• Title/Summary/Keyword: Dead-Time

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Gallic acid caused cultured mice TM4 Sertoli cells apoptosis and necrosis

  • Li, Wanhong;Yue, Xiangpeng;Li, Fadi
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.5
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    • pp.629-636
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    • 2019
  • Objective: The study was designed to determine the cytotoxic effect of gallic acid (GA), obtained by the hydrolysis of tannins, on mice TM4 Sertoli cells apoptosis. Methods: In the present study, non-tumorigenic mice TM4 Sertoli cells were treated with different concentrations of GA for 24 h. After treatment, cell viability was evaluated using WST-1, mitochondrial dysfunction, cells apoptosis and necrosis was detected using JC-1, Hoechst 33342 and propidium iodide staining. The expression levels of Cyclin B1, proliferating cell nuclear antigen (PCNA), Bcl-2-associated X protein (BAX), and Caspase-3 were also detected by quantitative real-time polymerase chain reaction and Western-blotting. Results: The results showed that 20 to $400{\mu}M$ GA inhibited viability of TM4 Sertoli cells in a dose-dependent manner. Treatment with $400{\mu}M$ GA significantly inhibited PCNA and Cyclin B1 expression, however up-regulated BAX and Caspase-3 expression, caused mitochondrial membrane depolarization, activated Caspase-3, and induced DNA damage, thus, markedly increased the numbers of dead cells. Conclusion: Our findings showed that GA could disrupt mitochondrial function and caused TM4 cells to undergo apoptosis and necrosis.

Optimal Two Degrees-of-Freedom Based Neutral Point Potential Control for Three-Level Neutral Point Clamped Converters

  • Guan, Bo;Doki, Shinji
    • Journal of Power Electronics
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    • v.19 no.1
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    • pp.119-133
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    • 2019
  • Although the dual modulation wave method can solve the low-frequency neutral point potential (NPP) fluctuation problem for three-level neutral point clamped converters, it also increases the switching frequency and limits the zero-sequence voltage. That makes it harmful when dealing with the NPP drift problem if the converter suffers from a long dead time or asymmetric loads. By introducing two degrees of freedom (2-DOF), an NPP control based on a search optimization method can demonstrate its ability to cope with the above mentioned two types of NPP problems. However, the amount of calculations for obtaining an optimal 2-DOF is so large that the method cannot be applied to certain industrial applications with an inexpensive digital signal processor. In this paper, a novel optimal 2-DOF-based NPP control is proposed. The relationships between the NPP and the 2-DOF are analyzed and a method for directly determining the optimal 2-DOF is also discussed. Using a direct calculation method, the amount of calculations is significantly reduced. In addition, the proposed method is able to maintain the strongest control ability for the two types of NPP problems. Finally, some experimental results are given to confirm the validity and feasibility of the proposed method.

Measuring gameplay similarity between human and reinforcement learning artificial intelligence (사람과 강화학습 인공지능의 게임플레이 유사도 측정)

  • Heo, Min-Gu;Park, Chang-Hoon
    • Journal of Korea Game Society
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    • v.20 no.6
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    • pp.63-74
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    • 2020
  • Recently, research on automating game tests using artificial intelligence agents instead of humans is attracting attention. This paper aims to collect play data from human and artificial intelligence and analyze their similarity as a preliminary study for game balancing automation. At this time, constraints were added at the learning stage in order to create artificial intelligence that can play similar to humans. Play datas obtained 14 people and 60 artificial intelligence by playing Flippy bird games 10 times each. The collected datas compared and analyzed for movement trajectory, action position, and dead position using the cosine similarity method. As a result of the analysis, an artificial intelligence agent with a similarity of 0.9 or more with humans was found.

Systemic Amyloidosis in an African Penguin (Spheniscus Demersus) with Bumblefoot

  • Kim, Nak-Hyoung;Park, Ji-Hyung;Hong, Won-Hee;Jung, Ji-Youl;Kim, Jae-Hoon
    • Journal of Veterinary Clinics
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    • v.39 no.2
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    • pp.81-86
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    • 2022
  • A female, 14-year-old, African penguin (Spheniscus demersus) weighing 2.5 kg with the anorexia for one day and 22 months history of bumblefoot was found dead in aquarium. Grossly, severe bumblefoot in the central surface of the right foot, severe enlarged liver and kidneys with orange color were observed. Histopathologically, pinkish amorphous materials were accumulated in liver, spleen, kidney, and stomach. The pinkish materials in the liver, kidney, spleen, and stomach were confirmed as amyloid with typical orange color reactions using Congo red stain under the light microscope and with bright red color expressions using Congo red stain under the fluorescence microscope. Based on the typical gross and histopathologic findings and special staining, this case was confirmed as systemic amyloidosis. A long period time of moderate bumblefoot might be closely associated with the occurrence of systemic amyloidosis in the captive penguin.

The effect of front edge on efficiency for point and volume source geometries in p-type HPGe detectors

  • Esra Uyar ;Mustafa Hicabi Bolukdemir
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4220-4225
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    • 2022
  • Monte Carlo (MC) simulations are increasingly being used as an alternative or supplement to the gamma spectrometric method in determining the full energy peak efficiency (FEPE) necessary for radionuclide identification and quantification. The MC method is more advantageous than the experimental method in terms of both cost and time. Experimental calibration with standard sources is difficult, especially for specimens with unusually shaped geometries. However, with MC, efficiency values can be obtained by modeling the geometry as desired without using any calibration source. Modeling the detector with the correct parameters is critical in the MC method. These parameters given to the user by the manufacturer are especially the dimensions of the crystal and its front edge, the thickness of the dead layer, dimensions, and materials of the detector components. This study aimed to investigate the effect of the front edge geometry of the detector crystal on efficiency, so the effect of rounded and sharp modeled front edges on the FEPE was investigated for <300 keV with three different HPGe detectors in point and volume source geometries using PHITS MC code. All results showed that the crystal should be modeled as a rounded edge, especially for gamma-ray energies below 100 keV.

A History of Geomorphological Researches on Baekdusan Volcano (백두산 화산지형에 관한 연구사)

  • Park, Kyeong
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.3
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    • pp.75-85
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    • 2020
  • Few studies have dealt with the question of when Mt. Baekdusan became known as a volcano. Attention has been focused rather on the issue of establishing the boundary between the Joseon Dynasty and the Qing Dynasty than the scientific nature of Baekdusan as a volcano. It is only in the late Joseon Dynasty that Park Jong (1764), who was the scholar of the Gwanbuk region, authored the first travel journal on Mt. Baekdu and described poseok. Due to the scientific curiosity of Westerners on the existence of mysterious snow peak on the border, it was first introduced to the Royal Geographical Society by a British man, H.E.M. James in 1887, who revealed for the first time that Mt. Baekdu is a dead volcano, and that the white color on the top is due to wide-spread pumice. Russian expedition teams including Strel'bitskii (Стрельбицкий, 1894, and Garin (Гарин-Михайловский, 1898), also explored this mountain seeking natural resources and territory of East Asia and the Manchurian region in pursuit of Russian Imperial interests explored and described Baekdusan as a volcano.

Marina Carr's By the Bog of Cats... : Hester's Becoming-Ghost (마리나 카의 『고양이 늪』 -헤스터의 유령-되기)

  • Chung, Moonyoung
    • Journal of English Language & Literature
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    • v.58 no.1
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    • pp.69-91
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    • 2012
  • Marina Carr's By the Bog of Cats.... (1998) is the last play of the trilogy of "the midlands plays" which can be regarded as her re-writing of both Euripides' Medea and J. M. Synge's The Playboy of the Western World by resetting the two plays in the midlands of contemporary Ireland. Carr intends to courageously explore into the dangerous liminal space, i.e., the middle between the past and the present, the high Greek and the Irish folk culture, dealing with the ghosts of the dead writers for her own Irish feminist theatre. Thus, in the middle Carr can build a new Irish theatre by minorating and abjecting the Greek tragedy and subverting and expanding Synge's theatre of grotesque realism. This paper attempts to read By the Bog of Cats... as Carr's final project of exploration into the midland of Ireland to establish a new Irish feminist theatre and at the same time a new Irish folk theatre. By focusing on her strategies of minoration and subversion through grotesque imagery and carnival rituals it argues that Carr put Hester's becoming-ghost in the middle, the bog of the cats as both grave and womb, waiting for the birth of a new Irish people. And it emphasizes that the ghost of Hester, merging with the ghosts of her mother and daughter by the bog of cats will haunt the official society as a threatening abjection, challenging the restoration of the social order.

The Evaluation of Usefulness of Pixelated Breast-Specific Gamma Imaging in Thyroid scan (Pixelated Breast-Specific Gamma Imaging(BSGI) 감마 카메라를 이용한 갑상선 검사의 유용성 평가)

  • Jung, Eun-Mi;Seong, Ji-Hye;Yoo, Hee-Jae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.1
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    • pp.90-93
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    • 2011
  • Purpose: A Pixelated BSGI gamma camera has features to enhance resolution and sensitivity and minimize the distance between detector and organs by narrow FOV. Therefore, it is known as useful device to examine small organs such as thyroid, parathyroid and gall bladder. In general, when we would like to enlarge the size of images and obtain high resolution images by gamma camera in nuclear medicine study, we use pinhole collimator. The purpose of this study is to evaluate the usefulness of Pixelated BSGI gamma camera and to compare to it using pinhole collimator in thyroid scan which is a study of typical small organs. Materials and methods: (1) The evaluation of sensitivity and spatial resolution: We measured sensitivity and spatial resolution of Pixelated BSGI with LEHR collimator and Infinia gamma camera with pinhole collimator. The sensitivity was measured by point source sensitivity test recommended by IAEA. We acquired images considering dead time in BSGI gamma camera for 100 seconds and used $^{99m}TcO4-\;400{\mu}Ci$ line source. (2) The evaluation of thyroid phantom: The thyroid phantom was filled with $^{99m}TcO4-$. After set 300 sec or 100 kcts stop conditions, we acquired images from both pixelated BSGI gamma camera and Infinia gamma camera with LEHR collimator. And we performed all thyroid studies in the same way as current AMC's procedure. Results: (1) the result of sensitivity: As a result, the sensitivity and spatial resolution of pixelated BSGI gamma camera were better than Infinia's. The sensitivities of pixelated BSGI and Infinia gamma camera were $290cps/{\mu}Ci$ and $350cps/{\mu}Ci$ respectively. So, the sensitivity of pixelated BSGI was 1.2 times higher than Infinia's (2) the result of thyroid phantom: Consequently, we confirmed that images of Pixelated BSGI gamma camera were more distinguishable between hot and cold spot compared with Infinia gamma camera. Conclusion: A pixelated BSGI gamma camera is able to shorten the acquisition time. Furthermore, the patients are exposed to radiation less than before by reducing amount of radiopharmaceutical doses. Shortening scan time makes images better by minimizing patient's breath and motion. And also, the distance between organ and detector is minimized because detector of pixelated BSGI gamma camera is small and possible to rotate. When patient cannot move at all, it is useful since device is feasible to move itself. However, although a pixelated BSGI gamma camera has these advantages, the effect of dead time occurs over 2000 cts/s since it was produced only for breast scan. So, there were low concentrations in organ. Therefore, we should consider that it needs to take tests to adjust acquisition time and amount of radiopharmaceutical doses in thyroid scan case with a pixelated BSGI gamma camera.

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Effect of Feed Withdrawal Time on Quality of Broiler Meat (절식시간이 닭고기 품질에 미치는 영향)

  • Choi, Jung Suck;Park, Ki Soo;Lee, Jae Ik;Auh, Joong Hyuck;Choi, Yang Il
    • Journal of Animal Science and Technology
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    • v.50 no.3
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    • pp.373-380
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    • 2008
  • This study was undertaken to investigate the effects of feed withdrawal time(FWT) before transport in farm(<2 hrs, 2~4 hrs, 4~6 hrs) and total feed withdrawal time(TFWT) before slaughter(<8 hrs, 8~12 hrs, >12 hrs) on carcass defects, grades and meat quality of broilers. FWT of 2~4 hrs before transport in the farm showed lower incidences of dead-on-arrival chicks(p<0.05) and bruising chicks, and a little higher incidences of 1st or 2nd carcass grade compared to shorter than 2 hrs or 4~6 hrs of FWT in the farm. In the meat quality of breast meat, FWT of 2~4 hrs in the farm tended to show higher pH and water holding capacity(WHC), and lower drip loss, cooking loss and shear force values compared to shorter than 2 hrs or 4~6 hrs of FWT in the farm. In the total microbial counts of breast meat during 7 days of cooler storage, FWT of 2~4 hrs in the farm showed significantly lower value than shorter than 2 hrs of FWT in the farm. In the carcass defects and grades by TFWT before slaughter, TFWT shorter than 8hrs showed lower(p<0.05) incidences of dead-on-arrival chicks and bruising chicks, and higher(p<0.05) incidences of 1st carcass grade than TFWT longer than 12 hrs before slaughter. In the meat quality of broiler breast meat, TFWT longer than 12hrs before slaughter showed lower(p<0.05) pH and WHC values, and a little higher drip loss, cooking loss and shear force values compared to TFWT shorter than 8 hrs or 8~12 hrs before slaughter. In the total microbial counts of broiler breast meat during 7 days of cooler storage, TFWT longer than 12 hrs before slaughter tended to show higher value than TFWT shorter than 8 hrs or 8~12 hrs before slaughter. As a result, 2~4 hrs of feed withdrawal time before transport in the farm and total feed withdrawal time shorter than 8hrs or 8~12hrs before slaughter could be recommended for the production of high quality broiler meat.

The Effectiveness of Progressive Tension Suture at Latissimus Dorsi Muscle Harvest (광배근 근피판 거상 후 점진적 긴장 봉합술의 유용성)

  • Moon, Joo Bong;Park, Jung Min;Kwon, Yong Seok;Lee, Keun Cheol;Kim, Seok Kwun;Cho, Se Heon
    • Archives of Plastic Surgery
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    • v.34 no.5
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    • pp.611-616
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    • 2007
  • Purpose: The latissimus dorsi muscle flap is a versatile flap used in a variety of reconstructive procedures. The most common complication of LD muscle flap is donor site seroma, reported to occur in 20 to 79 percent of cases. The formation of dead space under the flap is intimately associated with seroma formation. The authors think that the use of progressive tension suture at closing donor site can decrease the formation of dead space and ultimately reduce the incidence of donor site seroma. Methods: A retrospective review was performed with 38 patients who underwent latissimus dorsi muscle harvest for breast reconstruction from March 2003 to September 2004. Progressive tension sutures were used during donor site closure in 22 patients. This group was compared with controls group(16 patients) who underwent latissimus dorsi muscle harvest without using this technique. Operation time, length of hospital stay, period of drainage, complication, and satisfaction about postoperative scar of donor site were examined. Results: The average length of hospital stay was 10.2 days and 12.7 days, and the mean duration of drainage were 7.3 days and 11.7 days in each progressive suture group and control group. These results were statistically significant (p<0.05). In the 22 patients who underwent progressive tension suture, none had seroma, hematoma or skin necrosis. In control group(16 patients), there happened one seroma formation and one partial skin necrosis. These complications were healed by aspiration of seroma and wound revision. The patients' satisfaction was not statistically significant, but the higher points were given by the patients who underwent progressive tension suture. Conclusion: This technique, progressive tension suture, is an effective method to reduce or eliminate donor site seroma, which is the most common complication associated with latissimus dorsi muscle harvest.