• Title/Summary/Keyword: force improvement effectiveness

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Reduction of Booming Noise Using Damper Clutch Disk on the Drive Shaft of Commercial Small Truck (상업용 소형 트럭의 구동축에서 댐퍼 클러치 디스크를 이용한 부밍 소음 저감)

  • Kim, Yong Dae;Choi, Byungjae
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.25 no.6
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    • pp.377-383
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    • 2015
  • Torsion mode or bending mode of drive-line for rear-wheel drive vehicle exists in low frequency band. If resonance exists there between natural mode of driveline and powertrain excitation force, drive-line will manifest excessive vibration response. Also, the vibration response can be transmitted to vehicle body and can induce booming noise. A vehicle in this study exhibits a booming noise problem under specific transmission gear condition. To draw performance improvement plan, finite element analysis technique was used. Modification was evaluated qualitatively and priorities were derived. Finally, effectiveness of best modification was verified through test and full vehicle FE analysis.

Improvement of Dynamic Characteristic of LDM by Using I-PD Algorithm (외란에 강인한 I-PD 제어에 의한 LDM의 동특성 개선)

  • Kim, S.W.;Baek, S.H.;Yoon, S.Y.;Myung, N.Y.;Chang, H.S.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.754-756
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    • 2000
  • In this paper, the I-PD control algorithm using the coefficient diagram method(CDM) controller design of the Linear DC Motor(LDM) is presented. Recently LDM has been used to obtain the fine results of the dynamic characteristic for straightly moving condition. The I-PD control algorithm has a robust response to force disturbance. The effectiveness of I-PD is shown by simulations and comparison with PID.

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A Reinforcement Effect of Pile Foundation by Compaction Grouting System in Railroad Station Building (Compaction Grouting System에 의한 철도역사건물 파일기초보강효과)

  • Chun, Byung-Sik;Choi, Seung-Kwon;Do, Jong-Nam;Sung, Hwa-Don
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1364-1368
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    • 2006
  • By the countermeasure which is caused by with railroad station ground settlement it applied a CGS in each independent foundation. The effectiveness of the ground improvement and the bearing capacity of the compaction pile has been verified by the Cone Penetration Test(CPT) and Load Test. Test result show that penetration resistance and the cone friction force increased a lot and settlement 13.475mm as the standard settlement 40.0mm appeared at below. Also uniaxial compression test result $278kg/cm^2$ as the standard $150kg/cm^2$ appeared far a lot.

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Optimal Design of Hybrid Control System through Inter-Building Connection (빌딩간 연결을 통한 복합제어시스템의 최적설계)

  • Park, Kwan-Soon;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.32 no.6
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    • pp.81-88
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    • 2017
  • This study deals with the optimal design of a hybrid control system composed of a combination of active control system and passive control system for effective seismic performance improvement of two adjacent structures. The proposed hybrid control system adopts a configuration of installing an active control device in one building and connecting two adjacent structures with a passive control device so that the one-side active control force can be bi-directionally applied to both buildings through the passive connecting devices. In order to derive the optimal performance of the proposed system, the design parameters of the passive and active control systems were searched using the genetic algorithm. Numerical simulations of 10-story and 8-story buildings have been performed to verify the effectiveness of the proposed technique. For the purpose of comparison, the conventional independent control system with two identical active control systems being installed separately for each structure was also optimally designed and its seismic response has been evaluated as well. From the comparative results of the two control systems, it is demonstrated that the proposed hybrid control system requires larger control force for its one-side active control device than the conventional independent control system does for each of both-side active devices, but quite less than the total control force required for both-side devices of the independent control system, while maintaining similar seismic performance. Therefore, the proposed system is more economical and reliable than the conventional independent control system with two identical active devices.

Assessment of the Effectiveness of Unfair Trading Prevention Acts in Construction Industry (건설공사 불공정거래 방지제도 실효성 평가 및 개선방안)

  • Kim, Sung-Il;Cho, Jung-Hee;Chang, Chul-Ki
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.1
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    • pp.65-73
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    • 2018
  • Since unfair trading practices between participants in construction project are common, the government has enforced several policies and systems to prevent or minimize the unfair trading practices in construction industry. However, not much attention has been paid to figure out which policies or acts are working or not. This paper analyzed the effectiveness of the policies and acts which are being implemented to prevent unfair trading practices and provided several suggestions to improve the performance of those acts. Survey was conducted to industry experts to collect data regarding their perceptions on those policies and acts. Then the effectiveness of the policies and acts were analyzed in terms of their importance and performance through IPA (Importance-Performance Analysis) based on the survey result. It was found through IPA that execution related acts such as investigation, exposure, and punishment for unfair trading practice have shown low effectiveness in entire construction process and dispute arbitration and mediation related center operated by authority showed low performance too. To improve the effectiveness of those acts, dispute arbitration system improvement, investigation & reporting system consolidation and enhancement practical binding force of punishment and penalty were suggested. Most of all, rules and culture for fair trading should become more established in construction industry by preventing conflict among participants through active communication.

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

  • Kim, Min-Seok
    • Strategy21
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    • s.33
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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.

A Case Study on Smart Livestock with Improved Productivity after Information and Communications Technologies Introduction

  • Kim, Gok Mi
    • International Journal of Advanced Culture Technology
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    • v.9 no.1
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    • pp.177-182
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    • 2021
  • The fourth industrial revolution based on information and communication technology (ICT) becomes the center of society, and the overall industrial structure is also changing significantly. ICT refers to the hardware of information devices and the software technologies required for the operation and information management of these devices, and any means of collecting, producing, processing, preserving, communicating and utilizing them. ICT is integrated into industries and services or combined with new technologies in various fields such as robotics and nanotechnology to connect all products and services to the network. The development of ICT, which continuously creates new products and services, has spread to all sectors of the industry, affecting not only daily life but also the livestock sector recently. In agriculture, ICT technology can reduce production costs by efficiently managing labor and energy because it can improve quality and yield based on data on environmental and growth information such as temperature, humidity, light and soil. In particular, smart livestock is considered suitable for achieving livestock management goals because it can reduce labor force and improve productivity by remotely and automatically managing accurate information necessary for raising and breeding livestock with ICT devices. The purpose of this study is to propose the need for ICT technology by comparing farm productivity before and after ICT is introduced. The method of the study is to compare the productivity before and after the introduction of ICT in Korean beef farms, pig farms, and poultry farms. The effectiveness of the study proved the excellence of ICT technology through the production results before ICT introduction and the productivity improvement case of livestock farms that efficiently operated manpower management and reduced labor force after ICT introduction. The conclusion of this paper is to present the need for smart livestock through ICT adoption through case study results.

Multiple Pounding Tuned Mass Damper (MPTMD) control on benchmark tower subjected to earthquake excitations

  • Lin, Wei;Lin, Yinglu;Song, Gangbing;Li, Jun
    • Earthquakes and Structures
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    • v.11 no.6
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    • pp.1123-1141
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    • 2016
  • To explore the application of traditional tuned mass dampers (TMDs) to the earthquake induced vibration control problem, a pounding tuned mass damper (PTMD) is proposed by adding a viscoelastic limitation to the traditional TMD. In the proposed PTMD, the vibration energy can be further dissipated through the impact between the attached mass and the viscoelastic layer. More energy dissipation modes can guarantee better control effectiveness under a suite of excitations. To further reduce mass ratio and enhance the implementation of the PTMD control, multiple PTMDs (MPTMD) control is then presented. After the experimental validation of the proposed improved Hertz based pounding model, the basic equations of the MPTMD controlled system are obtained. Numerical simulation is conducted on the benchmark model of the Canton Tower. The control effectiveness of the PTMD and the MPTMD is analyzed and compared under different earthquake inputs. The sensitivity and the optimization of the design parameters are also investigated. It is demonstrated that PTMDs have better control efficiency over the traditional TMDs, especially under more severe excitation. The control performance can be further improved with MPTMD control. The robustness can be enhanced while the attached mass for each PTMD can be greatly reduced. It is also demonstrated through the simulation that a non-uniformly distributed MPTMD has better control performance than the uniformly distributed one. Parameter study is carried out for both the PTMD and the MPTMD systems. Finally, the optimization of the design parameters, including mass ratio, initial gap value, and number of PTMD in the MPTMD system, is performed for control improvement.

The Effectiveness of Information Protection and Improvement Plan Based on SMEs Consulting Case

  • Kim, Jae-Nam
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.11
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    • pp.201-208
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    • 2019
  • In the phono-sapiens era of the intelligence information society, most business activities are increasingly dependent on networks and information systems. SMEs, which occupy the majority of Korean companies, are increasingly possessing the value and technology of their information assets, and their ability to protect core technologies that are the driving force of corporate growth will be the most important competitiveness of enterprises. Accordingly, the Ministry of Science and ICT and the Korea Internet & Security Agency(KISA) provides a foundation for minimizing the damage from cyber threats such as hacking and information leakage by evaluating the current information protection level of SMEs and enhancing information protection capability by supporting a high level of customized information protection consulting. In this study, we analyze the effectiveness of information protection based on the results of KISA SMEs consulting. In addition, by identifying problems and limitations derived from SMEs information protection consulting results, SMEs should propose measures to improve information security of SMEs that can manage information protection management system more efficiently and effectively.

An Assessment of the Revitalization Policy of Traditional Market and Its Alternative: A Case Study of Gyeongbuk Province (재래시장 활성화 정책의 평가와 대안 모색: 경상북도를 사례로)

  • Lee, Jae-Ha
    • Journal of the Economic Geographical Society of Korea
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    • v.10 no.3
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    • pp.304-318
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    • 2007
  • This study aims to assess an effectiveness of the revitalization policy of traditional market which has been put in force since the late 1990's through a case study of Gyeongbuk province in Korea. According to a qualitative assessment of the improvement project of market facilities and the modernization project of marketing technique, each project has little effect. This seems to be caused by the existing revitalization policy without full considerations of reinforcing the spatial competitiveness of traditional markets. This study suggests an alternative of the revitalization policy of traditional markets concentrating on the spatial competitiveness of them.

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