• 제목/요약/키워드: force capability

검색결과 460건 처리시간 0.027초

유한요소법을 이용한 보강롤 구동 4단 냉간압연기에서의 압연하중 및 스트립 두께 예측 (FEM Based Approach to Predict Rolling Force and Strip Thickness in 4-High Cold Rolling Mill Driven by Backup-Roll)

  • 이재현;변상민;박흥식
    • 한국기계가공학회지
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    • 제8권4호
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    • pp.129-135
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    • 2009
  • In this paper, a finite element model is presented for the prediction of roll force and strip thickness in a backup-roll-drive mill. The proposed FE model is focused mainly on analyzing the elastic/plastic behavior between a work roll and a strip as well as the rigid/plastic behavior between a backup roll and a work roll. The capability of the proposed model is demonstrated through application to 4-high silicon steel rolling mill at POSCO. Results show that the predicted roll force and strip thickness rolled accurately agree with the measured them. It is also illustrated that the proper position of work roll displaced to one side from the vertical centerline of the backup-roll may be determined by minimizing the horizontal force of work roll.

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퍼지이론을 이용한 선삭의 절삭력제어 (Cutting Force Control of Turning Process Using Fuzzy Theory)

  • 노상현;정선환;김교형
    • 대한기계학회논문집
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    • 제18권1호
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    • pp.113-120
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    • 1994
  • The dynamic characteristics of turning processes are complex, non-linear and time-varying. Consequently, the conventional techniques based on crisp mathematical model may not guarantee cutting force regulation. This paper presents a fuzzy controller which can regulate cutting force in turning process under varying cutting conditions. The fuzzy control rules are extablished from operator experience and expert knowledge about the process dynamics. Regulation which increases productivity and tool life is achieved by adjusting feedrate according to the variation of cutting conditions. The performance of the proposed controller is evaluated by cutting experiments in the converted conventional lathe. The results of experiments show that the proposed fuzzy controller has a good cutting force regulation capability in spite of the variation of cutting conditions.

냉간 압연에서 압하력 분포 예측 - Part I : 수식 모델 개발 (Prediction of Roll Force Profile in Cold Rolling - Part I : Development of a Mathematical Model)

  • 남승연;황상무
    • 소성∙가공
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    • 제28권4호
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    • pp.190-196
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    • 2019
  • The capability of accurately predicting the roll force profile across a strip in the bite zone in cold rolling process is vital for the calculation of strip profile. This paper presents a derivation of a precision mathematical model for predicting variations in the roll force across a strip in cold rolling. While the derivation is based on an approximate 3-D theory of rolling, this mathematical model also considers plastic deformation in the pre-deformation region which is located close to the roll entrance before the strip enters the bite zone. Finally, the mathematical model is expressed as a boundary value problem, and it predicts the roll force profile and tension profile in addition to lateral plastic strain profile.

미국방성의 전력개발 프로세스를 활용한 스마트 시티 개념설계 방안 (Concept Design Method of Smart City using Defense System Development Process of DoD)

  • 이중윤
    • 시스템엔지니어링학술지
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    • 제15권2호
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    • pp.98-107
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    • 2019
  • The defense system development process is a process of developing various systems that perform functions in various functional areas such as battlefield awareness, command control, force application, and logistical support. In other words, the defense system development process is a process of developing many systems simultaneously in various functional areas. Various systems developed through this process should be interoperable so that they can be integrated and operated in a joint warfighting environment. To successfully implement this, the US Department of Defense uses the Joint Capability Integrated Development System(JCIDS) for the defense system development, and within this JCIDS processes the Capability Based Assessment(CBA) methodology as its core technology. This CBA methodology transforms the mission activity requirements to functional capability requirements logically and transforms the functional capability requirements to system requirements logically also. Smart City is a city that improves the convenience and quality of life of the citizen by integrates various systems that perform various functions of the city and smarties various functional systems with smart services by using IT technology. In other words, defense system development and smart city development have a common feature of the process of developing many systems simultaneously in various functional areas. In order to address the problem of having to develop many systems simultaneously in each functional area, it is important to logically transform the various mission scenarios into functions and logically transform the functions into systems. Therefore, a joint capability integrated development system and its core methodology, Capability Based Assessment(CBA), can be applied to smart city development. This paper proposes a method for performing a smart city concept design method using the capability based evaluation (CBA) method.

기능성과 보온성 향상을 위한 공군 정비파카 개발 및 평가 (Development and Evaluation of Air Force Mechanic Parka to Enhance the Functions and Insulation)

  • 이성지;최영림;남윤자
    • 한국의류산업학회지
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    • 제14권2호
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    • pp.294-303
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    • 2012
  • This study was designed to develop air force mechanic parka, evaluate it, and ultimately provide functionally superior parka to the air force. The development process was 1) conducting a survey, 2) identifying problems and shortcomings of currently-supplied parkas, and 3) improving the design, pattern and materials. The newly-developed parkas were evaluated in terms of their ease of fit, clothing mobility, and insulation. Ease of fit was evaluated by subjects' sensory tests, and clothing mobility was by fitness-for-motion tests and range-of-motion tests using a Goniometer. Evaluation on insulation was conducted by thermal manikins. Findings of this study were as follows: 1. In the subjective evaluation on clothing mobility, new parkas were considered to have sufficient ease of fit while previous ones scored much lower, confirming the improvement of the new version. 2. Both subjective tests and ROM measurements on fitness for motion verified the superiority of the new parkas. 3. Insulation tests found that although insulation capability of newly-developed parkas was at a similar level to those of the previous ones, their insulation capability per unit weight was superior, demonstrating that new parkas were better at blocking heat conduction. When making changes in parka patterns and designs to enhance the mobility, it was necessary to maintain the insulation function. The new parkas developed by this study was verified to be superior to the previous ones in their insulation and clothing mobility.

핵위협하 국지도발 대비 대응전략 발전방향 (South Korea's strategy to cope with local provocations by nuclear armed North Korea)

  • 김태우
    • Strategy21
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    • 통권31호
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    • pp.57-84
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    • 2013
  • North Korea's continuous threats and provocative behaviors have aggravated tension on the Korean peninsula particularly with the recent nuclear weapons test. South Korea's best way to cope with this situation is to maintain the balance among three policy directions: dialogue, sanctions, and deterrence. Among the three, I argue that deterrence should be prioritized. There are different sources of deterrence such as military power, economic power, and diplomatic clouts. States can build deterrence capability independently. Alternatively, they may do so through relations with other states including alliances, bilateral relations, or multilateral relations in the international community. What South Korea needs most urgently is to maintain deterrence against North Korea's local provocations through the enhancement of independent military capability particularly by addressing the asymmetric vulnerability between militaries of the South and the North. Most of all, the South Korean government should recognize the seriousness of the negative consequences that North Korea's 'Nuclear shadow strategy' would bring about for the inter-Korea relations and security situations in Northeast Asia. Based on this understanding, it should develop an 'assertive deterrence strategy' that emphasizes 'multi-purpose, multi-stage, and tailored deterrence whose main idea lies in punitive retaliation.' This deterrence strategy requires a flexible targeting policy and a variety of retaliatory measures capable of taking out all targets in North Korea. At the same time, the force structures of the army, the air force, and the navy should be improved in a way that maximizes their deterrence capability. For example, the army should work on expanding the guided missile command and the special forces command and reforming the reserve forces. The navy and the air force should increase striking capabilities including air-to-ground, ship-to-ground, and submarine-to-ground strikes to a great extent. The marine corps can enhance its deterrence capability by changing the force structure from the stationary defense-oriented one that would have to suffer some degree of troop attrition at the early stage of hostilities to the one that focuses on 'counteroffensive landing operations.' The government should continue efforts for defense reform in order to obtain these capabilities while building the 'Korean-style triad system' that consists of advanced air, ground, and surface/ subsurface weapon systems. Besides these measures, South Korea should start to acquire a minimum level of nuclear potential within the legal boundary that the international law defines. For this, South Korea should withdraw from the Nuclear Non-proliferation Treaty. Moreover, it should obtain the right to process and enrich uranium through changing the U.S.-South Korea nuclear cooperation treaty. Whether or not we should be armed with nuclear weapons should not be understood in terms of "all or nothing." We should consider an 'in-between' option as the Japanese case proves. With regard to the wartime OPCON transition, we need to re-consider the timing of the transition as an effort to demonstrate the costliness of North Korea's provocative behaviors. If impossible, South Korea should take measures to make the Strategic Alliance 2015 serve as a persisting deterrence system against North Korea. As the last point, all the following governments of South Korea should keep in mind that continuing reconciliatory efforts should always be pursued along with other security policies toward North Korea.

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방위력개선사업비 편성.확보의 합리성과 안정성 제고방안 -국방중기계획 연부액의 편성 및 확보방안을 중심으로- (A Study on Improvement of Rationality and Stability of Allocation and Procurement of Defense Capability Improvement Cost -Focused on the Yearly Allocation and Procurement of Mid-Term Defense Plan-)

  • 최준혁;이필중
    • 한국국방경영분석학회지
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    • 제34권1호
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    • pp.117-135
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    • 2008
  • 현재 세계 각국은 탈냉전 이후 격변하는 안보환경 속에서 생존을 위한 다양한 도전에 직면해 있다. 이에 한국군도 '국방개혁 2020'을 통한 첨단 정보과학군으로의 변모를 죄하고 있으며, 이는 필연적으로 새로운 군사력 소요를 창출하게 되었다. 그리고 이와 같은 군사력 건설의 성공적인 추진을 위해 방위산업 및 국방예산의 중요성은 더욱 증대되었다. 하지만 현재 한국의 방위산업은 심각한 어려움을 겪고 있으며, 더욱이 방위력개선사업비의 낮은 합리성 안정성은 이러한 실태를 더욱 악화시켜 왔다. 이와 같은 상황에서 한국 방위산업의 발전과 한국군 군사력 소요의 적기 충족을 위해서는 방위력개선사업비의 합리성 안정성 제고방안 강구가 시급하다. 따라서 본 연구의 목적은 한국 방위력개선사업 비의 합리성 안정성 제고를 위한, 방위력개선사업분야 국방중기계획의 연부액 편성체계 개선 및 국가재정운용계획과 국방중기계획의 연계 강화방안을 제시하는 데 있다. 한국 국방목표의 성공적 달성을 위해 국방중기계획의 연부액 편성체계 개선을 통해 방위력개선사업비의 합리성을 제고하고 안정성 제고를 위해 이를 국가재정운용계획과 연계시켜 최근 국가재정법 발효 등으로 변화가 불가피한 한국의 국방예산 편성체계에서 방위력개선사업비의 시기적절한 변화를 도모하고자 한다.

신호전송 시간지연을 갖는 원격조작시스템의 힘반영 위치제어 (A Force Reflecting Position Control for Teleoperation Systems with Signal Transmission Time Delay)

  • 안성호;진재현;박병석;윤지섭
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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    • pp.157-160
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    • 2002
  • When the teleoperation system has a signal transmission time delay between slave system and control system, the position tracking performance of the slave system and system stability are likely to be deteriorated. This paper proposes a force reflecting position control scheme for teleoperation system with signal transmission time delay. The proposed scheme not only satisfy the system internal stability but also improves the position tracking performance with disturbance rejection capability. The simulation results show that the proposed control method provides excellent performances.

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중국군의 해양작전능력과 한국군의 과제 (PRC Maritime Operational Capability and the Task for the ROK Military)

  • 김민석
    • Strategy21
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    • 통권33호
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    • pp.65-112
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    • 2014
  • Recent trends show that the PRC has stepped aside its "army-centered approach" and placed greater emphasis on its Navy and Air Force for a wider range of operations, thereby reducing its ground force and harnessing its economic power and military technology into naval development. A quantitative growth of the PLA Navy itself is no surprise as this is not a recent phenomenon. Now is the time to pay closer attention to the level of PRC naval force's performance and the extent of its warfighting capacity in the maritime domain. It is also worth asking what China can do with its widening naval power foundation. In short, it is time to delve into several possible scenarios I which the PRC poses a real threat. With this in mind, in Section Two the paper seeks to observe the construction progress of PRC's naval power and its future prospects up to the year 2020, and categorize time frame according to its major force improvement trends. By analyzing qualitative improvements made over time, such as the scale of investment and the number of ships compared to increase in displacement (tonnage), this paper attempts to identify salient features in the construction of naval power. Chapter Three sets out performance evaluation on each type of PRC naval ships as well as capabilities of the Navy, Air Force, the Second Artillery (i.e., strategic missile forces) and satellites that could support maritime warfare. Finall, the concluding chapter estimates the PRC's maritime warfighting capability as anticipated in respective conflict scenarios, and considers its impact on the Korean Peninsula and proposes the directions ROK should steer in response. First of all, since the 1980s the PRC navy has undergone transitions as the focus of its military strategic outlook shifted from ground warfare to maritime warfare, and within 30 years of its effort to construct naval power while greatly reducing the size of its ground forces, the PRC has succeeded in building its naval power next to the U.S.'s in the world in terms of number, with acquisition of an aircraft carrier, Chinese-version of the Aegis, submarines and so on. The PRC also enjoys great potentials to qualitatively develop its forces such as indigenous aircraft carriers, next-generation strategic submarines, next-generation destroyers and so forth, which is possible because the PRC has accumulated its independent production capabilities in the process of its 30-year-long efforts. Secondly, one could argue that ROK still has its chances of coping with the PRC in naval power since, despite its continuous efforts, many estimate that the PRC naval force is roughly ten or more years behind that of superpowers such as the U.S., on areas including radar detection capability, EW capability, C4I and data-link systems, doctrines on force employment as well as tactics, and such gap cannot be easily overcome. The most probable scenarios involving the PRC in sea areas surrounding the Korean Peninsula are: first, upon the outbreak of war in the peninsula, the PRC may pursue military intervention through sea, thereby undermining efforts of the ROK-U.S. combined operations; second, ROK-PRC or PRC-Japan conflicts over maritime jurisdiction or ownership over the Senkaku/Diaoyu islands could inflict damage to ROK territorial sovereignty or economic gains. The PRC would likely attempt to resolve the conflict employing blitzkrieg tactics before U.S. forces arrive on the scene, while at the same time delaying and denying access of the incoming U.S. forces. If this proves unattainable, the PRC could take a course of action adopting "long-term attrition warfare," thus weakening its enemy's sustainability. All in all, thiss paper makes three proposals on how the ROK should respond. First, modern warfare as well as the emergent future warfare demonstrates that the center stage of battle is no longer the domestic territory, but rather further away into the sea and space. In this respect, the ROKN should take advantage of the distinct feature of battle space on the peninsula, which is surrounded by the seas, and obtain capabilities to intercept more than 50 percent of the enemy's ballistic missiles, including those of North Korea. In tandem with this capacity, employment of a large scale of UAV/F Carrier for Kill Chain operations should enhance effectiveness. This is because conditions are more favorable to defend from sea, on matters concerning accuracy rates against enemy targets, minimized threat of friendly damage, and cost effectiveness. Second, to maintain readiness for a North Korean crisis where timely deployment of US forces is not possible, the ROKN ought to obtain capabilities to hold the enemy attack at bay while deterring PRC naval intervention. It is also argued that ROKN should strengthen its power so as to protect national interests in the seas surrounding the peninsula without support from the USN, should ROK-PRC or ROK-Japan conflict arise concerning maritime jurisprudence. Third, the ROK should fortify infrastructures for independent construction of naval power and expand its R&D efforts, and for this purpose, the ROK should make the most of the advantages stemming from the ROK-U.S. alliance inducing active support from the United States. The rationale behind this argument is that while it is strategically effective to rely on alliance or jump on the bandwagon, the ultimate goal is always to acquire an independent response capability as much as possible.

국방 전력지원체계 기술수준조사에 대한 연구 (A Study on Defense Technology Level Evaluation of Force Support Systems)

  • 이동헌;홍성돈;김영건
    • 제어로봇시스템학회논문지
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    • 제20권2호
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    • pp.112-119
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    • 2014
  • A force support system is composed of capital components such as combat equipments, supplies and so on to enable constant fighting power capability. Private technology level evaluation is on the rise as an important spin-on method in force support systems, which requires 92% of total munitions requirements, to obtain superior private technology. The evaluation of the private sector technology level on Korean force support systems has been conducted for the first time as follows: this research chose 38 items to be acquired within 2-3 years and grouped either identical or similar technology among those 38 items. A technology evaluating method was established based on the analysis of domestic and foreign technology level evaluations. Evaluation was performed by a Delphi survey from 180 private and military experts. To obtain an objective index and raise political availability, a technology system map and standard document were developed and applied to all 38 items.