• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.49-58
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• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21st century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (Ipomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.71-73
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• 2001

In this study, we could improve transmission efficiency of germline chimeras by transfer of gonadal PGCs (gPGCs) cultured in vitro. Of hatched recipient chicks, 301 chickens (141 males and 160 females) were brought up to sexual maturity and these WLs (KOC) were mated with KOCs for testcross, resulting in 27 germline chimeras (15 males and 12 females) identified by black feather color of their progenies. The production efficiency of germline chimera production of experimental groups was observed (P=0.6831). The average transmission efficiency of proven germline chimeras was 0.6 ∼56.5% (15.0% on average). The transmission efficiency of experimental group which were transferred 10-days cultured gPGCs without Ficoll treatment was highest (49.7%) and that of experimental stock which transferred non-cultured gPGCs with Ficoll treatment was lowest (0.6%). The duration of in vitro culture before transferring was significantly important for the high efficiency of germline transmission. Transferring 10-days cultured gPGCs made the transmission efficiency higher rather than transferring non-cultured and 5-days cultured gPGCs, 50 times and 10 times, respectively (p<0.0001). However, Ficoll treatment for increasing the population ratio of gPGCs negatively affected the transmission efficiency and the effects of sexuality and the reciprocal interaction between treatments showed no significant differences. These findings demonstrated that the crucial factors for improving the germline transmission were the duration of in vitro culture prior to transfer. Thus, we developed the complete system for production of germline chimera using cultured gPGCs with highly improved efficiency and this system would be useful for genetic manipulation and obtaining the transgenic aves.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.86-88
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• 2001

An experiment was conducted to determine how broiler performance, feces and litter concentration of N can be maintained and whether NH3 gas concentration can be reduced with reducing dietary CP, adding ALUM(AL2(SO4)3.14H20) in litter and supplementing with amino acid and vitamin D in feed. The experiment was divided into a starter period(1 to 21d) and grower period(22 to 42d), each having three different CP with 90 birds per treatment of 3 replications. The CP treatments consisted of a mean CP of 23.0(control 71), 20.4 (72) and 18.0 (73) % for starter and 21.0(control 71),19.3 (72) and 17.0 (73) % for grower, respectively, but with similar amino acid levels as the control. Alum was mixed in each treatment except control treatment with 200g in kilogram litter(rice bran) weight. Results suggested that reducing CP below control in the diets fed during 3wks and 6wks slightly increased feed gain and slightly decreased feed intake and weight gain. However, there were no significant difference among treatments. Reducing CP caused NH3 gas concentration to decline by 74.8 - 80.9% when Alum was mixed in litter(P < 0.05). Litter N concentration did not show any difference(P > 0.05) among treatments. These results suggest that dietary manipulation with adding Alum in litter show for significant reducing NH3 gas concentration while maintaining acceptable Production performance from broiler.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.858-861
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• 2020

로봇이 사람과 같이 다양하고 복잡한 사물 조작을 하기 위해서 휴먼형 로봇손의 사물 파지 작업이 필수적이다. 자유도 (Degree of Freedom, DoF)가 높은 휴먼형(anthropomorphic) 로봇손을 학습시키기 위하여 사람 데모(human demonstration)가 결합된 강화학습 최적화 방법이 제안되었다. 본 연구에서는 강화학습 최적화 방법에 사람 데모가 결합된 Demonstration Augmented Natural Policy Gradient(DA-NPG)와 NPG 의 성능 비교를 통하여 행동 복제의 효율성을 확인하고, DA-NPG, DA-Trust Region Policy Optimization (DA-TRPO), DA-Proximal Policy Optimization (DA-PPO)의 최적화 방법의 성능 평가를 위하여 6 종의 물체에 대한 휴먼형 로봇손의 사물 조작 작업을 수행한다. 그 결과, DA-NPG 와 NPG를 비교한 결과를 통해 휴먼형 로봇손의 사물 조작 강화학습에 행동 복제가 효율적임을 증명하였다. 또한, DA-NPG 는 DA-TRPO 와 유사한 성능을 보이면서 모든 물체에 대한 사물 파지에 성공하여 가장 안정적이었다. 반면, DA-TRPO 와 DA-PPO 는 사물 조작에 실패한 물체가 존재하여 불안정한 성능을 보였다. 본 연구에서 제안하는 방법은 향후 실제 휴먼형 로봇에 적용하여 휴먼형 로봇 손의 사물조작 지능 개발에 유용할 것으로 전망된다.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.10.1-10
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• 1982

The use of phonosurgery in the recent development of laryngomicrosurgery has enabled the restoration of a normal voice in respect to functional laryngeal surgery which in Korea in the past limited to simple removal of benign laryngeal tumor such as laryngeal polyp or nodules and cordal injection of $Teflon^{{\circledR}}$ for the treatment of recurrent nerve paralysis under the vision of suspension laryngoscopy. Performance of phonosurgery for the treatment of cord paralysis, mutational dysphonia, vocal cord atrophy, hyperkinetic dysphonia and sulcus vocalis is a happy event in the view point of development of phonosurgery in Korea. In this aspect thyroplasty to change the position and physical characteristics of the cord outside the glottis instead of the direct handling of the vocal cord through direct endoscopy is popular. Among the 4 types of thyroplasty, classified by Insshiki(1974), type I thyroplasty(1ateral compression of vocal cord) and type IV thyroplasty(lengthening of vocal cord) were effective in the treatment of unilateral vocal cord paralysis. Advantages of this operation are the fine adjustment of the degree of lateral compression under local anesthesia according to the phonation of the patient during operation and avoidance of dyspnea and intralaryngeal hemorrhage due to the manipulation outside the internal perichondrium of the thyroid cartilage. We did 7 cases of thyroplasty for the treatment of unilateral vocal cord paralysis in the 7 months from September 1981 to March 1982. Before the operation aerodynamic study, psychoacoustical evaluation, stroboscopy and sound spectrographic analysis were done. Two months after the operation the above procedures were performed again. Results of preoperative and postoperative examination were compared and the following results were obtained. 1) In the aerodynamic study, maximum phonation time increased to 158% of the preoperative value and the phonation quotient and the mean flow rate decreased to 58% and 54% of preoperative values. 2) The degree of hoarseness improved in the psychoacoustical evaluation and the glottic chink during phonation was decreased in the stroboscopic examiantion. 3) In the sound spectrographic analysis, periodicity was much restored and noise distribution decreased especially in the high frequency area.