• Title/Summary/Keyword: Gamma Detection

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Observation of Several Detection Factors Derived from Thermoluminescence of Mineral Separated from Irradiated Korean Sesame and Perilla Seeds Stored under Different Storage Conditions

  • Oh, Man-Jin;Yi, Sang-Duk;Yang, Jae-Seung
    • Preventive Nutrition and Food Science
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    • v.7 no.2
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    • pp.188-194
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    • 2002
  • This study was carried out to observe changes in several detection factors derived from thermoluminescence (TL) of minerals separated from irradiated Korean perilla and sesame seeds during storage under normal room and darkroom conditions. The TL intensities of the first glow curves increased from 0 to 5 kGy but only slightly increase from 5 to 10 kGy. Maximum TL temperatures of the first glow curves in all irradiated samples were around 20$0^{\circ}C$, ranging from 150 to 25$0^{\circ}C$. Since the control (0 day of storage) glow curve ratios of G3 and G4, calculated from re-irradiated (1 kGy) sample were over 0.5, detection of irradiation was possible. However, because Gl ratios were below 0.1, they were classified as non-irradiated. There was n unique first glow curve shape that could be clearly seen in all irradiated samples, regardless of storage conditions, that was never seen in non-irradiated samples. In all samples, the maximum TL temperatures and shape of the second glow curve was in a lower temperature range than that of the first glow curve. Therefore, detection of irradiated Korean perilla and sesame seeds was possible fur up to 3 months after irradiation, regardless of storage conditions, by examining several TL detection factors; including TL intensity, glow curve ratios maximum TL temperatures, and the shapes of glow curves.

Unlimited Cooperative Sensing with Energy Detection for Cognitive Radio

  • Bae, Sunghwan;Kim, Hongseok
    • Journal of Communications and Networks
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    • v.16 no.2
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    • pp.172-182
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    • 2014
  • In this paper, we investigate the fundamental performance limits of the cooperative sensing using energy detection by considering the unlimited number of sensing nodes. Although a lot of cognitive radio research so far proposed various uses of energy detection because of its simplicity, the performance limits of energy detection have not been studied when a large number of sensing nodes exist. First, we show that when the sensing nodes see the independent and identically distributed channel conditions, then as the number of sensing nodes N goes to infinity, the OR rule of hard decision achieves zero of false alarm Pf for any given target probability of detection $\bar{P_d}$ irrespective of the non-zero received primary user signal to noise ratio ${\gamma}$. Second, we show that under the same condition, when the AND rule of hard decision is used, there exists a lower bound of $P_f$. Interestingly, however, for given $\bar{P_d}$, $P_f$ goes to 1 as N goes to infinity. Third, we show that when the soft decision is used, there exists a way of achieving 100% utilization of secondary user, i.e., the sensing time overhead ratio goes to zero so does $P_f$.We verify our analyses by performing extensive simulations of the proposed unlimited cooperative sensing. Finally, we suggest a way of incorporating the unlimited cooperative sensing into a practical cellular system such as long term evolutionadvanced by exploiting the existing frame structure of absolute blank subframe to implement the in-band sensing.

Detection Capability by Change of Amylograph Characteristics of Irradiated Black Pepper (방사선 조사된 검은후추가루의 Amylograph Characteristics의 변화에 따른 검지 가능성)

  • Yi, Sang-Duk;Oh, Man-Jin;Yang, Jae-Seung
    • Korean Journal of Food Science and Technology
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    • v.33 no.2
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    • pp.195-199
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    • 2001
  • A study was carried out to establish a detection method for irradiated black pepper using amylograph characteristics. The maximum viscosity, viscosity at $93^{\circ}C$, viscosity after 15 min at $93^{\circ}C$, viscosity at $45^{\circ}C$, viscosity after 30 min at $45^{\circ}C$, and viscosity after 60 min at $45^{\circ}C$ decreased with increasing irradiation doses, but initial pasting temperatures, maximum viscosity temperatures, breakdown, setback, and consistency did not show great changes. The high correlation coefficients $(R^2>0.97)$ were shown between irradiation doses and amylograph characteristics except for breakdown $(R^2>0.75)$, setback $(R^2>0.88)$ and consistency $(R^2>0.31)$. These results suggest that detection of irradiated black pepper is possible using amylograph characteristics.

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Detection of Flaws in Air Deck using Non-Destructive Testing (비파괴 검사를 이용한 항공 갑판의 결함 검출)

  • Kim, Kwang-Baek;Cho, Jae-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.9
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    • pp.1865-1870
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    • 2011
  • In this paper, we propose an effective method that automatically detects flaws in air deck by using non-destructive testing. First, Gamma correlation transform, 7 ${\times}$ 7 and 13 ${\times}$ 13 Sobel mask apply to the image of air deck acquired non-destructive testing in order to detect the edge of the image. Second, the edge detection area is smoothed and corrected by mean binarization method. Finally, the region of flaws in air deck is detected by a labeling method after removing the noise by the erosion and the dilation operation. In experimental results, we showed that the proposed detection method is effective in air deck.

A Study on the Motion Object Detection Method for Autonomous Driving (자율주행을 위한 동적 객체 인식 방법에 관한 연구)

  • Park, Seung-Jun;Park, Sang-Bae;Kim, Jung-Ha
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.5
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    • pp.547-553
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    • 2021
  • Dynamic object recognition is an important task for autonomous vehicles. Since dynamic objects exhibit a higher collision risk than static objects, our own trajectories should be planned to match the future state of moving elements in the scene. Time information such as optical flow can be used to recognize movement. Existing optical flow calculations are based only on camera sensors and are prone to misunderstanding in low light conditions. In this regard, to improve recognition performance in low-light environments, we applied a normalization filter and a correction function for Gamma Value to the input images. The low light quality improvement algorithm can be applied to confirm the more accurate detection of Object's Bounding Box for the vehicle. It was confirmed that there is an important in object recognition through image prepocessing and deep learning using YOLO.

Anomaly Detection and Diagnostics (ADD) Based on Support Vector Data Description (SVDD) for Energy Consumption in Commercial Building (SVDD를 활용한 상업용 건물에너지 소비패턴의 이상현상 감지)

  • Chae, Young-Tae
    • Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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    • v.12 no.6
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    • pp.579-590
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    • 2018
  • Anomaly detection on building energy consumption has been regarded as an effective tool to reduce energy saving on building operation and maintenance. However, it requires energy model and FDD expert for quantitative model approach or large amount of training data for qualitative/history data approach. Both method needs additional time and labors. This study propose a machine learning and data science approach to define faulty conditions on hourly building energy consumption with reducing data amount and input requirement. It suggests an application of Support Vector Data Description (SVDD) method on training normal condition of hourly building energy consumption incorporated with hourly outdoor air temperature and time integer in a week, 168 data points and identifying hourly abnormal condition in the next day. The result shows the developed model has a better performance when the ${\nu}$ (probability of error in the training set) is 0.05 and ${\gamma}$ (radius of hyper plane) 0.2. The model accuracy to identify anomaly operation ranges from 70% (10% increase anomaly) to 95% (20% decrease anomaly) for daily total (24 hours) and from 80% (10% decrease anomaly) to 10%(15% increase anomaly) for occupied hours, respectively.

Brain Metastases from Well-Differentiated Thyroid Carcinoma (뇌 전이 분화 갑상선암)

  • Lee Jan-Dee;Yoon Jong-Ho;Chang Hang-Seok;Park Cheong-Soo
    • Korean Journal of Head & Neck Oncology
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    • v.20 no.1
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    • pp.7-12
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    • 2004
  • Background and Objectives: Brain metastasis from well-differentiated thyroid carcinoma is uncommon, and the treatment remains controversial. In this study, we analyzed cases of brain metastasis from well differentiated thyroid carcinoma to determine optimal treatment. Material and Methods: From March 1986 to May 2003, we experienced 13 cases of brain metastases from well-differentiated thyroid carcinomas. There were 6 men and 7 women with a mean age of 62.3 years. The time interval detecting the brain metastasis, treatment methods, outcomes, and the prognostic factors were analyzed. Results: In 11 patients, brain metastasis was found at a mean of 96 months after thyroid surgery (range, 1-204months). In 1 patient, brain metastasis was found simultaneously with the thyroid cancer. In the remaining one, brain metastasis was presented as the first sign. Treatment included gamma knife therapy in 2, external radiation therapy (ExRT) in 2, resection and ExRT in 2, gamma knife therapy and ExRT in 2 and intracranial holmium injection in 1. Three patients received no treatment. The mean survival was 20.5months (1-119 months). Only 2 patients with early detection remained alive after treatment (23months and 119months). The age, sex, primary tumor size, combined organs of distant metastasis and treatment methods did not affect the prognosis. There were noticeable symptomatic improvements in patients who received any kind of treatment for brain metastasis. Conclusion: Early detection and treatment of brain metastasis appears to bring symptomatic relief and improve survival. Therefore, early screening for brain metastasis is recommended for patients with symptoms. However, further study is needed to determine the optimal method of treatment.

Germination properties of Wheat and Barley Exposed to Gamma Irradiation (감마선 조사된 밀과 보리의 검지를 위한 발아특성 비교)

  • 오경남;김경은;양재승
    • Journal of Food Hygiene and Safety
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    • v.16 no.2
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    • pp.139-144
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    • 2001
  • A 5-day germination test is applicable to detect biological changes in irradiated wheat and barley at low doses. Seeds were irradiated at below 0.5 kGy, husked and placed on distilled water-moistend filter paper in a covered Petri-dish. Water was supplied everyday. To evaluate the growth rate, the length of shoots and roots was measured during germination. In wheat, the shoots of all samples grew well during 5 days, but the shoot length and the daily growth extent decreased with increasing doses. The roots of non-irradiated wheat showed the highest daily growth extent during 5 days and the root length was over 20 mm at 3rd day. In barley, the growth of shoots and roots was retarded at 0.3 kGy or more after 3 days. It was concluded that if the root length was 20mm or longer within 3 days, wheat and barley were identified as non-irradiated. The germination test was proved a promising screening method for the detection of irradiated wheal and barley.

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Properties of Pulsed Photostimulated Luminescence and Thermoluminescence for Detection of Gamma-Irradiated Teas during Storage

  • Kausar, Tusneem;Kim, Byeong-Keun;Yang, Jae-Seung;Byun, Myung-Woo;Kwon, Joong-Ho
    • Preventive Nutrition and Food Science
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    • v.9 no.3
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    • pp.227-231
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    • 2004
  • Green, black and oolong teas were irradiated by $^{60}$ Co-gamma rays (0~10 kGy) and were investigated for detection of irradiation treatment using pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL) during storage. Teas irradiated at 2.5 kGy or more showed a photon count of greater than 5000 counts/60 sec while the non-irradiated yielded only 650~1000 count/60 sec. Correlation coefficients between irradiation dose and photon counts/60 sec were 0.8951, 0.7934 and 0.9007 for green, black and oolong teas, respectively. The TL glow curves for minerals isolated from the non-irradiated teas were situated at about 30$0^{\circ}C$ with a low intensity, but for irradiated samples were approximately 15$0^{\circ}C$ with a high intensity. The TL ratios (TL$_1$/TL$_2$), calculated from values after initial radiation and then after re-irradiation of the teas, were below 0.1 for the non-irradiated samples and higher than 1.44 for all irradiated samples, enhanced the reliability of the identification results for TL. The signal intensity of PPSL and TL for irradiated teas decreased with the lapse of post-irradiation storage time at room temperature but was still distinguishable from that of the non-irradiated samples even after one year.

Applications of Ship Domain Theory to Identify Risky Sector in VTS Area

  • Gang, Sang-Guen;Jeong, Jae-Yong;Yim, Jeong-Bin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.3
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    • pp.277-284
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    • 2014
  • This paper describes the application method of bumper area defined in the ship domain theory and it is to identify risky sectors in VTS(Vessel Traffic Services) area. The final goal of this work is to develop early warning system providing the location information with high traffic risks in Mokpo VTS area and to prevent the human errors of VTS Officer(VTSO). The current goal of this paper is to find evaluation and detection method of risky sectors. The ratio between overlapped bumper area of each vessels and the summing area of a designated sector, Ratio to Evaluate Risk(RER) ${\gamma}$ is used as one of evaluation and detection parameter. The usability of overlapped bumper area is testified through three kinds of scenarios for various traffic situations. The marine traffic data used in the experiments is collected by AIS(Automatic Identification System) receiver and then compiled in the SQL(Structured Query Language) Server. Through the analysis of passing vessel's tracks within the boundary of Mokpo VTS area, the total of 11 sectors are identified as evaluation unit sector. As experiment results from risk evaluation for the 11 sectors, it is clearly known that the proposed method with RER ${\gamma}$ can provide the location information of high risky sectors which are need to keep traffic tracks of vessel movements and to maintain traffic monitoring by VTSO.