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Real-Time Scheduling Scheme based on Reinforcement Learning Considering Minimizing Setup Cost (작업 준비비용 최소화를 고려한 강화학습 기반의 실시간 일정계획 수립기법)

  • Yoo, Woosik;Kim, Sungjae;Kim, Kwanho
    • The Journal of Society for e-Business Studies
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    • v.25 no.2
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    • pp.15-27
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    • 2020
  • This study starts with the idea that the process of creating a Gantt Chart for schedule planning is similar to Tetris game with only a straight line. In Tetris games, the X axis is M machines and the Y axis is time. It is assumed that all types of orders can be worked without separation in all machines, but if the types of orders are different, setup cost will be incurred without delay. In this study, the game described above was named Gantris and the game environment was implemented. The AI-scheduling table through in-depth reinforcement learning compares the real-time scheduling table with the human-made game schedule. In the comparative study, the learning environment was studied in single order list learning environment and random order list learning environment. The two systems to be compared in this study are four machines (Machine)-two types of system (4M2T) and ten machines-six types of system (10M6T). As a performance indicator of the generated schedule, a weighted sum of setup cost, makespan and idle time in processing 100 orders were scheduled. As a result of the comparative study, in 4M2T system, regardless of the learning environment, the learned system generated schedule plan with better performance index than the experimenter. In the case of 10M6T system, the AI system generated a schedule of better performance indicators than the experimenter in a single learning environment, but showed a bad performance index than the experimenter in random learning environment. However, in comparing the number of job changes, the learning system showed better results than those of the 4M2T and 10M6T, showing excellent scheduling performance.

The Effect of PET Scan Time on the Off-Line PET Image Quality in Proton Therapy (양성자 치료에서 영상 획득 시간에 따른 Off Line PET의 효율성 검증)

  • Hong, Gun-Chul;Jang, Joon-Yung;Park, Se-Joon;Cha, Eun-Sun;Lee, Hyuk
    • The Korean Journal of Nuclear Medicine Technology
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    • v.21 no.2
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    • pp.74-79
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    • 2017
  • Purpose Proton therapy can deliver an optimal dose to tumor while reducing unnecessary dose to normal tissue as compared the conventional photon therapy. As proton beams are irradiated into tissue, various positron emitters are produced via nuclear fragmentation reactions. These positron emitters could be used for the dose verification by using PET. However, the short half-life of the radioisotopes makes it hard to obtain the enough amounts of events. The aim of this study is to investigate the effect of off-line PET imaging scan time on the PET image quality. Materials and Methods The various diameters of spheres (D=37, 28, 22 mm) filled with distilled water were inserted in a 2001 IEC body phantom. Then proton beams (100 MU) were irradiated into the center of the each sphere using the wobbling technique with the gantry angle of $0^{\circ}$. The modulation widths of the spread out bragg peak were 16.4, 14.7 and 9.3 cm for the spheres of 37, 28 and 22 mm in diameters respectively. After 5 min of the proton irradiation, the PET images of the IEC body phantom were obtained for 50 min. The PET images with different time courses (0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min) were obtained by dividing the frame with a duration of 10 min. In order to evaluate the off-line PET image quality with the different time courses, the contrast-to-noise ratio (CNR) of the PET image calculated for each sphere. Results The CNRs of the sphere (D=37 mm) were 0.43, 0.42, 0.40, 0.31 and 0.21 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNRs of the sphere (D=28 mm) were 0.36, 0.32, 0.27, 0.19 and 0.09 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNR of 37 mm sphere was decreased rapidly after 30 min of the proton irradiation. In case of the spheres of 28 mm and 22 mm, the CNR was decreased drastically after 20 min of the irradiation. Conclusion The off-line PET imaging time is an important factor for the monitoring of the proton therapy. In case of the lesion diameter of 22 mm, the off-line PET image should be obtained within 25 min after the proton irradiation. When it comes to small size of tumor, the long PET imaging time will be beneficial for the proton therapy treatment monitoring.

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Antioxidant Activity of Solvent Extracts from Sargassum thunbergii (지충이 용매 추출물의 항산화 활성)

  • Choi, Sun-Young;Kim, Soon-Young;Hur, Jong-Moon;Choi, Han-Gil;Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.2
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    • pp.139-144
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    • 2006
  • In this study, we investigated the antioxidant activity of solvent extracts from Sargassum thunbergii by measuring electron-donating ability (EDA), nitrite- scavenging ability, superoxide dismutase (SOD)-like activity, reducing power and antioxidant activity in $\beta-carotene-linoleate$ model system. Total phenolic compound contents of chloroform and methanol extracts from Sargassum thunbergii were $22.5{\pm}0.8$ mg/100 mL and $20.1{\pm}0.6$ mg/100 mL, respectively. The EDA were proportionally increased with concentration of the extracts except hexane extract. The EDAs were $70.4\%\;and\;63.2\%$ in methanol and water at concentration of $1000{\mu}g/mL$, respectively. The nitrite-scavenging ability of methanol extract (pH 2.5, $1000{\mu}g/mL$) was $89.4{\pm}0.9\%$ that was higher than those of other extracts. SOD-like ability of chloroform extract was stronger than other extracts. Reducing power of chloroform extracts at $1000{\mu}g/mL$ were 0.75 as O.D. value of 700 nm and antioxidant activities measured with $\beta-carotene-linoleate$ model system were in order of methanol $(78.4\%)>BHT\;(72.1\%)>chloroform\;(62.2\%)>water\;(51.4\%)>hexane\;(43.2\%)$. These results indicated that methanol extract from Sargassum thunbergii showed the highest activities on the EDA, nitrate- scavenging ability and antioxidant activities while the chloroform extract had the highest effect on the SOD-like activity and reducing power.

Effects of Gamma Irradiation on Color Changes and Biological Activities of Ethanol Extract of a Mechanically Pressed Juice of Bokbunja (Rubus coreanus Miq.) (감마선 조사에 의한 복분자 착즙액 에탄올 추출물의 색상 및 생리활성 변화)

  • Kim, Hee-Jung;Jo, Cheor-Un;Kim, Hyun-Joo;Shin, Dong-Hwa;Son, Jun-Ho;Byun, Myung-Woo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.3
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    • pp.271-277
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    • 2006
  • A mechanically pressed juice of Bokbunja (Rubus coreanus Miq.) extract was prepared using 70% ethanol solution. The extract was subjected to gamma-irradiation treatment (20 kGy) and investigated for its change of color and biological activities. Hunter $L^*$ values of the irradiated Bokbunja extract were increased in comparison with the non-irradiated extracts, and the $a^*\;and\;b^*$values decreased by the irradiation treatment. The content of the total phenolic compounds in the non-irradiated and irradiated extracts were 58.4 and 56.5 mg/g, respectively. The 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activities of non-irradiated and irradiated extracts at a 250 ppm level were 80% and 79%, respectively. Lipid oxidation was retarded by addition of Bokbunja powder. Nitrite scavenging activity was the highest in the Bokbunja powder at pH 1.2 and the effect was not changed by irradiation. The Bokbunja powder showed antimicrobial activity against Salmonella Typhimurium and Bacillus cereus. However, irradiation of Bokbunja did not affect any physiological functions (p>0.05). A Salmonella mutagenicity assay indicated that the irradiated Bokbunja extract did not show any mutagenicity. Therefore, Bokbunja extract could be used in various applications as a functional material, such as ingredients of food and cosmetic, compositions with functions.

The Anticancer Effect and Mechanism of Photodynamic Therapy Using 9-Hydroxypheophorbide-a and 660 nm Diode Laser on Human Squamous Carcinoma Cell Line. (9-hydroxypheophorbide-a와 660 nm 다이오드 레이저를 이용한 광역학치료의 항암효과와 치료기전에 대한 연구)

  • Ahn, Jin-Chul
    • Journal of Life Science
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    • v.19 no.6
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    • pp.770-780
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    • 2009
  • A new photosensitizer, 9-Hydroxypheophorbide-a (9-HpbD-a), was derived from Spirulina platensis. We conducted a series of experiments, in vitro and in vivo, to evaluate the anticancer effect and mechanism of photodynamic therapy using 9-HpbD-a and 660 nm diode lasers on a squamous carcinoma cell line. We studied the cytotoxic effects of pheophytin-a, 9-HpbD-a, 9-HpbD-a red and 660 nm diode lasers in a human head and neck cancer cell line (SNU-1041). Cell growth inhibition was determined by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The effects of 9-HpbD was higher than those of 9-HpbD-a red or pheophytin-a in PDT. We then tested the cytotoxic effects of 9-hydroxypheophorbide-a (9-HpbD-a) in vitro. The cultured SNU-I041 cells were treated with serial concentrations of 9-HpbD-a followed by various energy doses (0, 0.1, 0.5, 3.2 J/$cm^{2}$) and by various interval times (0, 3, 6, 9, 12 hr) until laser irradiation, then MTT assay was applied to measure the relative inhibitory effects of photodynamic therapy (PDT). Optimal laser irradiation time was 30 minutes and the cytotoxic effects according to incubation time after 9-HpbD-a treatment increased until 6 hours, after which it then showed no increase. To observe the cell death mechanism after PDT, SUN-I041 cells were stained by Hoechst 33342 and propidium iodide after PDT, and observed under transmission electron microscopy (TEM). The principal mechanism of PDT at a low dose of 9-HpbD-a was apoptosis, and at a high dose of 9-HpbD-a it was necrosis. PDT effects were also observed in a xenografted nude mouse model. Group I (no 9-HpbD-a, no laser irradiation) and Group II (9-HpbD-a injection only) showed no response (4/4, 100%), and Group III (laser irradiation only) showed recurrence (1/4,25%) or no response (3/4, 75 %). Group IV (9-HpbD-a + laser irradiation) showed complete response (10/16, 62.5%), recurrence (4/16, 25%) or no response (2/16, 12.5%). Group IV showed a significant remission rate compared to other groups (p<0.05). These results suggest that 9-HpbD-a is a promising photosensitizer for the future and that further studies on biodistribution, toxicity and mechanism of action would be needed to use 9-HpbD-a as a photosensitizer in the clinical setting.

Radiation Therapy in Elderly Skin Cancer (노령의 피부암에서 방사선치료)

  • Kim, Jin-Hee
    • Radiation Oncology Journal
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    • v.26 no.2
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    • pp.113-117
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    • 2008
  • Purpose: To evaluate the long term results(local control, survival, failure, and complications) after radiation therapy for skin cancer in elderly patients. Material and Methods: The study spanned from January 1990 to October 2002. Fifteen elderly patients with skin cancer were treated by radiotherapy at the Keimyung University Dongsan Medical Center. The age distribution of the patients surveyed was 72 to 95 years, with a median age of 78.8 years. The pathologic classification of the 15 patients included squamous cell carcinoma(10 patients), basal cell carcinoma(3 patients), verrucous carcinoma(1 patient) and skin adnexal origin carcinoma(1 patient). The most common tumor location was the head(13 patients). The mean tumor diameter was 4.9 cm(range 2 to 9 cm). The radiation dose was delivered via an electron beam of 6 to 15 MeV. The dose range was adjusted to the tumor diameter and depth of tumor invasion. The total radiation dose ranged from $50{\sim}80$ Gy(mean: 66 Gy) with a 2 Gy fractional dose prescribed to the 80% isodose line once a day and 5 times a week. One patient with lymph node metastasis was treated with six MV photon beams boosted with electron beams. The length of the follow-up periods ranged from 10 to 120 months with a median follow-up period of 48 months. Results: The local control rates were 100%(15/15). In addition, the five year disease free survival rate(5YDFS) was 80% and twelve patients(80%) had no recurrence and skin cancer recurrence occurred in 3 patients(20%). Three patients have lived an average of 90 months($68{\sim}120$ months) without recurrence or metastasis. A total of 9 patients who died as a result of other causes had a mean survival time of 55.8 months after radiation therapy. No severe acute or chronic complications were observed after radiation therapy. Only minor complications including radiation dermatitis was treated with supportive care. Conclusion: The results suggest that radiation therapy is an effective and safe treatment method for the treatment of skin cancer in elderly patients who achieved a good survival rate and few minor complications.

Antioxidative and Biological Activites of Extracts of Sweetpotato Tips (고구마 끝순 추출물이 알코올 투여 흰쥐의 항산화 효소계 및 지질과산화에 미치는 영향)

  • Lee, Joon-Seol;Park, Yang-Kyun;Ahn, Young-Sup;Kim, Hag-Sin;Chung, Mi-Nam;Jeong, Byeong-Choon;Bang, Jin-Ki
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.52 no.4
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    • pp.411-420
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    • 2007
  • This study was conducted to increase sweetpotato utilization and to determine the vegetative value of sweetpotato tips by investigating the phenolic compounds, antioxidative effect in oil, electron donating ability, nitrite scavenging effect and ACE inhibition activities. The phenolic compounds present in sweetpotato tips are the gallic, chlorogenic, gentisic, caffeic, couramic and ferulic acid, which are 16-122 times higher compared to other vegetables such as spinach, soybean sprout, and perilla leaves. In each solvent extract, the total phenolic compounds(175.8 mg/g) was composed of 55% EtOAc extraction and 39% BuOH extract, respectively. The results of induction period using the Rancimat method showed that the antioxidant activity of SP tips was higher than the tocopherol or BHT. The relative levels of each solvent extract in SP tips were as follows: EtOAc>BHT>BuOH>Tocopherol>Water>$CHCl_3$>Hexane. The peroxide value was measured every 5 days for 25 days during storage and results showed that the peroxide value, the tips, tuberous root and tocopherol were lower compared to spinach, soybean sprout and perilla leaves. Nitrite scavenging effects were excellent in sweetpotato tips, perilla leaves and soybean sprout, especially, inhibition rate of perilla leaves(72%) were superior to the others. In process of solvent extraction, activity of BuOH and water extractions were the best. ACE inhibition activity in sweetpotato tips was 1.5 times higher than in tuberous roots and $1.9{\sim}3.7$ times higher than in spinach, soybean sprout, perilla leaves.

The Research to Correct Overestimation in TOF-MRA for Severity of Cerebrovascular Stenosis (3D-SPACE T2 기법에 의한 TOF-MRA검사 시 발생하는 혈관 내 협착 정도의 측정 오류 개선에 관한 연구)

  • Han, Yong Su;Kim, Ho Chul;Lee, Dong Young;Lee, Su Cheol;Ha, Seung Han;Kim, Min Gi
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.12
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    • pp.180-188
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    • 2014
  • It is very important accurate diagnosis and quick treatment in cerebrovascular disease, i.e. stenosis or occlusion that could be caused by risk factors such as poor dietary habits, insufficient exercise, and obesity. Time-of-flight magnetic resonance angiography (TOF-MRA), it is well known as diagnostic method without using contrast agent for cerebrovascular disease, is the most representative and reliable technique. Nevertheless, it still has measurement errors (also known as overestimation) for length of stenosis and area of occlusion in celebral infarction that is built by accumulation and rupture of plaques generated by hemodynamic turbulence. The purpose of this study is to show clinical trial feasibility for 3D-SPACE T2, which is improved by using signal attenuation effects of fluid velocity, in diagnosis of cerebrovascular disease. To model angiostenosis, strictures of different proportions (40%, 50%, 60%, and 70%) and virtual blood stream (normal saline) of different velocities (0.19 ml/sec, 1.5 ml/sec, 2.1 ml/sec, and 2.6 ml/sec) by using dialysis were made. Cross-examinations were performed for 3D-SPACE T2 and TOF-MRA (16 times each). The accuracy of measurement for length of stenosis was compared in all experimental conditions. 3D-SPACE 2T has superiority in terms of accuracy for measurements of the length of stenosis, compared with TOF-MRA. Also, it is robust in fast blood stream and large stenosis than TOF-MRA. 3D-SPACE 2T will be promising technique to increase diagnosis accuracy in narrow complex lesions as like two cerebral small vessels with stenosis, created by hemodynamic turbulence.

Biological Activities of Yuza Grown in Different Areas (산지별 유자의 생리활성)

  • Shin, Jung-Hye;Lee, Soo-Jung;Kang, Min-Jung;Yang, Seung-Mi;Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.11
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    • pp.1485-1491
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    • 2009
  • The biological compounds such as vitamin C, carotenoids, hesperidin and naringin were determined in Yuza grown in Geoje, Goseong, Gohung and Namhae. Also, activities of electron donating, nitrite scavenging and tyrosinase were detected by concentration of water extracts made from Yuza peel. Vitamin C contents of flesh sample were 6.34${\Pm}$0.12-10.74${\Pm}$1.25 mg/100 g and its contents of peel were 2.17-3.57 times higher than flesh. The carotenoid contents of peel were higher than flesh, and its contents were abundant (over 6.0 mg/100 g) in peel of Yuza grown in Goseong and Namhae-native, while Goheung-native and improved samples were detected below 3.6 mg/100 g. The contents of total phenols were the highest in flesh (11.11${\Pm}$0.10 mg/100 g) and peel (31.76 mg/100 g) of Namhae-improve Yuza. The contents of hesperidin and naringin were about 4.81-7.80, 3.07-4.62 times higher in peel than flesh. Electron donating ability of water extracts made from Yuza peel was 52.78${\Pm}$1.13-66.88${\Pm}$0.53%, in over 5 mg/mL; especially, its ability in Namhae sample was significantly high in reaction system added over 5 mg/mL of water extracts. Nitrite scavenging ability in all samples was below 30% in reaction system added 1 mg/mL of water extracts. Inhibition activity of tyrosinase in reaction system added 2.5 mg/mL of water extracts was only observed in Namhae samples, but the other samples were increased in reaction system added over 5 mg/mL of water extracts.

Types and Ultrastructural Characteristics of Antennal Sensilla on Aphidius colemani (Hymenoptera: Braconidae) (콜레마니진디벌(Aphidius colemani) 촉각에 분포하는 감각기의 종류 및 외부미세구조적 특징)

  • Kwon, Hye-Ri;Yoon, Kyu-Sik;Kang, Min-A;Park, Min-Woo;Jo, Shin-Hyuk;Kang, Eun-Jin;Seo, Mi-Ja;Yu, Yong-Man;Youn, Young-Nam
    • Korean journal of applied entomology
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    • v.49 no.4
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    • pp.277-287
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    • 2010
  • Several species of the genus Aphidius are used in biological control programs against aphid pests throughout the world and their behavior and physiology are well studied. While the importance of sensory organs in their behavior is understood, their antennal structure remains largely unknown. In this study, the external morphology and distribution of the antennal sensilla on the antennal of both female and male adults of A. colemani were described using scanning electron microscopy (SEM). Generally, the filiform antennae of males ($l,515.2{\pm}116.5\;{\mu}m$) are longer than females ($l,275.1{\pm}103.4\;{\mu}m$). Antennae of this species are made up of radicle, scape, pedicel and flagellomeres. Male and female antennae differed in the total number of flagellomeres as 15 in males and 13 in females. The result of SEM observation was characterization and grouping of seven types of receptors into morphological classcs: Bohm bristles, Sensilla placodea, 2 types of S. coeloconica and S. trichodea, and S. basiconica as with a tip pore and with wall pores. In addition, the possible functions of the above sensilla types arc discussed in light of previously published literature; mechanoreception (Bohm bristles, S, coeloconica I & II and S. trichodea) and chemoreception (S. placodea, S. basiconica type I & II).