• Title/Summary/Keyword: Loss and damage

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The Noise Level Assessment of Dental Equipment (치과 의료장비의 소음 수준 평가)

  • Lee, Jeong-Suk;Han, Ye-Seul;Cho, Young-Sik
    • Journal of dental hygiene science
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    • v.15 no.5
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    • pp.603-611
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    • 2015
  • This research is aimed at cutting off hearing loss and other harmful factors due to noise and providing basic material for noise reduction plan. As the research method, this research assessed noise by measuring acoustic pressure level and frequency in various situation of non-treatment and treatment. As the measurement result, average noise degree of high speed handpiece of non-treatment, ultrasonic waves scaler, and low speed handpiece showed 58~66 dB(A). Average noise degree of scaling of treatment, tooth elimination, and denture adjust showed 73~81 dB(A). The result is inferior to recognized standards of noise induced hearing loss. But the result of assessing this with (noise rating) NR curve was NR-73~78, which exceeded general workplace noise standard. This level can cause hearing loss when exposed to a long time. Therefore, treatment office noise during dental treatment can cause psychological and physical damage in dental clinic employees, and it is urgently required to establish systematic and active noise reduction plan.

Evaluation of Deterioration of Larix kaempferi Wood Heat-treated by Superheated Steam through Field Decay Test for 12 Months (12개월 야외 내후성 시험에 의한 과열증기 열처리된 낙엽송재의 열화 평가)

  • Park, Yonggun;Han, Yeonjung;Park, Jun-Ho;Chung, Hyunwoo;Kim, Hyunbin;Yang, Sang-Yun;Chang, Yoon-Seong;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.5
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    • pp.497-510
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    • 2018
  • In this study, the decay resistance of larch wood, which was heat treated by superheated steam, was evaluated by the field decay test. During the field decay test of 12 months, non-treated wood has been severely damaged by termite, however, no visible damage has occurred in the preservative-treated wood and superheated steam heat-treated wood. Results of field decay test showed approximately 5% mass loss of the non-treated wood and the preservative-treated wood, and approximately 1% mass loss of the superheated steam heat-treated wood. After the field decay test for 12 months, the residual amount of preservatives remaining in the preservative-treated wood was lower than that before the field decay test. It was considered that the preservative was partially eluted during the field decay test, and the mass loss of the preservative-treated wood was thought to be similar to that of the non-treated wood. Through this study and additional long-term monitoring test, superheated steam heat treatment can be considered to be an environmental-friendly method to enhance the decay resistance of wood against rot fungi and/or insect without chemical treatment such as preservative injection.

Design of quench detector for protection of HTS cable (고온 초전도 케이블의 퀜치 보호를 위한 검출기 설계)

  • Choi, Yong-Sun;Hwang, Si-Dole;Yim, Seong-Woo;Choi, Hyo-Sang;Hyun, Ok-Bea
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.958-960
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    • 2002
  • High Temperature Superconducting (HTS) devices make it possible to operate with no electrical loss by resistance. If, however, the applied current is over its critical current, the phase of HTS devices is changed to normal state, so called, quench. In this case, since resistance of HTS is increased abruptly, it can not be avoidable to damage the whole apparatus. In this study, quench detector to protect HTS devices was proposed. We designed the quench detecting circuit and tested the performance of the circuit. The detecting circuit was consisted of Op-Amp and low pass filter etc, to detect very low voltage around $1{\mu}V$. The circuit detected effectively the low voltage when over current is applied to HTS tapes. At the next step, we are going to apply and test the circuit to protect the prototype HTS cable.

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Resin bonded fixed prosthesis for single tooth restoration: A case report (단일치 상실을 레진 접착 고정성 보철물로 수복한 증례)

  • Kim, Eunkyung;Lee, Jonghyuk
    • The Journal of Korean Academy of Prosthodontics
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    • v.55 no.3
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    • pp.325-330
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    • 2017
  • In the case of single tooth replacement, a fixed prosthesis or a dental implant is the treatment option commonly selected as first choice. However, any amount of sound tooth structure should be removed to prepare the abutment teeth for full coverage retainer. The adjacent tooth damage can be avoided placing a dental implant. However, depending on the patient's oral condition and any other circumstances, it may be impossible or delayed. In this case resin bonded fixed partial denture was selected as an alternative that can restore single tooth loss without much tooth structure removal to the young patients and the patients with gingival recession. We report these patients were satisfied with esthetic and function.

The Reason for the Loss of Photosynthetic Activity in Isolated Spinach Chloroplasts during Photosynthesis (분리된 시금치 엽록체에서 광합성중 광합성능이 소실되는 이유)

  • 김성수
    • Journal of Plant Biology
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    • v.36 no.4
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    • pp.371-375
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    • 1993
  • $ CO_2$ fixation of isolated intact spinach chloroplasts under saturating light began to decrease after 20 min, and stopped completely after 1 h. To identify the lesion sites for the die off, reconstituted chloroplast system was used with chloroplasts collected at several phases of time course. $ CO_2$ fixation was inhibited in the reconstituted chloroplasts made of thylakoids and stroma in the later phases, but showed a higher degree of inhibition by the participation of thylakoids than that of stroma in the later phases. Measurement of photophosphrylation and NADP reduction revealed that a severed thylakoidal damage was occurred at the later phases. This results indicate that the lesion sites for the die off are in the thylakoid.the thylakoid.

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A simulative method for evaluating the resistance of the flight deck's operational capability to the attack of anti-ship weapons

  • Yang, Fangqing;Wang, Chao;Liao, Quanmi;Huang, Sheng
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.6
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    • pp.563-576
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    • 2016
  • The flight deck of an aircraft carrier is relatively vulnerable compared to its hull, as the damage of some subsystems on the flight deck may cause the carrier losing its operational capability. Therefore, this work aims to represent a simulative method for evaluating the resistance of the flight deck's operational capability in the condition that the aircraft carrier is together with its strike group and the enemy uses the anti-ship missiles with the cluster warheads to attack. In the simulations, the susceptibility of the carrier and the vulnerability of the aircraft guarantee resources are gained. Then, with the help of the closed queuing network, the residual sortie generation rate can be solved, which reflects the flight deck's residual operational capability. The results have proven that the flight deck is of strong resistance to these attacks while it is very sensitive to the loss of some key aircraft guarantee resources.

Full mouth rehabilitation with extremely worn dentition (심한 치아 마모 환자의 전악보철 수복 증례)

  • Cha, Hwa-Ryun;Yeom, Kyeong-Yeon;Lee, Yong-Sang;Kim, Na-Hong
    • Journal of Dental Rehabilitation and Applied Science
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    • v.33 no.3
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    • pp.238-244
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    • 2017
  • Pathologic attrition leads to pathologic damage on occlusal plane, functional disorders, occlusal disharmony, esthetic problems, pulpal lesion, temporomandibular joint (TMJ) disorder. In this case, treatment plan should be considered for possibility of vertical dimension loss, occlusal pattern, esthetics, phonetics, amount of vertical dimension increase. This case report was a 71-year-old man who had severely worn dentition. Full mouth rehabilitation was carried out with vertical dimension increase due to limited space for prosthesis. After evaluation of provisional restorations for patient's compliance, final restorations were fabricated and routine clinical assessments were made. This case presents that a satisfactory clinical result was achieved by restoring the worn dentition.

A Study on the Diversity of Shanghan(傷寒) Concept in Gangpyeong-Sanghanlun(康平傷寒論) (『강평상한론(康平傷寒論)』 내 '상한(傷寒)' 개념의 다양성에 대한 고찰)

  • Lee, Soong-In;Jeong, Jong-Kil
    • Journal of Korean Medical classics
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    • v.28 no.1
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    • pp.97-110
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    • 2015
  • Objectives : Usually medical terminology of oriental mecidine has a multiple meaning. But concept of Shanghan(傷寒) should be simple, because Shanghanlun(傷寒論) is a clinical guideline book. So I researched to suggest many concept of Shanghan, which are suitable for each chapter of Shanghanlun. Methods : I enumerated provisions including Shnaghan from the original texts of Gangpyeong-Shanghanlun(康平傷寒論). And I translated and reviewed them. Results : 1. Shanghan of Preface(序文) means a disease of high fatality. 2. Shanghan of Shanghanrye(傷寒例) means diseases due to physical damage of cold weather. 3. Shanghan of Diagnosis of Daeyang Disease(辨大陽病) - Neck stiffness(痙), Dampness(濕), Sun stroke(暍) means certain disease names accompanying fever, chill. 4. Shanghan used in Diagnosis of Diseases is a premise of many provisions of Shanghanlun. And Shanghan is made up of finished fever, expected fever, chill, body pain, loss of appetite, image of tension. Conclusions : We can use a appropriate translation on Shanghan of each chapter of Gangpyeong-Sanghanlun. Especially Shanghan used in "Diagnosis of Diseases" should have more accurate meaning.

A Case study on the plan for the ESC integrating optimized train operation system for Fire & power failure accident in subway (도시철도 화재$\cdot$단전시 최적 열차운행을 위한 통합운영체계 구축방안에 관한 연구)

  • Kim Young-Wook;Choi Se-Wan;Kim Young-Kyu
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1185-1192
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    • 2004
  • Recently heavy traffic is getting worse because increasing population of transportation in urban area. In order to solve this problem. subway is realized with high speed, high density, highly efficiency. When fire accident happened in Dae-Gu subway in February 2003, there happened loss of people and lots of damage because of not being able to control even though fire alarm which was set up in the station rang. This thesis has constructed a simulation integrating operation system using a Database construction, operating program analysis in order to build up the most efficient train operation system. The result of simulation integrating operation system with emergency virtual situation like station and train fire, train failure, power line failure, all trains running on the rail were secured safety by train operation control system. With integrating operation of each train control system, train system, power system, machine facility system, the most efficient integrating operation system should have been constructed at the time the subway fire and power failure broke out.

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Design of a 170 GHz Notch Filter for the KSTAR ECE Imaging Sensor Application

  • Mohyuddin, Wahab;Woo, Dong Sik;Kim, Sung Kyun;Kim, Kang Wook;Choi, Hyun-Chul
    • Journal of Sensor Science and Technology
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    • v.25 no.1
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    • pp.8-12
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    • 2016
  • A planar, light-weight, and low-cost notch filter structure is required for the KSTAR ECEI (Electron Cyclotron Emission Imaging) system to protect the mixer arrays from spurious plasma heating power. Without protection, this heating power can significantly degrade or damage the performance of the mixer array. To protect mixer arrays, a frequency selective surface (FSS) structure is the suitable choice as a notch filter to reject the spurious heating power. The FSS notch filter should be located between the lenses of the ECEI system. This paper presents a 170 GHz FSS notch filter for the KSTAR ECEI sensor application. The design of such an FSS notch filter is based on the single-sided square loop geometry, because that makes it relatively insensitive to the incident angle of incoming wave. The FSS notch filter exhibits high notch rejection with low pass-band insertion loss over a wide range of incident angles. This paper also reviews the simulated and measured results. The proposed FSS notch filter might be implemented in other millimeter-wave plasma devices.