• Title/Summary/Keyword: science field study

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Semi-daily Variations in Populations of the Dinoflagellates Dinophysis acuminata and Oxyphysis oxytoxoides and a Mixotrophic Ciliate Prey Mesodinium rubrum in Masan Bay (마산만에서 와편모류 Dinophysis acuminata 및 Oxyphysis oxytoxoides와 먹이생물 섬모류인 Mesodinium rubrum의 단주기적 개체군 변동)

  • KIM, SUNJU;YOON, JIHAE;KIM, MIRAN;PARK, MYUNG GIL
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.20 no.3
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    • pp.151-157
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    • 2015
  • Recent laboratory studies have documented that mixotrophic dinoflagellates Dinophysis spp. and heterotrophic dinoflagellate Oxyphysis oxytoxoides share a common prey, i.e. the mixotrophic ciliate Mesodinium rubrum. Nonetheless, very little is known about the population dynamics and species interactions among these protists in natural environments. To investigate the interactions between the dinoflagellate predators and their ciliate prey in the field, we took the samples twice a day from 26 July to 28 August, 2011 at a fixed station in Masan Bay and analyzed their abundances. During this study, salinity was highly variable, ranging from 5 to 28, due to the periodic input of rainfalls to the sampling station. Water temperature was on average $26.5^{\circ}C$ until 20 August and thereafter was about $21^{\circ}C$ by the end of the sampling period. The ciliate M. rubrum occurred persistently throughout the sampling period, ranging from 13 to $492\;cells\;mL^{-1}$. Cell densities of D. acuminata and O. oxytoxoides ranged from undetectable level to $19,833\;cells\;L^{-1}$ and from undetectable level to $100,333\;cells\;L^{-1}$, respectively. The high abundance of D. acuminata mostly followed the blooming of the ciliate M. rubrum, but it often did not peak even during heavy blooms of the prey, probably due to sensitivity to large salinity fluctuation and also presumably overlapped grazing by other mixotrophic dinoflagellates. The abundance of O. oxytoxoides was detected only when water temperature was lower than $24^{\circ}C$, indicating that water temperature is an important environmental factor to control the population dynamics of the dinoflagellate species.

Performance Analysis of Implementation on IoT based Smart Wearable Mine Detection Device

  • Kim, Chi-Wook
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.12
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    • pp.51-57
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    • 2019
  • In this paper, we analyzed the performance of IoT based smart wearable mine detection device. There are various mine detection methods currently used by the military. Still, in the general field, mine detection is performed by visual detection, probe detection, detector detection, and other detection methods. The detection method by the detector is using a GPR sensor on the detector, which is possible to detect metals, but it is difficult to identify non-metals. It is hard to distinguish whether the area where the detection was performed or not. Also, there is a problem that a lot of human resources and time are wasted, and if the user does not move the sensor at a constant speed or moves too fast, it is difficult to detect landmines accurately. Therefore, we studied the smart wearable mine detection device composed of human body antenna, main microprocessor, smart glasses, body-mounted LCD monitor, wireless data transmission, belt type power supply, black box camera, which is to improve the problem of the error of mine detection using unidirectional ultrasonic sensing signal. Based on the results of this study, we will conduct an experiment to confirm the possibility of detecting underground mines based on the Internet of Things (IoT). This paper consists of an introduction, experimental environment composition, simulation analysis, and conclusion. Introduction introduces the research contents such as mines, mine detectors, and research progress. It consists of large anti-personnel mine, M16A1 fragmented anti-mine, M15 and M19 antitank mines, plastic bottles similar to mines and aluminum cans. Simulation analysis is conducted by using MATLAB to analyze the mine detection device implementation performance, generating and transmitting IoT signals, and analyzing each received signal to verify the detection performance of landmines. Then we will measure the performance through the simulation of IoT-based mine detection algorithm so that we will prove the possibility of IoT-based detection landmine.

Dipteran Comparison on Carcasses by Decomposition at Different Abandoned Site (사체의 유기장소별 부패진행에 따른 발생 파리류 비교)

  • Lim, Chae-Seak;Jo, Tae-Ho;Lee, Dong-Woon;Choo, Young-Moo;Choo, Ho-Yul
    • Korean journal of applied entomology
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    • v.51 no.3
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    • pp.191-205
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    • 2012
  • Because insect visitors was different depending on decomposition stage, dipterans occurred on chicken carcasses depending on postmortem intervals were compared by abandoned sites and decomposition from a serial study on arthropod occurrence from carcasses as forensic indicator. Species occurrence and decomposition of carcasses were different depending on abandoned sites (forest hill, open field, stream, greenhouse and roof), seasons (spring, summer, fall and winter), and situation (burying and non-burying). Development of carcass decomposition was faster at all sites in summer, carcass in greenhouse in winter, and unburied carcasses. Although visiting time of blow flies (Calliphoridae) (Phaenicia sericata, Lucilia illustris, Lucilia sp., Chrysomyia pinguis, and Chrysomyia megacephala) was different depending on abandoned season, their adults were generally collected from carcasses within 2 days. However, there were no visited flies at fresh stage of buried carcasses. The flesh flies (Sarcophagidae) were collected from all sites and seasons, and much faster from unburied carcasses than buried carcasses. Those were collected earlier from carcasses in greenhouse than other sites and occurrence was also shorter. In greenhouse, occurrence time of flesh flies were different depending on season; spring and summer - from fresh to active decay stage, fall - fresh to active decay stage, and winter - advanced decay to remains stage. Calliphora lata, Tricerotopyga calliphoroides, and Aldrichana grahami were dominant species and occurrences were different from other flies. These flies were active mainly from fresh to active stage. Larvae of sarcophagid flies were occurred earlier than those of calliphorid flies on buried carcasses.

Comparison of Lens Dose in accordance with Bismuth shielding and Patient position in Brain perfusion CT (Brain Perfusion CT에서 Bismuth 차폐와 환자의 자세 변화에 따른 수정체 선량 비교 연구)

  • Gang, Eun Bo
    • Journal of the Korean Society of Radiology
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    • v.12 no.1
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    • pp.47-52
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    • 2018
  • Brain perfusion CT scanning is often employed usefully in clinical conditions as it accurately and promptly provides information about the perfusion state of patients having acute ischemic stroke with a lot of time constraints and allows them to receive proper treatment. Despite those strengths of it, it also has a serious weakness that Lens may be exposed to a lot of dose of radiation in it. In this study, as a way to reduce the dose of radiation to Lens in brain perfusion CT scanning, this researcher conducted an experiment with Bismuth shielding and change of patients' position. TLD (TLD-100) was placed on both lens using the phantom (PBU-50), and then, in total 4 positions, parallel to IOML, parallel to IOML (Bismuth shielding), parallel to SOML, and parallel to SOML (Bismuth shielding), brain perfusion scanning was done 5 times for each position, and dose to Lens were measured. Also, to examine how the picture quality changed in different positions, 4 areas of interest were designated in 4 spots, and then, CT number and noise changes were measured and compared. According to the results of conducting one-way ANOVA on the doses measured, as the significance probability was found to be 0.000, so there was difference found in the doses of radiation to crystalline lenses. According to the results of Duncan's post-hoc test, with the scanning of being parallel to IOML as the reference, the reduction of 89.16% and 89.66% was observed in the scanning of being parallel to SOML and that of being parallel to SOML (Bismuth shielding) respectively, so the doses to Lens reduced significantly. Next, in the scanning of being parallel to IOML (Bismuth shielding), the reduction of 37.12% was found. According to the results, reduction in the doses of radiation was found the most significantly both in the scanning of being parallel to SOML and that of being parallel to SOML (Bismuth shielding). With the limit of the equivalent dose to Lens as the reference, this researcher conducted comparison with the dose to occupational exposure and dose to Public exposure in the scanning of being parallel to IOML and found 39.47% and 394.73% respectively; however in the scanning of being parallel to SOML (Bismuth shielding), considerable reduction was found as 4.08% and 40.8% respectively. According to the results of evaluation on picture quality, every image was found to meet the evaluative standards of phantom scanning in terms of the measurement of CT numbers and noise. In conclusion, it would be the most useful way to reduce the dose of radiation to Lens to use shields in brain perfusion CT scanning and adjust patients' position so that their lens will not be in the field of radiation.

Evaluation of Attenuation Rate Error on Skin Dosimeter using Monte Carlo Simulation in Photon and Electron Beam Therapy (광자선 및 전자선 치료에서 피부선량계의 측정과 시뮬레이션을 이용한 감약률 오차 평가)

  • Han, Moo-Jae;Yang, Seung-Woo;Heo, Seung-Uk;Bae, Sang-Il;Moon, Young-Min;Park, Sung-Kwang;Kim, Jin-Young
    • Journal of the Korean Society of Radiology
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    • v.14 no.6
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    • pp.841-848
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    • 2020
  • In the field of radiation therapy using photon beams and electron beams, since each patient has a different sensitivity to radiation, skin side effects may occur even at the same dose. Therefore, if there is a risk of excessive dose to the skin, a dosimeter is attached to verify whether the correct dose is being investigated. However, since the skin dosimeter checks the attachment site visually by measuring a point dose, it is difficult to confirm an accurate dose distribution. As a result, the measurement and simulation errors of the material HgI2 in the 6 MV photon beam were 3.73% and 5.24%, respectively, at the minimum thickness of 25 ㎛, and the material PbI2 was 4.73% and 5.65%, respectively. On the other hand, as a result of the 6 MeV electron beam, the measurement and simulation errors of the material HgI2 were 1.35% and 1.12%, respectively, at a minimum thickness of 25 ㎛, and the material PbI2 showed relatively low attenuation error, 1.67% and 1.20%, respectively. Therefore, it was evaluated that the thickness of the photon beam within 25 ㎛ and the electron beam within 100 ㎛ is suitable to have a reduction rate error within 5%. This study presents a new research direction for a flexible dosimeter attached to the human body that is required in clinical practice and the construction conditions of a future skin dosimeter.

Study on true nature of the Fung(風) and that of application to the medicine (풍(風)의 본질(本質)과 의학(醫學)에서의 운용(運用)에 관(關)한 고찰(考察))

  • Back, Sang Ryong;Park, Chan Kug
    • Journal of Korean Medical classics
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    • v.7
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    • pp.198-231
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    • 1994
  • Up to now, after I had examined the relation between the origin of Fung(風) and Gi(氣) and the mean of Fung in medical science, I obtained the conclusion being as follows. The first, Fung(風) means a flux of Gi(氣) and Gi shows the process by virtue of the form of Fung, namely, Fung means motion of Gi. In other words, it is flow of power. Accordingly, the process of all power can give a name Fung. The second, Samul(事物) ceaselessly interchange with the external world to sustain the existence and life of themselves. And they make a adequate confrontation against the pressure of the outside. This the motive power of life action(生命活動) is Gi and shows its the process on the strength of Fung. The third, Samul(事物) incessantly releases power which it has to the outside. Power released to the outside forms the territory of the established power in the environment of them and keep up their substance(實體) in the space time(時空). It can be name Fung because the field(場) of this power incessantly flows. The fourth, man operates life on the ground of the creation of his own vigor(生氣) for himself as the life body(生命體) of the independence and self-support. The occurence of this vigor and the adjustment process(調節作用) is supervised by Gan(肝). That is to say, Gan plays a role to regulate and manage the process of Fung or the action of vigor with Fung-Zang(風臟). The fifth, because the Gi-Gi adjustment process(氣機調節作用) of Gan is the same as the process of Fung, Fung that operates the cause of a disease is attributed to the disharmony of the process of the human body Gi-Gi. Therefore, the generating pathological change is attributed to the extraordinary of the function by the incongruity of Gi-Gi(氣機) or the disorder of the direct motion of Gi-Hyul(氣血). Because the incongruity of this Gi-Gi of the human body gives rise to the abnormal of Zung-Gi(正氣) in the human body properly cannot cope with the invasion of 'Oi-Sa(外邪). Furthermore, Fung serves as the mediation body of the invasion of other Sa-Gi(邪氣) because of its dynamics, By virtue of this reason, Fung is named the head of all disease. And because the incongruity of the Gi-Gi has each other form according to Zang-Bu(臟腑), Kyung-Lak(經絡), and a region, the symptoms of a disease appear differently in line with them as well. The sixth, Fung-byung(風病) is approximately separated Zung-Fung(中風) and Fung-byung(猍義의 風病). Zung-fung and Fung-byung is to be attributed to the major invasion of each Jung-gi and Fung-sa(正氣와 風邪). But these two kinds stir up the problem to the direct motion of Gi-hyul(氣血) and the harmony of Gi-Gi in the human body. When one cures it, therefore, Zung-fung has to rectify Gi-Gi and the circulation of Gi-hyul on the basis of the supplement of Jung-gi(正氣) and Fung-byung must make the harmony of Gi-Gi with the Gu-fung(驅風). -Go-gi(調氣), Sun-Gi(順氣). Hang-Gi(行氣) - All existing living things as well as man maintain life on the ground of the pertinent harmony between the soul(精神) and the body(肉體). As soon as the harmony falls down, simultaneously life disappears as well. And Fung which means the outside process between Gi(氣) and Gi(氣) makes the action of their life cooperative and unified, Accordingy, the understanding of Fung, first, has to start wi th the whole thought that not only all Samul(事物) but also the soul and the body are one.

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Effect of Temperature on the Quality and Storability of Cherry Tomato during Commercial Handling Condition (유통중 온도관리가 방울토마토의 품질과 저장성에 미치는 영향)

  • Islam, Mohammad Zahirul;Kim, Young-Sik;Kang, Ho-Min
    • Journal of Bio-Environment Control
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    • v.21 no.2
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    • pp.88-94
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    • 2012
  • This study was carried out in order to investigate the effect of temperature of treatment and storage on the longevity of 'Unicorn' tomatoes of light red maturity stage during commercial handling conditions encountered while exporting over long distances. Tomato stored at $5^{\circ}C$ and $11^{\circ}C$ temperature with 85% relative humidity by pre-treating handling temperature that was using from field to before shipment as a winter temperature $5^{\circ}C$, spring temperature $11^{\circ}C$ and summer temperature $25^{\circ}C$ for 3 days. On the final storage day, $25^{\circ}C/11^{\circ}C$ (treated/stored) tomatoes showed the highest respiration and ethylene production rate; whereas the lowest respiration and ethylene production rate was found for $5^{\circ}C/5^{\circ}C$ treated and stored tomatoes. Tomatoes treated and stored at $5^{\circ}C/5^{\circ}C$ showed higher marketability, without evidence of fungal rot, decay or spots for 23 days. The fresh weight loss under all treatment conditions increased gradually during $5^{\circ}C$ and $11^{\circ}C$ storage temperatures. The higher firmness and soluble solids were determined from $5^{\circ}C/5^{\circ}C$ and $5^{\circ}C/11^{\circ}C$ treated and stored tomatoes repectively, than from others tomatoes on the final day of storage. In addition, $5^{\circ}C/5^{\circ}C$ tomatoes showed higher vitamin C contents than tomatoes stored at other temperatures, on the final day of storage. As the ripening and storage period progressed, the titratable acidity increased, but declined (P < 0.05) thereafter, due to over ripe tomatoes under all treatment conditions. These results show that $5^{\circ}C/5^{\circ}C$ treated and stored light red maturity stages of 'Unicorn' tomatoes are optimum to export because they show the highest storability and marketability. Moreover, the marketability of light red maturity stage of 'Unicorn' tomato maintained for 2 weeks in $25^{\circ}C/11^{\circ}C$ treated and stored temperature that might be the export temperature from Korea to Japan in summer season. This research result could be useful in helping tomato growers and exporters to get optimum market value by satisfying the buyer and consumer with a fresher product.

A Study on the RFID's Application Environment and Application Measure for Security (RFID의 보안업무 적용환경과 적용방안에 관한 연구)

  • Chung, Tae-Hwang
    • Korean Security Journal
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    • no.21
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    • pp.155-175
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    • 2009
  • RFID that provide automatic identification by reading a tag attached to material through radio frequency without direct touch has some specification, such as rapid identification, long distance identification and penetration, so it is being used for distribution, transportation and safety by using the frequency of 125KHz, 134KHz, 13.56MHz, 433.92MHz, 900MHz, and 2.45GHz. Also it is one of main part of Ubiquitous that means connecting to net-work any time and any place they want. RFID is expected to be new growth industry worldwide, so Korean government think it as prospective field and promote research project and exhibition business program to linked with industry effectively. RFID could be used for access control of person and vehicle according to section and for personal certify with password. RFID can provide more confident security than magnetic card, so it could be used to prevent forgery of register card, passport and the others. Active RFID could be used for protecting operation service using it's long distance date transmission by application with positioning system. And RFID's identification and tracking function can provide effective visitor management through visitor's register, personal identification, position check and can control visitor's movement in the secure area without their approval. Also RFID can make possible of the efficient management and prevention of loss of carrying equipments and others. RFID could be applied to copying machine to manager and control it's user, copying quantity and It could provide some function such as observation of copy content, access control of user. RFID tag adhered to small storage device prevent carrying out of item using the position tracking function and control carrying-in and carrying-out of material efficiently. magnetic card and smart card have been doing good job in identification and control of person, but RFID can do above functions. RFID is very useful device but we should consider the prevention of privacy during its application.

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The Egg Development of Korean Slender Gudgeon, Squalidus gracilis majimae (Cypriniforms: Cyprinidae) (한국산 긴몰개 (Squalidus gracilis majime, Cyprinidae)의 난발생)

  • Park, Kyung-Seo;Hong, Young-Pyo;Moon, Woon-Ki;Choi, Shin-Suk;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.38 no.1 s.110
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    • pp.73-82
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    • 2005
  • This study was conducted, based on the field survey and laboratory observations, to elucidate egg developmental processes and their characteristics of the Korean slender gudgeon, Squalidus gracilis majimae. For the experiments, the mature adults were collected at the Woongcheon-Cheon Stream and Boreung Reservoir located in Boreung City, Chungnam Province and eggs were obtained from the natural spawning area. Morphological characteristics of the egg and embryonic development were summarized as follows: The shape of the fertilized egg was spherical, adhesive and transparent. The fertilized egg was 2.9${\pm}$0.3 mm (n = 30) in mean diameter under water temperature of $26{\pm}1.5^{\circ}C$, light white in color and had no oil droplets. After 20 minutes from the time of fertilization, a blastodisc was formed and divided into two cells at 48 minutes after fertilization. The blastular stage occurred at 5 hours 40 minutes after fertilization and the gastrular stage was detected at 8 hours 41 minutes after fertilization. The beginning of embryo formation was observed at 12 hours 58 minutes after fertilization and optic vesicles and 9 somites were discovered at 17 hours 05 minutes after fertilization. Differentiation of brains and embryo wiggling were observed at 37 hours 27 minutes after fertilization. Heart beating and the formation of melanophores in optic vesicles were detected at 44 hours 46 minutes after fertilization. The formation of pectoral fins and melanophores in the body were discovered at 50 hours 36 minutes after fertilization. Hatching occurred at 57 hours 49 minutes after fertilization. The newly hatched larvae were 3.3${\pm}$0.2 mm (n = 120) in total length. We believe that these results may contribute the species and population conservations under the situation of accelerated water pollution and the decreases of its diversity.

Dynamics of Phosphorus-Turbid Water Outflow and Limno-Hydrological Effects on Hypolimnetic Effluents Discharging by Hydropower Electric Generation in a Large Dam Reservoir (Daecheong), Korea (대청호 발전방류수의 인·탁수 배출 역동성과 육수·수문학적 영향)

  • Shin, Jae-Ki;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.50 no.1
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    • pp.1-15
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    • 2017
  • Daecheong Reservoir was made by the construction of a large dam (>15 m in height) on the middle to downstream of the Geum River and the discharge systems have the watergate-spillway (WS), a hydropower penstock (HPP), and two intake towers. The purpose of this study was to investigate the limnological anomalies of turbid water reduction, green algae phenomenon, and oligotrophic state in the lower part of reservoir dam site, and compared with hydro-meteorological factors. Field surveys were conducted in two stations of near dam and the outlet of HPP with one week intervals from January to December 2000. Rainfall was closely related to the fluctuations of inflow, outflow and water level. The rainfall pattern was depended on the storm of monsoon and typhoon, and the increase of discharge and turbidity responded more strongly to the intensity than the frequency. Water temperature and DO fluctuations within the reservoir water layer were influenced by meteorological and hydrological events, and these were mainly caused by water level fluctuation based on temperature stratification, density current and discharge types. The discharges of WS and HPP induced to the flow of water bodies and the outflows of turbid water and nutrients such as nitrogen and phosphorus, respectively. Especially, when hypoxic or low-oxygen condition was present in the bottom water, the discharge through HPP has contributed significantly to the outflow of phosphorus released from the sediment into the downstream of dam. In addition, HPP effluent which be continuously operated throughout the year, was the main factor that could change to a low trophic level in the downreservoir (lacustrine zone). And water-bloom (green-tide) occurring in the lower part of reservoir was the result that the water body of upreservoir being transported and diffused toward the downreseroir, when discharging through the WS. Finally, the hydropower effluent was included the importance and dynamics that could have a temporal and spatial impacts on the physical, chemical and biological factors of the reservoir ecosystem.