-chip-based communication module for remote radiation measurement consists of a wireless communication controller; sensor and high-voltage generator; charger and power supply circuit; wired communication part; and RF circuit and antenna. The wireless communication controller is to control wireless communication for ZigBee and to measure radiation level remotely. The sensor and high-voltage generator generates 500 V in two consecutive series to amplify and filter pulses of radiation detected by G-M Tube. The charger and power supply circuit part is to charge lithium-ion battery and supply power to one-chip processors. The wired communication part serves as a RS-485/422 interface to enable USB interface and wired remote communication for interfacing with PC and debugging. RF circuit and antenna applies an RLC passive component for chip antenna to configure BALUN and antenna impedance matching circuit, allowing wireless communication. After configuring the ZigBee-chip-based communication module, tests were conducted to measure radiation level remotely: data were successfully transmitted in 10-meter and 100-meter distances, measuring radiation level in a remote condition. The communication module allows an environment where radiation level can be remotely measured in an economically beneficial way as it not only consumes less electricity but also costs less. By securing linearity of a radiation measuring device and by minimizing the device itself, it is possible to set up an environment where radiation can be measured in a reliable manner, and radiation level is monitored real-time.

• Journal of Biomedical Engineering Research
• /
• 제25권5호
• /
• pp.403-414
• /
• 2004

In the accompanying paper, we proposed a real. time volumetric imaging method using a cross array based on receive dynamic focusing and synthetic aperture focusing along lateral and elevational directions, respetively. But synthetic aperture methods using spherical waves are subject to beam spreading with increasing depth due to the wave diffraction phenomenon. Moreover, since the proposed method uses only one element for each transmission, it has a limited transmit power. To overcome these limitations, we propose a new real. time volumetric imaging method using cross arrays based on synthetic aperture technique with linear wave fronts. In the proposed method, linear wave fronts having different angles on the horizontal plane is transmitted successively from all transmit array elements. On receive, by employing the conventional dynamic focusing and synthetic aperture methods along lateral and elevational directions, respectively, ultrasound waves can be focused effectively at all imaging points. Mathematical analysis and computer simulation results show that the proposed method can provide uniform elevational resolution over a large depth of field. Especially, since the new method can construct a volume image with a limited number of transmit receive events using a full transmit aperture, it is suitable for real-time 3D imaging with high transmit power and volume rate.

• Proceedings of the Korean Vacuum Society Conference
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.425-426
• /
• 2013

IIIN계 물질 기반의 광 반도체는 직접 천이형 넓은 밴드갭 구조를 갖고 있기 때문에 적외선부터 가시광선 및 자외선까지를 포함한 폭 넓은 발광파장 조절이 가능하여 조명 및 디스플레이 관련 차세대 광원으로 많은 관심을 받고 있다. 일반적인 청색 및 녹색 발광영역의 활성층으로는 InGaN/GaN 다중양자우물구조를 사용하고 있으나, 장파장의 녹색 발광을 얻기 위해서는 인듐의 함유량이 증가하여야 한다. 하지만, 인듐의 함유량이 증가함에 따라서 InGaN/GaN 다중양자우물 구조내에서 인듐의 편석현상의 발생이 용이하게 되어 계면 특성을 저하할 뿐 아니라, 비발광 센터를 증가하여 발광 효율을 급격히 감소시키는 원인이 되고 있다. 또한, InGaN과 GaN의 큰 성장온도의 차이에 따라 800도 부근의 저온 영역에서 성장된 InGaN층이 1,000도 이상의 고온 영역에서 GaN층이 성장시 InGaN층의 열화 현상이 급격히 발생되고 있다. 이를 억제하기 위해서 금속유기화학증착법의 성장 변수 최적화, 응력제어, 도핑 등의 편석 억제기술 및 보호층이 사용되고 있다. 본 연구에서는 인듐함유량이 증가된 녹색 InGaN/GaN 다중양자우물구조에서 InGaN 우물층 상하부에 도입된 GaN 보호층에 따라 발생되는 양자우물구조의 광학 및 결정학적 특성 분석을 통해 GaN 보호층의 역할을 분석하고자 한다. 본 연구에서는 금속유기화학증착장치를 이용하여 사파이어 기판위에 GaN 템플릿을 성장하고, n-형 GaN, InGaN/GaN 다중양자우물구조 및 p-형 층을 성장하였다. 앞선 언급하였듯이, InGaN/GaN 다중양자우물구조내에 GaN 보호층의 역할을 규명하기 위하여 샘플 A의 경우는 보호층이 전혀 없는 구조이고, 샘플 B의 경우는 InGaN 우물층의 상단부에만, 샘플 C의 경우에는 우물층 상부 및 하단부 모두에 약 2.0 nm 두께의 GaN 보호층을 형성하였다. 이 보호층의 유무에 따른 다중양자우물구조의 계면 특성을 확인하기 위한 X-선 회절을 이용하였고, 광학적 특성을 확인하고 상온 포토루미네선스법을 이용하여 녹색 발광 파장의 변화 및 발광세기를 관찰하였다. 우선적으로, 상온 포토루미네선스법을 이용하여 각 샘플의 발광특성을 확인한 바 상하부 모두에 GaN 보호층이 존재하는 샘플 C의 경우 약 510 nm 부근에서 발광이 관찰되었지만, 상단부에 GaN 보호층이 존재하는 샘플 B는 약 495 nm영역에 발광이 확인되었다. 특히, 전혀 보호층이 존재하지 않는 샘플 A의 경우 약 440 nm에서 발광하는 현상을 관찰하였다. 이는 우물층 상단부 및 하단부에 존재하는 GaN 보호층이 In의 확산을 억제하는 것으로 판단된다. 또한, 발광파장 및 세기를 확인한 바, 보호층의 존재하지 않을수록 단파장화가 발생함에도 불구하고 발광세기는 급격히 약해지는 것으로 보아 계면특성이 저하되어 비발광센터가 증가되는 것으로 판단된다. 이를 구조적으로 확인하기 위하여 X-선 회절법을 통한 ${\omega}$/$2{\Theta}$ 스캔의 결과는 In의 0차 피크가 GaN 보호층이 없을 경우 GaN의 피크 방향으로 이동하는 것으로 보아 GaN 보호층은 우물층 성장 후 GaN 장벽층을 성장하기 위해 온도를 증가시키는 과정에서 In의 확산되는 것으로 판단된다. 또한, 하부 GaN 보호층의 경우 GaN 장벽층 성장 후 온도를 감소시키는 과정에서 성장되므로, 우물층으로부터 In의 탈착현상이 아닌 장벽층과의 상호 확산으로 판단된다. 또한, 계면특성을 확인하기 위해 InGaN의 X-선 위성 피크를 확인한 바 샘플 A의 경우 매우 넓고 약한 피크가 관찰된 반면, 보호층이 존재하는 샘플 B와 C의 경우 강하고 얇은 피크가 확인되었다. 이는 GaN 보호층의 도입으로 인해 계면특성이 향상되는 것으로 판단된다. 따라서, 우리는 InGaN/GaN 다중양자우물구조에서 GaN 보호층은 상부의 열화 억제 뿐아니라, 하부의 장벽층 및 우물층 사이의 상호확산을 억제하는 GaN 보호층의 도입을 통하여 우수한 계면 특성 및 비발광센터의 억제를 얻을 수 있을 것으로 생각되며, 이는 향후 GaN계 발광다이오드의 전계 발광특성을 증가하여 우수한 발광소자를 개발할 수 있을 것으로 기대된다.

• Journal of radiological science and technology
• /
• 제35권2호
• /
• pp.119-124
• /
• 2012

Recently, Glass Dosimeter (GD) with thermoluminescent Dosimeter (TLD) are comprehensively used to measure absorbed dose from diagnostic field to therapy field that means from low energy field to high energy field. However, such studies about dose characteristics of GD, such as reproducibility and energy dependency, are mostly results in high energy field. Because characteristic study for measurement devices of radiation dose and radiation detector is performed using 137Cs and 60Co which emit high energy radiations. Thus, this study was evaluated the linearity according to Piranha dose which measured by changing tube voltage (50kV, 80kV and 100kV which are low energy radiations), reproducibility and reproducibility according to delay time using GD. Measurement of radiation dose is performed using internal detector of Piranha 657 which is multi-function QA device (RTI Electronic, Sweden). Condition of measurement was 25mA, 0.02sec, 2.5mAs, SSD of 100 cm and exposure area with $10{\times}10cm^2$. As above method, GD was exposed to radiation. Sixty GDs were divided into three groups (50kV, 80kV, 100kV), then measured. In this study, GD was indicated the linearity in low energy field as high energy existing reported results. The reproducibility and reproducibility according to delay time were acceptable. In this study, we could know that GD can be used to not only measure the high energy field but also low energy field.

• Science of Emotion and Sensibility
• /
• 제23권4호
• /
• pp.105-116
• /
• 2020

The purpose of this study is to progress the limitations and disadvantages of existing safety clothing by applying high technology to current safety clothing that is produced and distributed only with fluorescent fabrics and retroreflective materials. Therefore, the industrial suspender-type safety belt and engineering technology are introduced, designed, and fabricated to help save a life in an emergency. First, the suspender-type safety belt to be developed is designed to emit light by LED attached to the film, and the body of the belt-wearer is recognized from a distance through retroreflection from the flashing LED. It aims to support people's safety by preventing accidents during roadside work, rescue activities, and sports activities at night. Second, with the development of advanced devices when the user is in an unconscious state due to distress or falls into an unconscious state due to distress or accident, the tilt sensor of the control unit attached to the belt automatically detects the angle of the human body and generates light and sound. It is intended to further enhance the utilization by mounting a sensing and signaling device that generates a distress signal and shaping it in the form of a belt attached to a vest that can be easily detached from the outside of the garment. When the wearer falls due to an accident, the tilt sensor of this belt detects the angle change and then the controller generates a high-frequency sound and repeated LED blinking signals at the same time. In the case of conventional safety vests, it is almost impossible to detect that the person is wearing a vest when there is no ambient light, but in case of the safety belts in this study, the sound and light signals of the safety belt enable us to find the wearer within 100 meters even when there is no ambient light.

• Korean Journal of Heritage: History & Science
• /
• 제54권1호
• /
• pp.260-279
• /
• 2021

The Goguryeo kingdom established a unique defense system centered on a series of mountain fortresses. However, modern-day studies on its defense system have tended to focus on how they were positioned and generally consist of little more than individual surveys or introductions to the relevant materials, leaving much to be desired. This study attempts to extend the scope of studies about fortresses dating back to the Goguryeo period, taking into account the limitations of the available materials. As such, this study reviews the defense system of Goguryeo during the Gungnaeseong Period (i.e., the period when Gungnaeseong was the capital of Goguryeo) using the GIS system, with the focus on fortresses that are thought to have been built in the area extending from the middle and upper reaches of the Amnok River to the mid-stream region of the Liohe River, based on the aforementioned studies. The results of the study are as follows. First, the major roads built during the Gungnaeseong Period were as stated in the foregoing studies to some extent. Researchers believed that during the middle period of the dynasty, a major road ran along the Suzihe, Fuer and Xinkai rivers before finally reaching Jian. The study found that fortified walls and fortress strongholds were built along this road. Second, there were seven fortresses between the middle and upper reaches of the Amnokgang River and the midstream region of the Liaohe River. A primary defense line was closely established between the strongholds and the nearby walls, with secondary and tertiary defense lines established more loosely and encompassing a much wider area. Third, regarding the defense system along the major roads, the Choejinbosanseong, Goisanseong and Cheolbaesanseong fortresses served as strongholds along the 60-kilometer-long primary defense line, with 80-kilometer-long secondary and tertiary defense lines set up behind it. The final 120-kilometer-long defense line of the capital was established along with the Onyeosanseong Fortress, while a stumbling block was set up close to the capital as a defense system, rather than building a fortified wall. To summarize, a primary defense system was established centered on a series of fortresses, with each stronghold maintaining a closely-knit defense system in connection with other nearby strongholds to repel invaders.