• Title/Summary/Keyword: MMI

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Characteristics of Damaging Earthquakes Occurred in Seoul Metropolitan Area for the Last Two Thousand Years (과거 2000년간 서울 및 수도권에서 발생한 피해 지진의 특성)

  • Kyung, Jai Bok
    • Journal of the Korean earth science society
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    • v.33 no.7
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    • pp.637-644
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    • 2012
  • The Seoul metropolitan area is densely populated with 40 percent of Korean people and quite weak to the seismic hazard. According to the analysis of historical documents, the largest earthquake occurred in this area is MMI VIII-IX acompanying with a large shaking, collapse of stone walls, collapse of houses, and many casualties. Two times of damaging earthquakes occurred in the first century (A.D. 27, 89), and there was a long quiet period of about 1430 years. Another big earthquakes re-occurred three times in the 16-17 century (1518, 1613, 1692) and then a quiet period has continued to the present time. Just after Seoul earthquake in 1518, aftershocks occurred almost 19 days consecutively and many triggered earthquakes occurred not only in Seoul metropolitan area but also in Hwanghae province, northern Korea. It indicates that the largest potential earthquake in and around Seoul is MMI VIII-IX with a long occurrence period of about 1400-1500 years.

Multimode interference coupled ring resonator using half ring and total internal reflection mirrors (반 링과 전반사 미러를 이용한 다중모드 간섭기로 결합된 링 공진기)

  • Kim, Doo-Gun;Choi, Young-Wan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.2
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    • pp.46-54
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    • 2007
  • We have fabricated and characterized MMI (Multimode Interference) coupled ring resonator with the total internal reflection mirrors and the semiconductor optical amplifier for the integration of the WDM (Wavelength Division Multiplexing) system. The TIR (Total Internal Reflection) mirrors were fabricated by self-aligned process and had losses of about 0.71 dB per mirror. Coupling in and out of a resonator was achieved using the extremely small MMI couplers. The MMI length and width used in the experiment were $119{\mu}m$ and $9{\mu}m$, respectively. The resulting FSR (Free Spectral Range) and on-off ratio were approximately 1.333 nm (162 GHz) and 13 dB, respectively.

Fabrication and Measurement of All-Optical Logic Device by Using Selective Area Growth Technology (선택영역성장 기술을 이용한 전광 논리소자용 광소자의 제작 및 측정)

  • Son, Chang-Wan;Yoon, Tae-Hoon;Lee, Seok;Nakano, Yoshiaki
    • Korean Journal of Optics and Photonics
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    • v.18 no.1
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    • pp.50-55
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    • 2007
  • Using the Selective Area Growth (SAG) technology of Metal Organic Chemical Vapor Deposition (MOCVD), we successfully integrated an active device and passive devices on the same substrate. In other words, we integrated a Semiconductor Optical Amplifier (SOA) as an active device and an S-bend waveguide and a Multi Mode Interference (MMI) waveguide as passive devices. The SOA is successfully integrated with passive devices on the same substrate. The Cross-Gain Modulation (XGM) characteristic of the integrated SOA and the loss of an MMI and an S-bend waveguide were measured. Measured XGM characteristics of the SOA showed an extinction ratio of 8.82 dB. The total loss of the MMI and S-bend waveguide was 18 dB.

A Study of the Autonomous Driving Path Planning for Concrete Pavement Cutting Operation (콘크리트 도로 표면절삭 작업을 위한 자율주행 진로계획 수립방안)

  • Moon, Sung-Woo;Seo, Jong-Won;Yang, Byong-Soo;Lee, Won-Sik
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.929-933
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    • 2007
  • Concrete Pavement Cutting Operation have Labor-intensive features. And Cutting Operation quality and productivity is influenced by operator's experience. Moreover Workers have risk of safety concerns. Therefore we need Concrete Pavement Cutting Operation automation system and system support software development on the economics. First of all we have to develop driving Path Planning for Concrete Pavement Cutting automation system. If result of Path Planning connect with automation system, Weak points is a complement to the existing Path Planning and we can obtain effective automation system. Consequently this paper suggest method of Autonomous Driving Path Planning for Concrete Pavement Cutting Operation And the Path Planning system application.

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Post-Harvest Traceability System of Grain (곡물의 수확후 이력관리시스템)

  • Lee, Hyo-Jae;Kim, Oui-Woong;Ahn, Jae-Whan;Han, Jae-Woong;Kim, Hoon
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.2
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    • pp.161-168
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    • 2018
  • In this study, IT based traceability system which is able to measure weight and moisture content of grain in the post-harvest process of intake, drying, storage and milling was developed in RPC(Rice processing complex). Measured information of weight, moisture content, yield, loss and quality was saved in the DB sever. Simultaneously, lot No. was generated and connecting to quality and traceability information. Also, automatic control system with MMI(Man Machine Interface) and yield and inventory control system(YICS) for grain was developed for the traceability system by applying the TCP/IP communication. In addition, simulation of system was performed for evaluation in RPC.

Advanced and Application of Onsite EEW Technology in Korea (국내에서의 지진현장경보 기술 고도화 및 적용)

  • Lee, Ho Jun;Jeon, Inchan;Seo, Jeong Beom;Lee, Jin Koo
    • Journal of the Society of Disaster Information
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    • v.16 no.4
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    • pp.670-681
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    • 2020
  • Purpose: This study aims to derive a PGV prediction equation and to enhance the application of the Onsite EEW technology which has developed through previous studies. Method: The prediction equation for the Onsite EEW derived from earthquake data M≥3.0 and MMI≥II over the past four years. Local seismic risk is estimated using M and PGV deduced from P wave properties. Result: The improved PGV prediction equation estimated the MMI with an average accuracy of 94.8% and the 𝜏c : Pd method also showed valid performance for alerting local seismic risks. Conclusion: Onsite EEW technology is successfully applied to Korea, and becomes to reduce the blind zone to about 14km.

Treadmill exercise enhances motor coordination and ameliorates Purkinje cell loss through inhibition on astrocyte activation in the cerebellum of methimazole-induced hypothyroidism rat pups

  • Shin, Mal-Soon;Kim, Bo-Kyun;Lee, Shin-Ho;Kim, Tae-Soo;Heo, Yu-Mi;Choi, Jun-Ho;Kim, Chang-Ju;Lim, Baek-Vin
    • Korean Journal of Exercise Nutrition
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    • v.16 no.2
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    • pp.73-84
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    • 2012
  • Thyroid hormones are important for the development of the brain including the cerebellum. In the present study, we investigated the effect of treadmill exercise on the survival of Purkinje neurons and the activation of astrocytes in the cerebellar vermis of hypothyroidism-induced rat pups. On the day of perinatal 14, pregnant rats were divided into two groups (n = 5 in each group): the pregnant control group and the pregnantmethimazole (MMI)-treated group. For the induction of hypothyroidism in the rat pups, MMI was added to the drinking water (0.02% wt/vol), from the day of perinatal 14 to postnatal 49. After delivery, male rat pups born from the pregnant control group were assigned to the control group. Male rat pups born from the MMI-treated group were divided into the hypothyroidism-induction group, the hypothyroidism-induction with treadmill exercise group, and the hypothyroidism-induction with thyroxine (T4) treatment group (n = 10 in each group). The rat pups in the exercise group were forced to run on a treadmill for 30 min once a day for 4 weeks, starting on postnatal day 22. In the hypothyroidism-induced rat pups, motor coordination was reduced and Purkinje cell death and reactive astrocytes in the cerebellar vermis were increased. Treadmill exercise enhanced motor coordination, increased the survival of Purkinje neurons, down-regulated reactive astrocytes, and enhanced brain-derived neurotrophic factor (BDNF) and receptor tyrosine kinase B (TrkB) expressions in the hypothyroidism-induced rat pups. These results suggest that treadmill exercise has beneficial effects in terms of protecting against thyroid dysfunction by increasing T3 and T4 and the related protein, BDNF, as well as TrkB, inhibition on astrocyte activation and the reduction of Purkinje cell loss regarding the cerebellum in hypothyroidism rat pups.

Performance Evaluation of the Tumor Tracking Method Using Beam on/off Interface for the Treatment of Irregular Breathing (호흡이 불규칙한 환자의 치료를 위한 Beam on/off Interface를 이용한 종양 추적 치료 방법의 성능 평가)

  • Lee, Minsik
    • Journal of the Korean Society of Radiology
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    • v.12 no.3
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    • pp.343-349
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    • 2018
  • Dose rate regulated tracking is known to be an efficient method which adaptively delivers tracking treatments when patient breathing is irregular. The Motion Management Interface (MMI, Varian Medical System, CA), which provides beam on/off switching during treatment is available for clinic. Study is to test if delivering the adaptive tumor tracking is feasible for irregular breathing using beam switching with MMI. 55 free breathing RPM traces acquired from lung cancer patients are used. The first day RPM traces of the patients are utilized to design preprogrammed tracking MLC patterns, of which periods are intentionally reduced by 20% in order to catch up the variation of patient breathing irregularity in the treatment day. Eligibility criteria for this technique are the variation of amplitude and period less than 20%. An algorithm which determines beam on/off every 100 ms by considering the preprogrammed (MLC) positions and current breathing positions is developed. Tracking error and delivery efficacy are calculated by simulating the beam-switching adaptive tracking from the RPM traces. Breathing patterns of 38 patients (70%) met the eligibility criteria. Tracking errors of all of the cases who meet the criteria are less than 2 mm (average 1.4 mm) and the average delivery efficacy was 71%. Those of rest of the cases are 1.9 mm and 48%. Adaptive tracking with beam switching is feasible if patient selection is based on the eligibility criteria.