휴먼형 로봇 손의 사물 조작 수행을 이용한 인간 행동 복제 강화학습 정책 최적화 방법 성능 평가

박나현 ( Na Hyeon Park ),오지헌 ( Ji Heon Oh ),류가현 ( Ga Hyun Ryu ),( Edwin Valarezo Añazco ),( Patricio Rivera Lopez ),원다슬 ( Da Seul Won ),정진균 ( Jin Gyun Jeong ),장윤정 ( Yun Jung Chang ),김태성 ( Tae-seong Kim ) 한국정보처리학회 2020 한국정보처리학회 학술대회논문집 Vol.27 No.2

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.

Selective Electrochemical Detection of Dopamine Using Reduced Graphene Oxide Sheets-Gold Nanoparticles Modified Electrode

Park, Da-Jeong,Choi, Jin-Ha,Lee, Won-Jin,Um, Soong Ho,Oh, Byung-Keun American Scientific Publishers 2017 Journal of nanoscience and nanotechnology Vol.17 No.11

<P>Dopamine (DA) is one of the most significant neurotransmitters, and it has a major role in the central nervous system, such as in cognition, motivation, and memory. Some neural diseases, including Alzheimer's disease (AD) and Parkinson's diseases (PD), are related with a lack of DA. Thus, the detection of DA is necessary for the early diagnosis of such diseases. In this study, we fabricate an electrochemical sensor by modifying an electrode with reduced graphene oxide sheet (rGS)-gold nanoparticle (GNP) complexes to determine DA and ascorbic acid (AA) in a mixture within a range of 0.1-100 mu M. The rGS was used to improve the selectivity of the sensor by having pi-pi interaction with DA, and the GNPs improved the sensitivity due to their great conductivity and large surface area. As a result, when the GNPs were immobilized on the rGS surface, the sensor exhibited greatly improved electrocatalytic activity compared with other cases, such as the individual application of rGS or GNPs. The performance of the sensor with the modified electrode was confirmed by scanning electron microscopy (SEM), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) measurements. The results showed that it had linearity in the range of 0.1-100 mu M of DA and the limit of detection was 0.098 mu M in the presence of AA 400 mu M. Therefore, it could be applied to medical biosensors to diagnose neural diseases.</P>

Enhanced Systemic siRNA Delivery Using Reducible Bile Acid-modified PEI for Cancer Therapy

Chae eun PARK,Su yeon LIM,Da hwun KIM,Siyan LYU,Byung deok KIM,Oui bo WHANG,Ji hoon JEONG 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10

Small interfering RNA (siRNA) contributes to RNA interference(RNAi) by inhibiting target gene expression in a sequence-specific manner. siRNA delivery system have become increasingly popular for cancer therapy. In this study, we used a low molecular weight polyethylenimine (PEI, 1.8 kDa) conjugated with deoxycholic acid (DA). A DA-PEI conjugate was further modified with 4-fluorothiophenol (4-FTP) (4-FTP-DA-PEI) to enhance systemic siRNA delivery. The thiophenol group would be involved with disulfide bonds between the polymer chains and siRNA modified with free thiols (thiol-siRNA) to form and π-π interactions between the pendent aromatic groups and coprostane ring of the bile acid. The stabilized TP-DA-PEI conjugate with thiol-siRNA achieved developed intracellular uptake, serum stability, and transfection efficiency. Furthermore, it shows high accumulation of TP-DA-PEI/thiol-siRNA polyplexes and significant tumor growth inhibition effect in tumor-bearing mice after systemic administration.

모유 수유아와 조제 분유 영양아에서 수유 방법에 따른 아미노산 농도 비교 및 혈청 트립토판 농도와 수면 유도와의 관계

정다운,김은영,양은석,박상기,박영봉,문경래 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.2

Objective: Sleep behavior is modulated by serotonergic neurons within the brain, and the synthesis and release of serotonin by such neurons is thought to be influenced by the availability of tryptophan, the amino acid precursor of serotonin. Formula-feeding infants have depressed plasma tryptophan concentration relative to breast milk-feeding infants. Because tryptophan alters sleep waking patterns in adults, a study was designed to determine the difference of sleep latency relative to differences in plasma tryptophan and tryptophan : large neutral amino acid (LNAA) ratio between formula-feeding infants and breast milk-feeding infants. Method: 45 newborns who were born in Chosun University Hospital from December 2002 to December 2003 were selected. The newborns were divided to three group, 15 newborns were fed breast milk and 15 newborns were fed formula A, and last 15 newborns were fed formula B. At 6 weeks and 12 weeks, infants were sampled for measuring of serum amino acid level and tryptophan, tryptophan : LNAA ratio. And we taught infants' parents to measure sleep latency that means the time after a feeding to the first episode of active REM sleep that persist ≥ 1 min. Result: 1) At 6weeks, Serum α-amino-n-butyric acid, citrulline, tryptophan level was higher in formula A group than breastmilk group (P<0.05) and proline level was lower than breast milk group (P<0.05). In formula B group, serum n-amino-n-buryric acid, citrulline, cystine, hydroxylysine, hydroxyproline, isoleucine, leucine, lysine, methionine, phenylalanine, taurine, threonine, valine levels were higher than breastmilk group (P<0.05). And Serum isoleucine, methionine, proline, valine level were higher in formula B group than formula A group (P<0.05). 2) At 12 weeks, serum glutamic acid, methionine, ornithine levels were higher in formula group A than breast milk group (P<0.05). Serum β-alanine, aspartic acid, α-amino-n-butyric acid, ethanolamine, glutamic acid, threonine level were higher in formula B group than breast milk group (P<0.05). Serum β-alanine, ethanolamine levels were higher and arginine level was lower in formula B group than formula A (P<0.05). 3) At 6 weeks, serum tryptophan concentration and tryptophan: LNAA ratio were higher in formula A group (P<0.05). Sleep latency was 21 minutes in formula group A, 24 minutes in breast milk group, 25 minutes in formula B group but there was no statistically significance (P>0.05). 4) At 12 weeks, serum tryptophan concentration and tryptophan: LNAA ratio, time after feeding to the first episode of active REM sleep were no difference with each other group. Conclusion: There is significant difference of serum amino acids between breast-feeding infants and formula-feeding infants. And serum tryptophan and tryptophan: LNAA ratio differ between brest-feeding infants and formula-feeding infants. But there is no association between serum tryptophan, tryptophan: LNM ratio and sleep latency.

八味元이 Streptozotocin 糖尿病에 미치는 影響

김희경,문정숙,박귀영,이다미,이은영,장윤경,황미경 曉星女子大學校 藥學大學 學生會 1988 曉星藥誌 Vol.4 No.-

Streptozotocin was injected to rats and rabbits to induce the experimental diabetes mellitus and Palmiwon was administrated to observe the changes of blood sugar, body weight, and serum Zn, Ca, Mg level in order to find out the effect of diabetic tratment by experimental method. And thus, the result was as follows: 1. The blood sugar level of diabetic rat was decreased after administration of Palmiwon. 2. Body weight of diabetic rat was moderately decreased after administratin of Palmiwon. 3. The less streptozotocin, 30 mg/kg, don't easily induce diabetes mellitus in rabbits. We did not find the changes of blood sugar, serum Zn, Ca, Mg level in the rabbits injected by streptozotocin, 30mg/kg of body weight.

행동 복제 강화학습 및 딥러닝 사물 부분 검출 기술에 기반한 사람형 로봇손의 사물 조작

오지헌 ( Ji Heon Oh ),류가현 ( Ga Hyun Ryu ),박나현 ( Na Hyeon Park ),( Edwin Valarezo Añazco ),( Patricio Rivera Lopez ),원다슬 ( Da Seul Won ),정진균 ( Jin Gyun Jeong ),장윤정 ( Yun Jung Chang ),김태성 ( Tae-seong Kim ) 한국정보처리학회 2020 한국정보처리학회 학술대회논문집 Vol.27 No.2

최근 사람형(Anthropomorphic)로봇손의 사물조작 지능을 개발하기 위하여 행동복제(Behavior Cloning) Deep Reinforcement Learning(DRL) 연구가 진행중이다. 자유도(Degree of Freedom, DOF)가 높은 사람형 로봇손의 학습 문제점을 개선하기 위하여, 행동 복제를 통한 Human Demonstration Augmented(DA)강화 학습을 통하여 사람처럼 사물을 조작하는 지능을 학습시킬 수 있다. 그러나 사물 조작에 있어, 의미 있는 파지를 위해서는 사물의 특정 부위를 인식하고 파지하는 방법이 필수적이다. 본 연구에서는 딥러닝 YOLO 기술을 적용하여 사물의 특정 부위를 인식하고, DA-DRL 을 적용하여, 사물의 특정 부분을 파지하는 딥러닝 학습 기술을 제안하고, 2 종 사물(망치 및 칼)의 손잡이 부분을 인식하고 파지하여 검증한다. 본 연구에서 제안하는 학습방법은 사람과 상호작용하거나 도구를 용도에 맞게 사용해야하는 분야에서 유용할 것이다.

Multiple reassortant bovine G8 and G6 rotaviruses

Da Hae Park,Sang Ik Park,Sung Hee Park,Linda J. Saif,Young Ju Jeong,Hyun Jeong Kim,Myra Hosmillo,Hyung Jun Kwon,Dong Jun Shin,Young Hyun Chun,Mun Il Kang,Kyoung Oh Cho,Su Jin Park 대한수의학회 2009 대한수의학회 학술대회발표집 Vol.2009 No.-

심사정의 한국화(화훼초충도) 특징 분석

박정은 ( Jeong Eun Park ),정다운 ( Da Uon Chung ),정찬기오 ( Chan Gi Oh Chung ) 경상대학교 중등교육연구소 2015 중등교육연구 Vol.27 No.-

본 연구의 목적은 조선시대의 대표적인 화가인 심사정의 한국화(화훼초충도) 특성을 분석하여 제시하는 것이다. 본 연구의 취지 및 필요성 그리고 연구목적에 근거하여 본 연구자가 설정한 구체적인 연구 문제는 심사정의 작품을 대표해 줄 수 있는 화훼초충도에는 어떤 작품들이 있는가, 심사정의 작품에 등장하는 화훼초충들의 의미는 어떤 것들인가 이다. 본 연구에 사용된 주된 자료는 심사정의 작품과 관련이 있는 석·박사 학위논문자료 16편과 단행본자료 22편, 학술지자료 6편과 신문자료 11종, 그리고 인터넷 사이트 14종 이였다. 연구 결과 자료들에 근거하여 제시할 수 있는 교육적인 의미는 심사정의 작품에서 주된소재가 된 꽃들-패랭이꽃, 모란, 백합, 장미, 원추리, 계화, 국화, 맨드라미, 양귀비, 달개비꽃, 부용화, 연꽃, 해당화 등-이 함축하고 있는 의미들인 젊음, 부귀영화, 장수와 풍요, 모성애와 근심 걱정을 털어버리는 의미인 망우, 아름다움과 향기, 장수와 참고 견딤, 입신출세, 생명력, 무한한 생명 등을 희망적이고 긍정적인 아이디어로 활용하는 것이 필요하다. 그리고 나비, 잠자리, 여치, 메뚜기, 벌, 매미, 베짱이, 사마귀, 무당벌레, 방아깨비 등과 같은 곤충 소재들이 함축하고 있는 의미들인 남녀화합과 행운, 다산과 득남, 벼슬, 부지런함과 충성, 청렴한 선비와 불멸, 출세, 과거급제 등을 희망적이고 긍정적인 아이디어로 활용하는 것이 필요하다고 할 수 있다. 뿐만 아니라, 선비의식과 지조의 의미를 함축하고 있는 괴석이나 지혜의 의미를 함축하고 있는 고슴도치 등도 희망적이고 긍정적인 아이디어로 활용하는 것이 필요하다. The purpose of this study is to suggest features of Korean Painting, Flower-Grass-Insect painted by representative artist Sim Sa-jeong in the period of Joseon dynasty after analyzing Flower-Grass-Insect painting. The specific research problems (the researcher focuses on) of this study based on the intent, necessity, and purpose regarding this study are to analyze certain works of flower-grass-insect painting representing the works of Sim Sa-jeong and specific meaning of flower-grass-insect painting. The main materials used in this study are 16 master′s and doctoral thesis, 22 published books, 6 academic journals, 11 newspaper articles, and 14 internet sites. Educational conclusion based on result of this study is that it is necessary to utilize implicative meaning such as youth, wealth and honor, longevity and richness, maternal love and narcotize one``s anxieties, beauty and fragrance, patience, and tenacious hold on life implied on subject matters of works by Sim Sa-jeong like china pink, peony, lily, rose, day lily, cassia flowers, chrysanthemum, cockscomb, poppy, spiderwort, Hibiscus mutabilis, lotus, sweetbrier and so on as hopeful and positive idea. Also, it is essential to make use of implied meaning such as harmony between man and woman and luck, fecundity, begetting a son, government position, diligence and fidelity, integrity and immortality, success, passing the state examination based on the subject matter of works of Sim Sa-jeong, butterfly, dragonfly, gampsocleis sedakovi obscura, grasshopper, bee, locust, wart. ladybug, long-headed grasshopper as affirmative and bright idea. Furthermore, this study suggests that oddly shaped stone implying the meaning of classical scholar and fidelity and hedgehog with the meaning of wisdom be utilized as positive and hopeful idea.

Effects of three-dimensional spheroid culture on equine mesenchymal stem cell plasticity

Park, Mi Jeong,Lee, Jienny,Byeon, Jeong Su,Jeong, Da-Un,Gu, Na-Yeon,Cho, In-Soo,Cha, Sang-Ho Elsevier 2018 Veterinary research communications Vol. No.

Epigenetic Changes in Asthma: Role of DNA CpG Methylation

( Da-jeong Bae ),( Ji Ae Jun ),( Hun Soo Chang ),( Jong Sook Park ),( Choon-sik Park ) 대한결핵 및 호흡기학회 2020 Tuberculosis and Respiratory Diseases Vol.83 No.1

For the past three decades, more than a thousand of genetic studies have been performed to find out the genetic variants responsible for the risk of asthma. Until now, all of the discovered single nucleotide polymorphisms have explained genetic effects less than initially expected. Thus, clarification of environmental factors has been brought up to overcome the ‘missing’ heritability. The most exciting solution is epigenesis because it intervenes at the junction between the genome and the environment. Epigenesis is an alteration of genetic expression without changes of DNA sequence caused by environmental factors such as nutrients, allergens, cigarette smoke, air pollutants, use of drugs and infectious agents during pre- and post-natal periods and even in adulthood. Three major forms of epigenesis are composed of DNA methylation, histone modifications, and specific microRNA. Recently, several studies have been published on epigenesis in asthma and allergy as a powerful tool for research of genetic heritability in asthma albeit epigenetic changes are at the starting point to obtain the data on specific phenotypes of asthma. In this presentation, we mainly review the potential role of DNA CpG methylation in the risk of asthma and its sub-phenotypes including nonsteroidal anti-inflammatory exacerbated respiratory diseases.