• 제목/요약/키워드: MMO

Search Result 103, Processing Time 0.024 seconds

Embeddable reference sensors for corrosion monitoring in concrete structures (콘크리트 구조물의 부식감시용 매설형 기준전극의 전기화학적 안정성에 관한 연구)

  • Ha, Tae-Hyun;Bae, Jeong-Hyo;Ha, Yoon-Cheol;Lee, Hyun-Goo;Kim, Dae-Kyeong
    • Proceedings of the KIEE Conference
    • /
    • 2005.11a
    • /
    • pp.160-163
    • /
    • 2005
  • Several sensors are involved in the cor개sion monitoring of concrete structures. This paper deals with the monitoring of concrete structures by embeddable reference sensors. $MnO_2$, MMO and graphite reference sensors are fabricated in the laboratory as suitable as embeddable type into the concrete structures. Sensors are embedded into the mortars and the performance was studied in the absence and presence of chloride ions. The electrochemical stability of the sensors was carried out for the exposure period of one year. Polarisation behaviour and impedance of the sensors in mortar was carried out in three aqueous solutions namely distilled water, 3% NaCl and natural sea water.

  • PDF

알칼리 수산화물에서 핵연료피복관용 Zr합금의 부식거동

  • 정용환
    • Proceedings of the Korean Nuclear Society Conference
    • /
    • 1995.05a
    • /
    • pp.759-764
    • /
    • 1995
  • 여러 가지 Zr합금의 부식거동을 LiOH, NaOH, KOH, RbOH, CsOH 용액조건에서 autoclave를 이용하여 조사하였다. 용액내의 알칼리 농도는 0.3mmol 4.3mmol 31.5mmo1를 선택하였는데, 이는 Li의 경우에 2.2ppm 30ppm, 220ppm에 해당되는 농도이다. Zr합금은 ZrSn-TRM(천이원소)과 ZrSnNb-TRM(천이원소)의 두 종류의 합금을 사용하였다. 알칼리 분위기에서 Zr함금의 부식을 지배하는 이온은 양이 온인 것으로 밝혀졌으며, 양이온의 반경이 Zr합금의 천이전 영역에서의 부식을 지배하는 것으로 나타났다. Nb첨가 합금은 Zircaloy형 합금보다 내식성이 떨어진다. LiOH가 부식을 가장 가속시키는 알칼리로 밝혀졌으며 CsOH나 KOH는 거의 Zr합금의 부식을 가속시키지 않는다. 따라서 CsOH나 KOH는 PWR에 적응 가능한 대체 알칼리로서 가능성을 보였다.

  • PDF

MVNO Regulations for Fixed Network Operators (유선사업자의 MVNO 시장진입 사례와 규제방안)

  • Kim, B.W.
    • Electronics and Telecommunications Trends
    • /
    • v.18 no.1 s.79
    • /
    • pp.75-84
    • /
    • 2003
  • 최근 국내에서도 이동망 경쟁활성화를 위한 방안으로서 MVNO 규제제도를 도입해야 한다는 논의가 진행되고 있다. 이미 주요 선진국들은 이동통신망의 경쟁활성화, 유무선통합의 추진, 이동통신네트워크 여유용량 해소, 모바일 인터넷의 활성화를 위해 다소 입장의 차이는 있지만 MVNO 규제제도를 일반적으로 도입하는 추세이다. 또한, 새로운 MVNO 규제제도 하에서 다양한 신규사업자들이 이동통신시장에 진입하고 있다. 지난 2002년 10월 1일에는 영국의 유선사업자인 BT가 자회사인 MMO2를 MNO로 하여 MVNO시장에 진입하여 이동통신 이용자들을 대상으로 서비스를 개시하였다. 국내에서도 MVNO 제도가 도입될경우 BT와 같은 유선사업자들이 시장에 진입할 수 있을 것으로 사료된다. 따라서 본 고에서는 국내의 유선사업자들이 MVNO로서 국내 이동통신시장에 진입할 수 있는 제도적 방안을 검토하였다.

Adaptive Robust Output Tracking for Nonlinear MMO Systems

  • Im, Kyu-Mann
    • Proceedings of the Korea Institute of Convergence Signal Processing
    • /
    • 2003.06a
    • /
    • pp.177-182
    • /
    • 2003
  • The robust output tracking control problem of general nonlinear MIMO systems is discussed. The robustness against parameter uncertainties is considered. In this paper, we proposed the robust output tracking control scheme for a class of MIMO nonlinear dynamical systems using output feedback linearization method. The presented control scheme is based on the VSS. We assume that the nonlinear dynamical system is minimum phase, the relative degree of the system is r$_{1}$+r$_{2}$+…r$_{m}$$\leq$ n and zero dynamics is stable. It is shown that the outputs of the closed-loop system asymptotically track given output trajectories despite the uncertainties while maintaining the boundedness of all signals inside the loop. And we verified that the proposed control scheme is then applied to the control of a two degree of freedom (DOF) robotic manipulator with payload.d.

  • PDF

Quantum rebound attacks on reduced-round ARIA-based hash functions

  • Seungjun Baek;Jongsung Kim
    • ETRI Journal
    • /
    • v.45 no.3
    • /
    • pp.365-378
    • /
    • 2023
  • ARIA is a block cipher proposed by Kwon et al. at ICISC 2003 that is widely used as the national standard block cipher in the Republic of Korea. Herein, we identify some flaws in the quantum rebound attack on seven-round ARIA-DM proposed by Dou et al. and reveal that the limit of this attack is up to five rounds. Our revised attack applies to not only ARIA-DM but also ARIA-MMO and ARIA-MP among the PGV models, and it is valid for all ARIA key lengths. Furthermore, we present dedicated quantum rebound attacks on seven-round ARIA-Hirose and ARIA-MJH for the first time. These attacks are only valid for the 256-bit key length of ARIA because they are constructed using the degrees of freedom in the key schedule. All our attacks are faster than the generic quantum attack in the cost metric of the time-space tradeoff.

The Protective Effects of Ethanol Extract of Wild Simulated Ginseng on Carbon Tetrachloride Induced Acute Hepatic Injury in Mouse (사염화탄소 유발 급성 간독성 생쥐모델에서 산양삼 에탄올 추출물의 간 보호 효과)

  • Lee, Soo-Min;Park, Sun-Young;Jang, Gi-Seuk;Ly, Sun-Yung
    • Journal of Nutrition and Health
    • /
    • v.41 no.8
    • /
    • pp.701-710
    • /
    • 2008
  • The wild simulated ginseng (WSG) has been effectively used in folk medicine as a remedy against hepatic disease, hypertension and arthritic disease. However, there is still lack of scientific proof about its antioxidant capability. The present study has been conducted to evaluate the protective role of the WSG ethanol extract in the CCl4-induced oxidative stress and resultant hepatic disfunction in ICR mice. The electron donating abilities and IC50 of WSG etnanol extract were 76.86 ${\pm}$ 1.06% and 33.3 ${\mu}g$/mL (that of ascobic acid was 16.5 ${\mu}g$/mL), respectively. Total antioxidant status of WSG extract was 2.13 ${\pm}$ 0.06 mmoL/mg, while the values of ascorbic acid and BHT were 3.63 ${\pm}$ 0.06 and 3.12 ${\pm}$ 0.02, respectively. ICR mice (aged 3weeks) were fed for 4 weeks on AIN-93M diet and had free access to food and water. The animals were divided into three groups: normal group (intraperitoneally (i.p) injected with PBS at 100 ${\mu}L$/mouse), group C; CCl4-induced and without any treatment. (i.p injected only PBS, 100 ${\mu}L$ /mice), group G; CCl4-induced and treated with WSG (i.p injected with 5 mg WSG extract per mouse, suspended in 100 ${\mu}L$ phosphate buffer). After the i.p. injection of WSG or PBS (5 times for 7weeks), all mice were administered CCl4 in olive oil at the last day of the experiment, except for normal group. The normal group was administered only olive oil. Determination of plasma triglyceride, total cholersterol, fasting glucose and GPT activity was performed using automatic blood analyzer. To evaluate the protective effect against the oxidative stress, DNA fragmentation and TBARS were determined in blood leucocytes and RBC and hepatocyte, respectively. Body and organs weights and food intake did not show significant differences among the groups. Blood total cholesterol of group G was similar to that of normal group, which was the lowest in group C. The fasting blood glucose level was the highest in normal group (205.20 ${\pm}$ 135.24), which were decreased in group C (134.2 ${\pm}$ 79.31) and group G (126.48 ${\pm}$ 77.05). TBARS values in a red blood cell and hepatic tisuue homogenate were lower in group G comparing to the group C. DNA% in tail, tail length (TL) and tail moment (TM) of blood leucoocytes showed the highest values in group C (20.11 ${\pm}$ 2.47, 17.36 ${\pm}$ 2.58, 94.11 ${\pm}$ 12.29) and they were significantly diminished in group G (9.63 ${\pm}$ 1.19, 7.04 ${\pm}$ 1.50, 38.64 ${\pm}$ 7.60). In conclusion, wild simulated ginseng might be a protective agent against the oxidative stress.

Characteristics of Methanol Production Derived from Methane Oxidation by Inhibiting Methanol Dehydrogenase (메탄올탈수소효소 저해시 메탄산화에 의한 메탄올 전환생성 특성)

  • Yoo, Yeon-Sun;Han, Ji-Sun;Ahn, Chang-Min;Min, Dong-Hee;Mo, Woo-Jong;Yoon, Soon-Uk;Lee, Jong-Gyu;Lee, Jong-Yeon;Kim, Chang-Gyun
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.33 no.9
    • /
    • pp.662-669
    • /
    • 2011
  • This study was conducted to biologically convert methane into methanol. Methane contained in biogas was bio-catalytically oxidized by methane monooxygenase (MMO) of methanotrophs, while methanol conversion was observed by inhibiting methanol dehydrogenase (MDH) using MDH activity inhibitors such as phosphate, NaCl, $NH_4Cl$, and EDTA. The degree of methane oxidation by methanotrophs was the most highly accomplished as 0.56 mmol for the condition at $35^{\circ}C$ and pH 7 under 0.4 (v/v%) of biogas ($CH_4$ 50%, $CO_2$ 50%) / Air ratio. By the inhibition of 40 mM of phosphate, 50 mM of NaCl, 40 mM of $NH_4Cl$ and $150{\mu}m$ of EDTA, methane oxidation rate could achieve more than 80% regardless of type of inhibitors. In the meantime, addition of 40 mM of phosphate, 100 mM of NaCl, 40 mM of $NH_4Cl$ and $50{\mu}m$ of EDTA each led to generating the highest amount of methanol, i.e, 0.71, 0.60, 0.66, and 0.66 mmol when 1.3, 0.67, 0.74, and 1.3 mmol of methane was each concurrently consumed. At that time, methanol conversion rate was 54.7, 89.9, 89.6, and 47.8% respectively, and maximum methanol production rate was $7.4{\mu}mol/mg{\cdot}h$. From this, it was decided that the methanol production could be maximized as 89.9% when MDH activity was specifically inhibited into the typical level of 35% for the inhibitor of concern.

Correlation Among the Cervical Kyphotic Angle, Pain, and Disability Level in Patients With Temporomandibular Disorders (턱관절장애 환자의 목뼈 뒤굽음 각과 통증 및 기능장애 수준 간에 상관성 연구)

  • Lee, In-su;Kim, Suhn-yeop
    • Physical Therapy Korea
    • /
    • v.27 no.2
    • /
    • pp.102-110
    • /
    • 2020
  • Background: There is an opinion that improper postures of the head and cervical spine are associated with temporomandibular joint (TMJ) disorders (TMDs). Objects: The aim of this study was to investigate the proportions among the cervical kyphotic angle, physical symptoms including the pain intensity level of the TMJ, and severity of TMD disability in patients diagnosed with TMD. Methods: Sixty-two subjects participated in the study. The evaluation tools included measurements of the cervical kyphotic angle based on the Ishihara index, pressure pain threshold (PPT) on the TMJ, maximal mouth opening (MMO) without pain, current pain intensity level of the TMJ measured using the Quadruple Visual Analogue Scale (QVAS), Korean TMD (KTMD) disability index, KTMD Symptom Frequency/Intensity Scales (SFS/SIS), and Korean Headache Impact Test-6. Correlation analysis was conducted to investigate the correlations between the cervical kyphotic angle and parameters related to TMJ symptoms. Results: Variables that were significantly correlated with the cervical kyphotic angle were the PPT around the TMJ (r = 0.259, p < 0.05), current pain intensity level of the TMJ based on the QVAS (r = -0.601, p< 0.01), and usual pain intensity level based on the SIS (r = -0.379, p < 0.01). The level of TMD functional disability was significantly correlated with the degree of headache (r = 0.551, p < 0.01), level of PPT of the TMJ (r = -0.383, p < 0.01), pain-free MMO (r = -0.515, p < 0.01), pain intensity level of the TMJ based on the QVAS (r = 0.393, p < 0.01), TMD symptom frequency (r = 0.739, p < 0.01), usual pain intensity of the TMJ (r = 0.624, p < 0.01), and most severe pain intensity of the TMJ (r = 0.757, p < 0.01). Conclusion: There is a positive correlation between the cervical kyphotic angle and PPT and a negative correlation between the current and usual pain intensity levels of the TMJ. The cervical kyphotic angle was a predictor of the pain level, tenderness threshold, and intensity of pain in the TMJ.

The Effect of Postural Yinyang Correction of Temporomandibular Joint for Temporomandibular Disorder

  • Lee, Seung-Jeong;Ryu, Hye-Min;Kim, Su-Gyeong;Park, Eun-Jin;Lim, Jae-Eun;Lee, Young-Jun;Song, Choon-Ho;Yoon, Hyun-Min;Kim, Cheol-Hong
    • Journal of Acupuncture Research
    • /
    • v.35 no.3
    • /
    • pp.129-137
    • /
    • 2018
  • Background: The purpose of this study was to determine the effect of Postural Yinyang correction of the temporomandibular joint (functional cerebrospinal therapy) on temporomandibular disorder. Methods: Medical records of 21 outpatients were reviewed who were diagnosed with temporomandibular joint disorder, unspecified (K0769) and treated at the Department of Acupuncture & Moxibustion, Dong-Eui University Korean Medicine Hospital from May $1^{st}$, 2017 to April $30^{th}$, 2018. Patients received more than 10 treatments of upper cervical manipulation and performed self-exercise therapy more than 3 times a day and wore an accurate balancing appliance in the oral cavity for more than 8 hours per day. To estimate the efficacy, visual analogue scale (VAS), numerical rating scale (NRS), maximum mouth opening (MMO), symptom intensity scale (SIS), max SIS (MSIS), symptom frequency scale (SFS), mandibular function impairment questionnaire (MFIQ) and 5-point Likert scale were used. Results: NRS and MSIS were significantly improved during each period. VAS, MMO, SIS, and SFS were significantly improved during each period, except the period from the $8^{th}$ to $10^{th}$ visit. MFIQ score was significantly improved during the period from the $1^{st}$ to $10^{th}$ visit. In the 5-point Likert scale, the results showed a high patient satisfaction with the treatment. Conclusion: These results showed that functional cerebrospinal therapy using an accurate balancing appliance, may be useful for reducing the symptoms of temporomandibular disorder.