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.

Whole-genome resequencing analysis of 20 Micro-pigs

Da‑Hye Son,Nam‑Hyun Hwang,Won‑Hyong Chung,Ha‑Seung Seong,Hyungbum Lim,Eun‑Seok Cho,Jung‑Woo Choi,Kyung‑Soo Kang,Yong‑Min Kim 한국유전학회 2020 Genes & Genomics Vol.42 No.3

Background Miniature pigs have been increasingly used as mammalian model animals for biomedical research because of their similarity to human beings in terms of their metabolic features and proportional organ sizes. However, despite their importance, there is a severe lack of genome-wide studies on miniature pigs. Objective In this study, we performed whole-genome sequencing analysis of 20 Micro-pigs obtained from Medi Kinetics to elucidate their genomic characteristics. Results Approximately 595 gigabase pairs (Gb) of sequence reads were generated to be mapped to the swine reference genome assembly (Sus scrofa 10.2); on average, the sequence reads covered 99.15% of the reference genome at an average of 9.6-fold coverage. We detected a total of 19,518,548 SNPs, of which 8.7% were found to be novel. With further annotation of all of the SNPs, we retrieved 144,507 nonsynonymous SNPs (nsSNPs); of these, 5968 were found in all 20 individuals used in this study. SIFT prediction for these SNPs identified that 812 nsSNPs in 402 genes were deleterious. Among these 402 genes, we identified some genes that could potentially affect traits of interest in Micro-pigs, such as RHEB and FRAS1. Furthermore, we performed runs of homozygosity analysis to locate potential selection signatures in the genome, detecting several loci that might be involved in phenotypic characteristics in Micro-pigs, such as MSTN, GDF5, and GDF11. Conclusion In this study, we identified numerous nsSNPs that could be used as candidate genetic markers with involvement in traits of interest. Furthermore, we detected putative selection footprints that might be associated with recent selection applied to miniature pigs.

교내 실내 공기에서 부유 미생물의 분포

박창은,임미소,이다은,김설아,강재원 남서울대학교 2010 남서울대학교 논문집 Vol.16 No.2

The pathogenic and non-pathogenic microorganism have been isolated from the indoor airborne, the closest environment of human beings. Our purpose were to investigate the distribution of fungi and bacteria in indoor airborne sampled from 7 locations in Namseoul University for 2 months from September to October, 2010. The isolated bacteria were identified by Gram stain and biochemical test using VITEKTM system, also The fungus were identified by LPCB. The experiment on microorganism concentration of indoor air carried out and the average of total microorganism was measured. When airborne bacteria were isolated and identified. The isolation rates of Gram positive cocci, Gram positive bacilli, Gram negative bacilli, and Gram negative cocci were 38.3%, 22.4%, 2.7%, 0%, respectively. In Gram positive cocci, the most strains were identified as Micrococcus spp. In Gram positive bacilli, the most strains were identified as Bacillus spp. The frequently isolated fungi were Aspergillus sp, Penicillium sp, Alternaria sp, Rhizopus sp, Mucor sp. respectively. Further systematic studies are necessary with an emphasis on species identification. Key Words : Microorganism, Fungus, Indoor Airborne, Micrococcus, Aspergillus

사무직 근로자의 수면의 질 및 직무스트레스와 우울과의 관련성

강미나,강수영,권수정,김현주,배재원,이보연,이예진,임의롬,정다영,조한솔 이화여자대학교 간호과학대학 2013 이화간호학회지 Vol.- No.47

Purpose: The purpose of this study was to understand the degree of depression, sleep quality, job stress and their association among office workers. Method: A self-administered questionnaire was distributed to 147 workers employed in 5 big enterprises, and 5 small and medium enterprises from October 21 to November 21, 2012. The questionnaires included socio-demographic and health-related characteristics, job-related characteristics, sleep quality, job stress (KOSS) and depression (CES-D). Result: Among all subjects, 23.1% was in the depression group (21 points and over in the CES-D score). Depressive level was positively correlated with job stress and quality of sleep. The adjusted odd ratio for the effects of sleep quality and job stress on depression significantly increased in the depression group compared to that of the normal group. Multiple regression analysis revealed that the following factors of influence had combined explanatory powers on depression: BMI, life satisfaction, quality of sleep, and job stress. Conclusion: The study revealed that complicated influences were exerted on the level of depression by variable factors, as well as socio-demographic characteristics, health-related characteristics, quality of sleep, and job stress. Specifically, the level of depression was influenced by the quality of sleep and job stress.

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.

Does Diabetes Mellitus Influence Standardized Uptake Values of Fluorodeoxyglucose Positron Emission Tomography in Colorectal Cancer?

( Da Yeon Oh ),( Ji Won Kim ),( Seong Joon Koh ),( Mingoo Kim ),( Ji Hoon Park ),( Su Yeon Cho ),( Byeong Gwan Kim ),( Kook Lae Lee ),( Jong Pil Im ) 대한장연구학회 2014 Intestinal Research Vol.12 No.2

Background/Aims: Hyperglycemia is associated with decreased 2-18[F]fluoro-2-deoxy-D-glucose (FDG) uptake by tumorsassessed by positron emission tomography (PET). In this retrospective study we investigated a comparison of standardizeduptake values (SUVs) in patients with primary colorectal cancers who either had diabetes mellitus (DM) or were otherwisehealthy. Methods: The medical records of 397 patients who were diagnosed with colorectal cancer and underwent PETCTbetween January 2006 and December 2012 were analyzed. Eighty patients with DM and 317 patients without DM wereincluded. Clinical characteristics were reviewed and maximal standardized uptake values (SUVmax) were calculated in the primarycolorectal lesions. Results: There was no significant difference between tumor SUVmax in DM patients (10.60±5.78) andthose without DM (10.92±5.44). In addition, no significant difference was detected between tumor SUVmax in DM patients withglycated hemoglobin (HbA1c) levels <8% (10.34±5.17) and those with HbA1c levels ≥8% (10.61±7.27). The maximum size ofthe primary colorectal tumor was associated with SUVmax in a linear regression analysis. Conclusion: The results of this studyshowed that DM did not influence FDG uptake values in colorectal cancer patients regardless of glucose levels. (Intest Res2014;12:146-152)

The combined clinical impact of red blood cell distribution width and vascular calcification on cardiovascular events and mortality in patients with endstage kidney disease

Kim Da Won,Lee Munpyo,Lee Kwon Jae,Lee Yeon Hee,Kim Dongryul,신석준,윤혜은 대한신장학회 2022 Kidney Research and Clinical Practice Vol.41 No.3

Background: Little is known about how the interaction between red blood cell distribution width (RDW) and vascular calcification (VC) affects cardiovascular (CV) events and mortality in end-stage kidney disease (ESKD) patients. This study investigated the combined prognostic effect of RDW and VC in ESKD patients starting dialysis. Methods: A retrospective single-center study of 582 ESKD patients was conducted. VC was assessed by calculating the aortic calcification index (ACI) using computed tomography. Patients were divided into low ACI-low RDW, low ACI-high RDW, high ACI-low RDW, and high ACI-high RDW groups based on median ACI (17.12) and RDW (14.3) values. The association between RDW and VC and the composite endpoint of CV events and death was analyzed. Results: During a median follow-up of 3.1 years (range, 1.5–5.5 years), 165 CV events (28.4%) and 124 deaths (21.4%) occurred. Cox regression showed that the low ACI-high RDW (adjusted hazard ratio [HR], 1.66; 95% confidence interval [CI], 1.04–2.66; p = 0.03) and high ACI-low RDW (adjusted HR, 1.95; 95% CI, 1.21–3.14; p = 0.006) groups had a greater risk of CV events and death than the low ACI-low RDW group. The high ACI-high RDW group had the greatest risk (adjusted HR, 2.23; 95% CI, 1.42–3.52; p = 0.001). The effect of the interaction between ACI and RDW on CV events and mortality was statistically significant (p = 0.005). Conclusion: High RDW and VC interact to increase the risk of CV events and death in ESKD patients.

Case Report : Severe Hyponatremia Associated with the Use of Angiotensin II Receptor Blocker/thiazide Combinations

( Da Rae Kim ),( Joo Hee Cho ),( Won Seok Jang ),( Jin Sug Kim ),( Kyung Hwan Jeong ),( Tae Won Lee ),( Chun Gyoo Ihm ) 대한전해질학회 2013 Electrolytes & Blood Pressure Vol.11 No.2

There are several widely used combinations of angiotensin II receptor blocker (ARB)/ thiazide. The complimentary mechanism of action for such antihypertensive therapies is that, while ARB inhibits the vasoconstricting and aldosterone-secreting effects of angiotensin II, hydrochlorothiazide affects the renal tubular mechanisms of electrolyte reabsorption and increases excretion of sodium and chloride in the distal tubule, consequently promoting water excretion. In addition, hypokalemia, which may be triggered by a hydrochlorothiazide-induced increase in urinary potassium loss, is resisted by the use of ARB. Hence, the ARB/thiazide combination is safe in terms of potassium imbalance. For these reasons, fixed-dose ARB/thiazide combination anti-hypertensive drugs have been widely used for the treatment of hypertension. However, there have not been many studies done regarding cases where patients under such regimens showed severe hyponatremia,even when the amount of thiazide included was low. Here we report two cases in which severe hyponatremia occurred following treatment with the ARB/thiazide combinations. Upon discontinuation of the regimen, both patients showed recovery from hyponatremia.

Pulmonary embolism caused by huge popliteal venous saccular aneurysm: A case report

( Da Won Park ),( Ji Won Jang ),( Song-yi Kim ) 대한내과학회 2015 대한내과학회 추계학술대회 Vol.2015 No.1

A 67-year-old woman presented with atypical chest pain with shortness of breath on walking. The patient was bought to the emergency room for evaluation. Her physical examination did not reveal any pathology. The coronary angiogram and Echocardiogram revealed no significant finding except mild septal bouncing of LV wall. At the night of admission day, multiple syncopal episode with transient shock were observed. A CT angiogram revealed multiple bilateral filling defects diagnostic of multiple bilateral pulmonary emboli (Fig. 1A) and enlargement of right popliteal vein. A lower extremity ascending venogram revealed aright saccular popliteal vein aneurysm (PVA) that measured 3.5 cm in diameter and filled with floating thrombus(Fig. 1B). Laboratory test revealed no evidence of hypercoagulative state. A preoperative inferior vena cava (IVC) filter was inserted into infrarenal IVC and the patient was anticoagulated with heparin and warfarin for preoperative period. 2 months later, a lateral tangential aneurysmectomy was performed to prevent a recurrence of pulmonary embolism on posterior approach via an S-shaped incisionto the popliteal fossa (Fig. 1C). The lateral venorrhaphy was primarily repaired. The opened aneurysm sac was filled with organizing thrombi and observed intima necrosis with medial hypertrophy. The patient was anticoagulated for 1 year. The patient has been asymptomatic for 1 year with no sign of deep venous insufficiency. A CT angiogram revealed patent repair with no evidence of deep venous thrombosis.

Two-dimensional nanocomposites based on tungsten oxide nanoplates and graphene nanosheets for high-performance lithium ion batteries

Kim, Da-Mi,Kim, Si-Jin,Lee, Young-Woo,Kwak, Da-Hee,Park, Han-Chul,Kim, Min-Cheol,Hwang, Bo-Mi,Lee, Seul,Choi, Jong-Ho,Hong, Seongho,Park, Kyung-Won Elsevier 2015 ELECTROCHIMICA ACTA Vol.163 No.-

<P><B>Abstract</B></P> <P>Well-defined nanocomposite electrodes based on active materials and graphene have been known to hold improved lithium ion reaction properties such as the lithium ion insertion/desertion reaction, cycle life, and high rate performance. Here, we report two-dimensional nanocomposites consisting of WO<SUB>3</SUB> nanoplates and graphene nanosheets (GNS) using a hydrothermal method and heating process for use in high-performance lithium ion batteries. A compilation of the data from XRD, SEM, and TEM suggests that the nanocomposites consist of high crystalline WO<SUB>3</SUB> nanoplates and GNS. The capacity and high rate cycling performance of the nanocomposites as an anode for lithium ion batteries are evaluated using coin cells. The nanocomposite electrode with an optimized amount of GNS exhibits high reversible capacity, good capacity retention, and excellent high rate cycling performance.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>