部員의 海技能力 開發과 그 履行에 관한 考察

정대율(Dae-Yul Chong),전영우(Yeong-Woo Jeon) 한국해사법학회 2007 해사법연구 Vol.19 No.1

  2006년 해사노동협약은 2006년 2월 23일 제네바에서 개최된 국제노동기구(ILO)의 제94차 국제노동총회에서 채택되었다. 이 협약의 채택과정에서 ILO는 선박조리사를 제외한 선원의 훈련 및 자격증명에 관한 요건과 ILO 제74호 유능부원의 자격증명에 관한 사항은 국제해사기구(IMO)에 이관하여 규정하기로 하였다. 이에 따라 IMO STW 전문위원회는 제36차에서 제38차 회의까지 부원의 해기능력을 검토하고 개발을 완료하였다.<BR>  이 논문은 IMO에서 개발한 유능부원의 해기능력의 내용을 소개하고, 국내법에 수용하기 위한 방향을 제시하는 것을 목적으로 한다.   “Maritime Labour Convention, 2006" was adopted by the General Conference of the International Labour Organization(ILO) at its ninety-fourth session in Geneva on 23 February, 2006. In considering the provisions of seafarer"s training and qualifications in the Maritime Labour Convention, ILO agreed that the training and certification requirements for seafarer, excluding the ship"s cook, and the principles of the ILO Convention on Certification of Able Seamen, 1946(No. 74) were to be transferred to the International Maritime Organization(IMO).<BR>  The IMO STW Sub-committee elaborated and completed the development of competences for ratings from 36 to 38 sessions.<BR>  This study aims to introduce the developed competences for ratings(able seafarer) and to provide a proposal of implementing them in the domestic law.

The Feasibility Study of Noise Disturbance in STW Process

Arjin Numsomran,Sean Niyomsuk,Vittaya Tipsuwanporn 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

Because the problem of 9020 error code occurrence in STW process that effect to the time and resource in production process, the feasibility study of noise disturbance in STW project has been created and has the purpose of analysis and determination of 9020 error code occurrence and find the suitable method the solve the problem. This paper presents the feasibility study of noise disturbance in STW process. In this paper we studied STW process and its problem, analyzed noise disturbance in STW process, hypothesized the improvement method, did the experiment for determining the frequency and amplitude of Noise Disturbance and did the experiment for improvement methods. The results from experiment will be the advantage for implementation of system improvement that can decrease the effect of 9020 error code occurrence in STW process.

Interfacial strengthening between graphene and polymer through Stone-Thrower-Wales defects: <i>Ab initio</i> and molecular dynamics simulations

Moon, Janghyuk,Yang, Seunghwa,Cho, Maenghyo Elsevier 2017 Carbon Vol.118 No.-

<P>In this study, we revealed the interfacial strengthening mechanism between a Stone-Thrower-Wales (STW) defective single layer graphene and polypropylene (PP), through a density functional theory (DFT) simulation and atomistic molecular dynamics simulations. In quantum mechanical simulation, the adhesion energy of propylene monomer on STW defective graphene is calculated with van der Waals interaction. An improved adsorption characteristic of propylene to the STW defective graphene is clearly observed, compared with a pristine counterpart. For deeper understanding of the adsorption, the electronic structure calculation and geometrical analysis of the adsorbed structures are also performed. In molecular dynamics simulation, three transversely isotropic nanocomposite unit cell structures consisting of PP and single layer graphene having a different number of STW defects are constructed. The stress-strain curves of nanocomposites according to the density of STW defects are obtained from uniaxial tension and shear tests. Since the properties of graphene itself are degraded by the STW defects, the overall stress-strain characteristics of nanocomposites involving the deformation of graphene are degraded by the addressed STW defects. However, in longitudinal shearing, where interfacial shearing between graphene and PP is involved, the STW defect can critically improve the shear load bearing capability. The increased interfacial shear load transfer is mostly attributed to the rippling of graphene at the STW defective sites, and the resultant surface roughness of graphene. (C) 2017 Elsevier Ltd. All rights reserved.</P>

國際海事協約의 持續的 强化의 問題點과 그 解決 必要性에 관한 硏究

全永遇(Yeong-Woo Jeon) 한국해사법학회 2008 해사법연구 Vol.20 No.1

  이 논문은 국제해사협약의 강행규정의 이행주체인 선원의 업무부담을 파악하고 이들에게 부과된 의무를 현장에서 효율적으로 이행할 수 있는지 분석하여 그 개선방향을 모색하는 것을 목적으로 한다. 그 방법론으로서 강행협약의 이행과 관련된 선원의 의무사항 개요 식별, 동 사안과 관련하여 제38차 선원 훈련ㆍ당직 전문위원회에 제출된 문서의 분석 그리고 최근 도입된 강행규정의 이행으로 인한 선내업무부담에 대한 선원 및 회사 담당자의 인식을 파악하기 위한 설문조사ㆍ분석을 실시하였다.<BR>  설문분석 결과 도출된 내용은 다음과 같다. 첫째, ISM Code의 내용과 안전관리시스템에 대한 이해정도와 관련하여 ISM 코드 등에 대한 지식은 폭넓게 확산되어 있었고, 가장 최근에 승선한 선박에서의 안전관리 매뉴얼 시행 정도는 선원집단과 육상의 ISM 책임자 집단의 압도적 다수가 안전관리 매뉴얼의 시행 수준을 보통이상으로 응답하여 ISM 활동은 동 코드의 도입 이후 그 시행수준이 크게 향상된 것으로 나타났다.<BR>  둘째, 선내 업무부담과 관련하여 ① ISM 활동의 정신적 부담에 대한 응답결과 선원 집단은 부담이 된다는 응답이 다소 우세하였고, 육상의 ISM 책임자 집단은 부담이 된다는 응답이 훨씬 우세하였다. ② ISM활동의 시간적 부담에 대한 응답 결과 선원 집단은 부담이 된다는 응답이 우세하였고, 육상의 ISM 책임자 집단은 부담이 된다는 응답이 훨씬 우세하였다. ③ STCW 협약 휴식기준을 충족하는데 있어 문제점 정도에 대한 응답 결과 선원 집단과 육상의 ISM 책임자 집단 모두 문제가 된다는 응답이 훨씬 많아 STCW 협약 상휴식시간 규정을 준수하기 어려운 여건임을 알 수 있었다. ④ ISM 전후 업무부담 증감 정도에 대한 응답 결과 선원 집단과 육상의 ISM 책임자 집단 모두 업무량이 증가하였다는 응답이 절대 다수를 차지하였다.<BR>  셋째, ISM 활동이 휴식시간 기준을 충족하기 어렵게 하는 문제시 되는 선종은 케미컬탱커, 컨테이너선, 유조선, 자동차운반선이 주로 지목되었다.<BR>  본 연구결과 국제해사협약의 도입으로 인하여 선원에게 부과되는 강행규정의 이행 유효성의 확보를 위한 대책의 마련이 절실히 요청된다는 결론을 얻을 수 있었다. 그 대책 방안으로서는 각종 강행협약의 제?개정에 의한 업무부담의 증가분을 분석하고 이를 선내 휴식시간과 승무기준에 반영하게 하는 어떤 제도를 고안할 필요가 있다.   This paper intends to examine the burden on seafarers as the final subject of implementing the mandatory international maritime conventions and to seek a reform measure through analyzing whether or not they are able to discharge efficiently the responsibilities imposed on them aboard ships. The methodology of this study includes identifying the seafarers" commitment related to the implementation of mandatory conventions, analysing the relevant documents submitted to the STW sub-committee 38 of the International Maritime Organization and conducting questionnaire survey and analyses to find the perception of both seafarers and company staff in charge of the ISM Code matters concerning the additional burden of shipboard duty due to the implementation of the compulsory laws and regulations introduced recently.<BR>  The result of the questionnaire survey and analyses are as follows: Firstly, the understanding on the ISM Code has been widely spreaded in relation to the degree of understanding on the contents of ISM Code and the safety management system and a great majority of seafarers and company staff responded that the level of conducting the safety management manual was average or higher which indicates that the level of ISM activities has been greatly enhanced since the introduction of the Code.<BR>  Secondly, ① with respect to the mental burden of the ISM activities the seafarers who answered burdensome was slightly superior in number and the company staff who answered burdensome was much superior in number. ② With respect to the burden of hours of work of the ISM activities the seafarers group who answered burdensome was superior in number and the company staff who answered burdensome was much superior in number. ③ In respect of the possibility of incompliance with the requirement of hours of rest set out in the 1978 STCW Convention as amended, most of both seafarers and company staff responded average or higher so that it could be noted that the provisions of hours of rest under the Convention was difficult to comply with in many cases. ④ Concerning increase of workload before and after ISM Code a great majority of both seafarers and company staff responded that the workload was increased.<BR>  Thirdly, as to the types of ships in which the ISM activities would pose difficulties in complying with the hours of rest requirements, it was pointed out that chemical tankers, container ships, oil tankers and car carriers were the most problematic type of ships.<BR>  As the result of this study it can be said that there is a great need to establish urgent countermeasures for ensuring the effectiveness of implementation of compulsory provisions imposed on the part of seafarers resulting from the introduction of various international maritime conventions. As a good countermeasure a system need to be designed whereby the increase of workload due to adoption or amendment of the various mandatory conventions is analysed and the increase of workload must be reflected in the hours of rest and manning scale.

나노급 정밀 구동을 위한 스핀들 모터-척 시스템 설계

김경호(Kim, Kyung-Ho),김하용(Kim, Ha-Yong),신부현(Shin, Bu-Hyun) 한국소음진동공학회 2009 한국소음진동공학회 논문집 Vol.19 No.6

The STW(servo track writing) system which is the process of writing servo signals on disks before assembling in drives uses the spindle motor-chuck mechanism to realize low cost because the spindle motor-chuck mechanism has merit which can simultaneously write multi-disk by piling up disks in hub. Therefore, when the spindle motor-chuck mechanism of horizontal type operates in high rotation speed it is necessary to reduce the effect of RRO(repeatable run-out) and NRRO(non-repeatable run-out) to achieve the high precision accuracy of nano-meter level during the STW process. In this paper, we analyzed that the slip in assembly surfaces can be caused by the mechanical tolerance and clamping force in hub-chuck mechanism and can affect NRRO performance. We designed springs for centering and clamping considering centrifugal force by the rotation speed and assembly condition. The experimental result showed NRRO performance improves about 30 % than case of weak clamping force. The result shows that the optimal design of the spindle motor-chuck mechanism can effectively reduce the effect of NRRO and RRO in STW process.

초고밀도 디스크 드라이브를 위한 반 진공 작동 환경에서 서보 트랙 기록 방법에 의한 RRO 저감에 대한 연구

한윤식,강심우 한국소음진동공학회 2004 한국소음진동공학회 논문집 Vol.14 No.11

In high-capacity disk drives with ever-growing track density, the allowable level of position error signal(PES) is becoming smaller and smaller. In order to achieve the high TPI(track per inch) disk drive, it is necessary to improve the writing accuracy during the servo track writing(STW) Process through the reduction of track mis-registration sources. Among the main contributors of the non-repeatable runout(NRRO) PES, the disk vibration and the head-stack assembly vibration is considered to be one of the most significant factors. Also the most contributors of repeatable runout(RRO) come from the contributors of NRRO which is written-in at the time of STW process. In this paper, the effect of NRRO on servo written-in RRO is Investigated by experimentally, and the experimental result shows that the written-in RRO can be effectively reduced through a STW process under low dense medium condition such as semi-vacuum.

2010년 STCW 개정협약의 주요 내용과 교육계의 대응

윤명오,성유창,Youn, Myung-Ou,Seong, Yu-Chang 해양환경안전학회 2010 해양환경안전학회지 Vol.16 No.3

1978년 STCW 협약은 해기사의 직무능력에 대한 국제적 최저 기준으로 제정되었으며 인적요인에 의해 발생되는 해양사고를 감소시키는 데 기여해왔다. STCW 협약은 선박의 운항환경 변화에 따라 부분적으로 수정되어 왔으며 1995년에 대폭적인 협약의 개정이 이뤄졌다. 이러한 개정 이 후에도 선박은 지속적으로 대형화, 고속화되어 왔을 뿐만 아니라 많은 첨단 기술이 도입되어 과거의 선박에 비하여 선박의 운항환경에 많은 변화가 있었다. 이러한 변화에 따라 선박을 운항할 해기사의 교육훈련 과정과 면허에서 확인되어야 할 직무능력에 대한 기준도 변화시켜야 할 필요성이 제기되었고, 이에 따라 2006년부터 STW 소위원회는 협약의 개정에 대해 논의를 시작하였으며 그 결과 2010년 6월 필리핀의 마닐라에서 개최된 외교회의에서 협약의 개정이 이뤄졌다. 이번 개정에서는 선박의 보안, 전자해도, 리더십 등에 대한 교육 훈련이 추가되었으며 본 연구는 최근에 개정된 협약의 내용을 정리하고, 이에 대한 해기교육 기관의 대응방안을 살펴보았다. The international convention on standards of training, certification and watch-keeping for seafarers, 1978(1978 STCW convention) has been established as a minimum standard and competence of seafarers, and contributed to reduce marine accidents caused by human errors. The convention has been partly amended several times according to environmental change of ship's operation and there were comprehensive revisions in so called 1995 amended STCW convention. In these years, ships are in tendency of increasing size and speed, and also adopted high technologies. These kinds of changes brought STW sub-committee up for discussions to modify the convention to cope with new environments from the year of 2006. As the result, major amendaments to STCW convention have been adopted at a diplomatic conference in Manila, Philippine in June 2010, thereby new global standards will be in force to train and certify seafarers to operate technologically advanced ships before long. This paper is to introduce major amendaments such as ship's security, ECDIS and leadership etc. in this Manila amendments and to clarify some articles to be adopted in programs for education and training of seafarers in Korea.

Robust Adaptive Gain for Suppression of Chattering in Sliding Mode Controller

Ali Amer ALRawi,Saadi Alobaidi,Stevica Graovac 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

This paper proposing a new design to improve sliding mode controller by employing an Adaptive Exponential Gain (AEG) for reducing the unwanted chattering phenomenon. The chattering reduction is achieved by using a new gain function of states feedback system combined with Conventional Sliding Mode Controller (CSMC). The value of the gain is calculated based on the value of the system states; so that a new value of sliding mode controller (SMC) gain always depending on the system stats as the corrective control term instead of discontinuous sign function. In SMC the amplitude of chattering is proportional to the magnitude of discontinuous control, this worrying issue can be handled if the magnitude of the control signal is reduced to a minimal value defined by exist of the conditions for the SMC. The application of this methodology AEG enables for reducing the control signal magnitude to the minimum possible value maintenance the property of SMC. The AEG algorithm shows an efficient reduction in system chattering as comparison between it and existing methods Super Twisting Algorithm (STW), used to treatment of chattering phenomenon. Moreover, the new algorithm is more robust, accurate and high responses to external noise and any change in system parameters.

Servo Track Writer의 Settling Control을 위한 Feedforward 제어 입력의 최적 설계

윤재상 ( Jae Sang Yun ),이충우 ( Choong Woo Lee ),강현재 ( Hyun Jae Kang ),정정주 ( Chung Choo Chung ),서상민 ( Sang Min Suh ),오동호 ( Dong Ho Oh ),이호성 ( Ho Sung Lee ) 정보저장시스템학회 2007 정보저장시스템학회논문집 Vol.3 No.1