• 제목/요약/키워드: Oh Gyu-won

검색결과 292건 처리시간 0.026초

미러월드 연계를 통한 스마트폰에서의 위치기반 서비스 (A Location-based Service on Smartphone Combining with Mirror World)

  • 오규환;김재원;배경우
    • 한국게임학회 논문지
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    • 제11권1호
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    • pp.47-57
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    • 2011
  • 모바일 위치기반 서비스는 화면형태에 따라 지도, 조감화면, 사진 이미지, 현장영상 기반으로 구분 된다. 이 중 증강현실로 대표되는 현장영상 기반의 화면형태는 현재 사실적인 화면을 통해 현장감을 제공함으로써 사용자에게 가장 감성적으로 어필을 하고 있지만 이를 이상적으로 구현하기 위해서는 매우 정교한 패턴 매칭 방식 알고리즘이 요구되고, 서비스 지역이 사용자의 실제 위치 주변으로 제약되는 한계를 가진다. 본 논문에서는 미러월드의 도입을 통해 이러한 문제를 해결하는 위치 기반 서비스를 제안하고 시제품을 제작한다. 제안하는 서비스는 미러월드 데이터와 연계하여 매칭 알고리즘이나 사용자가 서비스 대상 지역에 있어야 하는 한계 없이 사용자에게 해당 지역을 사실적인 영상을 통해 현장감을 효과적으로 줄 수 있다.

Chemical Stability of Lithium Lanthanum Titanate (Li0.5La0.5TiO3) as a Solid Electrolyte for Lithium Secondary Batteries

  • 은영진;임완규;이원준
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.202.1-202.1
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    • 2014
  • 최근 대용량 에너지 저장장치로 사용하고자 하는 리튬-공기전지는 리튬 음극과 액체 전해질 사이의 화학적 불안정성이 문제가 되고 있다. 또한 리튬이온전지는 액체전해질의 사용으로 인해 폭발 등의 안정성 문제가 대두되고 있는 실정이다. 때문에 리튬-공기전지에서 리튬 음극을 액체 전해질로부터 보호할 수 있으며, 리튬이온전지의 액체전해질과 대체하였을 때 전극과도 안정한 고체전해질의 연구가 필요하다. 고체전해질은 구조적으로 crystalline, glassy, 폴리머로 나눌 수 있는데, 이 중 crystalline 구조의 고체전해질은 glassy 및 폴리머 고체전해질에 비해 상온에서 비교적 이온전도도가 높다고 알려져 있다 [1]. 그러나 이온전도도가 높은 황화물 및 질화물 고체전해질은 수분에 민감한 반면 [2,3], 산화물 계열의 물질은 안정할 것으로 예상된다. 본 연구에서는 이온전도도가 높은 산화물인 lithium lanthanum titanate ($Li_{0.5}La_{0.5}TiO_3$, LLTO)를 고체전해질로 선정하여 다양한 환경에서 화학적 안정성에 관해 연구하였다. LLTO와 각종 용액과의 화학적 안정성을 살펴보기 위해 고체전해질을 DI water, 1 M $LiPF_6$ Ethylene Carbonate (EC)-Dimethyl Carbonate (DMC) (50:50 vol.%), 0.57 M LiOH (pH=13), 0.1 M HCl (pH=1)에 immersion하고 무게, 표면형상, 상(phase), 이온전도도 등의 변화를 관찰하였다. 또한 LLTO와 전극간의 반응성을 알아보기 위해 LLTO 분말과 음극물질인 $Li_4Ti_5O_{12}$ 및 양극물질인 $LiCoO_2$ 분말을 혼합한 후 $300^{\circ}C{\sim}700^{\circ}C$의 온도범위에서 열처리하여 반응을 가속화 한 후 상변화 현상을 살펴보았다.

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트레드밀 훈련이 뇌졸중 환자의 보행, 균형 및 체간조절에 미치는 영향 (The effect of independent treadmill training on gait, balance and trunk control in a patient with chronic stroke)

  • 윤성익;천승철;이주상;정신호;이덕성;오덕원;심재훈;이규완
    • 대한물리치료과학회지
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    • 제13권2호
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    • pp.37-45
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    • 2006
  • The purpose of this study was to determine the effect of treadmill training on gait, balance, and trunk control in a patient with hemiparesis. A female subject who had suffered a left hemiparesis 12 months previously was selected for this study. A single subject ABA design was used. Eight data-collection sessions were conducted during each of three phases (baseline-intervention-withdrawal). During baseline and withdrawal phases, the treatment based on Bobath approach was performed for the subject, and during the intervention phase, treadmill walking training was added. Assessment tools were made using the 10 m walk test, Rivermead Visual Gait Assessment(RVGA), Berg Balance Scale(BBS), and a seated Lateral Reach Test(LRT). During the intervention phase, the time measured in 10 m walk test and the scores of RVGA and BBS were significantly improved, and the number of steps in 10 m walk test and LRT showed a small improvement. During withdrawal phase, the time measured in 10 m walk test and the scores of RVGA and BBS were shown the carry-over effect. This findings indicate that treadmill training has significant effect to gait function and balance in a patient with chronic hemiparesis.

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다용 한약처방 투여가 흰쥐의 신장기능에 미치는 영향 -십전대보탕, 보증익기탕, 오적산 및 육미지황탕을 중심으로- (Effects of High Frequency Herbal Medication Administrations on the Renal Functions in Rats -Focusing on Sipjeondaebotang, Bojunikgitang, Ojeoksan and Yukmijihwangtang-)

  • 신규원;이선동;박해모;전성진;변진석
    • 대한예방한의학회지
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    • 제9권1호
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    • pp.119-133
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    • 2005
  • Traditional herbal medicine is widely used among the Korean people, and other eastern Asian countries employ similar therapies as well. In recent years, due to increasing interest in herbal medicines, many researches have been made on the toxicity and side effects of herbal medications. Through private and public media, there have been many opinions suggesting taking herbal medicines is very harmful, especially on the liver and kidney functions. This assertion has been mainly presented by the doctors that practice western medicine, But this assertion is never based on adequate knowledge of herbal medicine. This study aims to provide the evidences that taking herbal medicines is safe on the renal functions. Four frequently used herbal medications(Sipjeondaebotang, Bojungigitang, Ojeoksan, and Yukmijihwangtang) were used to test the toxicity of herbal medicine oh the lab animal model(SD-Rat). There is no significant difference in body weight and kidney weight after herbal medication for 1 month. In all experimental groups, no abnormal findings were observed in histological study, and lab renal function index(BUN, creatinine, uric acid). These results say that four herbal multi-used-medicines, when medicated, is safe from the renal toxicity in lab animal model.

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만성 경통 환자의 치료에 있어서 능동적 경부 근육 훈련의 효과 (The Effect of Active Neck Muscle Training in the Treatment of Chronic Neck Pain)

  • 오덕원;심재훈;이규완;안창식;허진강;양영애
    • The Journal of Korean Physical Therapy
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    • 제16권4호
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    • pp.168-178
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    • 2004
  • The purposes of this paper were to investigate the effect of active treatment compared with a conservative treatment and to provide the information for physical therapy in patients suffering from chronic neck pain. Forty female subjects who were diagnosed with cervical radiculopathy participated in this study and were divided into the conservative and active treatment groups. The active treatment group consisted of 20 patients who were treated with therapeutic modalities and active neck exercise program during the admission (15 days) and one month after discharge. The conservative treatment group consisted of 20 patients who were not received with active neck exercise program. The assessment tools were made using visual analogue scale(VAS), neck disability index(NDI) and modified Zung depression scale(MZDS). All subjects were measured three times: before the admission, at discharge, and at one month after discharge. Data were compared by groups using independent t-test. VAS, NDI and MZDS scores measured at admission and discharge were not significantly different between the groups. On the assessment performed one month after discharge, VAS and NDI scores were significantly lower for the active treatment group compared with those of the conservative treatment group(p<0.05), but MZDS score was not significantly different between the groups. In the comparison of two treatment methods for chronic neck pain, active treatment was more effective than conservative treatment. The findings of the study indicate that active treatment in chronic neck pain has a positive effect in relieving pain and restoring neck function.

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좌골신경가동화기법이 만성 요통 환자의 통증과 슬관절 신전근력에 미치는 영향 (Effects of Sciatic Nerve Mobilization Technique on Perceived Pain and Knee Strength in Patient With Chronic Low Back Pain)

  • 차현규;오덕원
    • 한국전문물리치료학회지
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    • 제17권3호
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    • pp.31-39
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    • 2010
  • The purpose of this study was to determine the effect of sciatic nerve mobilization technique on perceived pain, straight leg raise test (SLR), and strength of knee extensor, location of symptoms (LOS) in patients with chronic low back pain. 22 patients with chronic low back pain were recruited for this study. The subjects were randomly assigned to either the experimental group (EG) or the control group (CG), with 11 patients in each group. All patients received a routine physical therapy (hot pack and transcutaneous electrical nerve stimulation). The mobilization technique of the sciatic nerve was performed for 10 min in the case of the EG subjects. Outcome measurements included the level of the perceived pain, SLR, and strength of the knee extensor, LOS. The measurements were recorded 3 times: before the intervention, after the intervention, and at 1 hour of follow up. The two groups did not significantly differ with regard to the level of perceived pain, SLR, and strength of the knee extensor, LOS before the test (p>.05). In the case of the EG subjects, all the variables measured after the intervention significantly differed from those measured before the intervention (p<.05). However, in the case of the CG subjects, a significant difference was noted only with regard to the level of perceived pain (p<.05). The findings indicate that sciatic nerve mobilization technique exerts a positive effect on the control of subjective symptoms and knee strength in patients with chronic low back pain. Further studies are required to generalize the result of this study.

폐콘크리트 미분말을 이용한 유해 폐기물 고화용 시멘트의 제조 (Fabrication of the Cement for the Solidification of the Toxic Waste using Waste Concrete Powder)

  • 김인섭;원종한;최광휘;최상흘;이종규;손진군;심광보
    • 한국세라믹학회지
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    • 제39권12호
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    • pp.1133-1137
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    • 2002
  • 폐콘크리트 미분말과 고로 슬래그를 사용하여 유해 산업폐기물 고화용 시멘트를 제조한 후 수화성상과 압축강도를 평가하고 이 시멘트를 COREX 슬러지에 첨가하여 고화처리 하였다. 폐콘크리트 미분말과 슬래그 미분말을 1:1로 하고 여기에 포틀랜드 시멘트와 반수석고를 각각 10% 첨가하여 만든 고화용 시멘트로 사용 가능한 강도를 발현하고 있었다. 이 시멘트로 COREX 슬러지를 고화한 경우에 7일에서 140 kgf/$cm^2$을 상회하는 강도를 보여 폐슬러지를 고화시켜 안정화하는데 응용할 수 있음을 확인하였다.

TiO2 Combining Spherical Activated Carbon Photocatalysts and Their Physicochemical and Photocatalytic Activity

  • Oh, Won-Chun;Kim, Jong-Gyu;Kim, Hyuk;Chen, Ming-Liang;Zhang, Feng-Jun;Zhang, Kan;Choi, Jong-Geun;Meng, Ze-Da
    • 한국재료학회지
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    • 제20권10호
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    • pp.535-542
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    • 2010
  • In this study, we used coal-based activated carbons and charcoal as startingmaterials, phenolic resin (PR) as a binder, and TOS as a titanium source to prepare $TiO_2$ combining spherical shaped activated carbon photocatalysts. The textural properties of the activated carbon photocatalysts (SACP) were characterized by specific surface area (BET), energy dispersive X-ray spectroscopy (XRD), scanning electron microscopy (SEM), iodine adsorption, strength intensity, and pressure drop. The photocatalytic activities of the SACPs were characterized by degradation of the organic dyes Methylene Blue (MB), Methylene Orange (MO), and Rhodamine B (Rh. B) and a chemical oxygen demand (COD) experiment. The surface properties are shown by SEM. The XRD patterns of the composites showed that the SACP composite contained a typical single, clear anatase phase. The EDX spectro for the elemental indentification showed the presence of C and O with Ti peaks. According to the results, the spherical activated carbon photocatalysts sample of AOP prepared with activated carbon formed the best spherical shape, a high BET surface area, iodine adsorption capability and strength value, and the lowest pressure drop, and the photocatalytic activity was better than samples prepared with charcoal. We compared the degradation effects among three kinds of dyes. MB solution degraded with the SACP is better than any other dye solutions.

IP 기반 비디오 서비스의 화질 측정을 위한 비참조 블록 열화 측정 방법 (No-reference Measurement of Blocking Artifacts to Assess the Quality of IP Based Video Service)

  • 이선오;민경연;심동규;이현우;류원;김진술
    • 대한전자공학회논문지SP
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    • 제46권6호
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    • pp.78-87
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    • 2009
  • 본 논문은 IP 기반 비디오 서비스의 화질 측정을 위하여 새로운 비참조 기반의 블록 열화 측정 알고리즘을 제안한다. 제안하는 방법은 IP 기반 비디오 서비스의 화질 측정을 위하여, 네트워크에 의한 블록 열화와 영상 압축에 의한 블록 열화를 구분한다. 또한 비참조 기반으로 블록 열화를 검출하기 위하여, 주변 블록과의 차와 비디오 수신 단말기의 오류 수정 알고리즘의 패턴을 이용하고, 열화된 블록의 세기와 분포를 이용하여 화질 저하 원인을 측정한다. 제안한 방법의 정확도를 확인하기 위하여, SSCQE 방법을 이용한 MOS 실험 결과와 제안한 방법을 이용하여 화질 측정한 결과를 비교하였다. 기존 알고리즘에 비하여 블록 열화 측정의 정확도가 1.3배의 성능 향상된 것을 확인할 수 있었다.

Quenching of Ofloxacin and Flumequine Fluorescence by Divalent Transition Metal Cations

  • Park, Hyoung-Ryun;Oh, Chu-Ha;Lee, Hyeong-Chul;Choi, Jae-Gyu;Jung, Beung-In;Bark, Ki-Min
    • Bulletin of the Korean Chemical Society
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    • 제27권12호
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    • pp.2002-2010
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    • 2006
  • This study examined the quenching of ofloxacin (OFL) and flumequine (FLU) fluorescence by $Cuj^{2+}$, $Ni^{2+}$, $Co^{2+}$ and $Mn^{2+}$ in an aqueous solution. The change in the fluorescence intensity and lifetime was measured at various temperatures as a function of the quencher concentration. According to the Stern-Volmer plots, the fluorescence emission was quenched by both collisions (dynamic quenching) and complex formation (static quenching) with the same quencher but the effect of static quenching was larger than that of dynamic quenching. Large static and dynamic quenching constants for both OFL and FLU support significant ion-dipole and orbital-orbital interactions between fluorophore and quencher. For both molecules, the static and dynamic quenching constants by $Cu^{2+}$ were the largest among all the metal quenchers examined in this study. In addition, both the static and dynamic quenching mechanisms by $Cu^{2+}$ were somewhat different from the quenching caused by other metals. Between $Ni^{2+}$ and FLU, a different form of chemical interaction was observed compared with the interaction by other metals. The change in the absorption spectra as a result of the addition of a quencher provided information on static quenching. With all these metals, the static quenching constant of FLU was larger than those of OFL. The fluorescence of OFL was quite insensitive to both the dynamic and static quenching compared with FLU. This property of OFL can be explained by the twisted intramolecular charge transfer in the excited state.