• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.5
• /
• pp.1345-1359
• /
• 1996

This paper presents a floating point arithmetic unit (FPAU) for supescalar microprocessor that executes fifteen operations such as addition, subtraction, data format converting, and compare operation using two pipelined arithmetic paths and new rounding and normalization scheme. By using two pipelined arithmetic paths, each aritchmetic operation can be assigned into appropriate arithmetic path which high speed operation is possible. The proposed normalization an rouding scheme enables the FPAU to execute roundig operation in parallel with normalization and to reduce timing delay of post-normalization. And by predicting leading one position of results using input operands, leading one detection(LOD) operation to normalize results in the conventional arithmetic unit can be eliminated. Because the FPAU can execuate fifteen single-precision or double-precision floating-point arithmetic operations through three-stage pipelined datapath and support IEEE standard 754, it has appropriate structure which can be ingegrated into superscalar microprocessor.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.377-385
• /
• 2007

The importance of maintenance of rail surface defects is increasing more according to the KTX operation. That is because during high speed operation of rolling stock, rail surface defects may cause shortened fatigue life of rail, acceleration of track degradation and reduced ride comfort. The paper was intended to study the establishment of rail grinding criteria of high-speed railway lines considering the KTX operation circumstances. For this, the specimens of UIC 60 rail on Kyeong-Bu high-speed operation lines were collected and they were analyzed for metallographic structure and tested for the hardness. By analyzing the test results to the factors affecting the RCF causing the defects of rail surface, the study suggested the rail grinding criteria of the domestic high speed railway lines. As the factors affecting RCF, passing tonnage, running speed and track condition are considered.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.23 no.58
• /
• pp.17-27
• /
• 2000

In FMS where tool movement policy is adopted, a mathematical model has been developed which determines the selection of a tool type for each operation and tool loading-part assignment simultaneouly. The objective is to minimize the total cost of operation including machining time cost, tool cost, tool replacement and loading time cost, and tool change time cost. Due to the complexity of the problem, an approximate solution procedure has been developed utilizing the special structure of the model. Tool selection was determined first to allocate one tool type to each operation considering more than one tool type alternatives for each operation. Tool loading-part assignment was determined to minimize tile total number of tool changes due to part mix based on the tool selection.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.3 no.4
• /
• pp.426-436
• /
• 1998

Identification of fault current during the operation of a power semiconductor switch and activation of suitable remedial actions are important for reliable operation of power converters. A short circuit is a basic and severe fault situation in a circuit structure such as voltage source converters. This paper presents a new active protection circuit for fast and precise clamping and safe shutdown of fault currents of the IGBTs. This circuit allows operation of the IGBTs with a higher on-state gate voltage, which can thereby reduce the conduction loss in the device without compromising the short circuit protection characteristics. The operation of the circuit is studied under various conditions, considering variation of temperature, rising rate of fault current, gate voltage value, and protection circuit parameters. An evaluation of the operation of the circuit is made using IGBTs from different to confirm the effectiveness of the protection circuit.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.1 no.3
• /
• pp.312-319
• /
• 2012

The operation principle of an axial flux-switching hybrid excitation synchronous machine (AFHESM) is analyzed and its topology structures are proposed in this paper. After some comprehensive analysis of the operation principle to axial flux electrical machine, flux-switching electrical machine and hybrid excitation electrical machine, the operation principle of AFHESM is given. Combined with some typical topological structures of hybrid excitation electrical machine, some possible topological structures are proposed and some comprehensive comparisons are carried out. The analysis results show that the stator-separated AFHESM has some advantages such as less AM turns, less impact on the demagnetization of PM, less magnetic flux-leakage and higher efficiency compared to other topologies.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.2
• /
• pp.311-317
• /
• 2010

This paper deals with operation characteristics of a written-pole motor (WPM), having that of a permanent magnet (PM) synchronous motor and induction motor at once. The WPM also has a magnet layer on the surface of the rotor and the exciter pole that is a device to make the magnet layer magnetized during the operation. This study, introducing a fundamental structure and operation characteristics of a single-phase WPM, proposes a initial design method. With those ground, a 130W, single-phase WPM that is designed for a home appliance is presented and verified with a performance through the experiment.

• Korean small business review
• /
• v.43 no.4
• /
• pp.155-172
• /
• 2021

This research means that it analyzed the conflict structure of key stakeholders in the operation and management of the Regulation Free Zone. The analysis results are as follows. First, for the safety review related to the amendment of the law, the process of presenting a preliminary review opinion is additionally required. Second, institutional improvement is needed for the complicated preliminary preparation stage in the management system issue. Third, there is the issue of whether to provide an incentive structure to the local innovation ecosystem or to leave it to the autonomy of the participating companies and guarantee the choice in the post-management issue. In the future, this research suggests a method to systematically prepare a micro-policy demand identification process through continuous monitoring using the Q method.

• Journal of the Microelectronics and Packaging Society
• /
• v.30 no.3
• /
• pp.73-77
• /
• 2023

In this study, we developed a Multi-level FeRAM (Ferroelectrics random access memory) device utilizing different ferroelectric materials and analyzed its operation through C-V analysis using simulations. To achieve Multi-level operation, we proposed an MFM (Multi-Ferroelectric Material) structure by depositing two different ferroelectric materials with distinct properties horizontally on the same bottom electrode and subsequently adding a gate electrode on top. By analyzing C-V peaks based on the polarization phenomenon occurring under different voltage conditions for the two materials, we confirmed the feasibility of achieving Multi-level operation, where either one or both of the materials can be polarized. Furthermore, we validated the process for implementing the proposed structure using semiconductor fabrication through process simulations. These results signify the significance of the new structure as it allows storing multiple states in a single memory cell, thereby greatly enhancing memory integration.

• Korean System Dynamics Review
• /
• v.17 no.2
• /
• pp.81-99
• /
• 2016

The service for waterworks is important infrastructure structuring the cities and the public properties affecting the health and the abundant lives of the residents at the same time. However, the waterworks project still has many problems in reality in spite of the continuous efforts from the nation, local governments and many related people in waterworks projects. From the aspect of the situation, this purpose of this study is to review the actual operation state and the operation principle on the basis of the accidents in the system and to suggest the policy leverages for accurate diagnosis of the waterworks project and for the efficient operation. The operation structure of the service for waterworks is the complicated system showing the overlapped forms of the relation with other various factors. Moreover, as this has been influenced by other external environments, it has flexible features that can be changed by unexpected factors even if the internally close causality has been established The domestic local operation of waterworks have been divided by an administrative district and it causes inefficiency in the aspect of the country and the local government with small sized of budget faces the insufficient investments. These phenomena have been shown in some small sized areas located in Chungcheongbuk-do and, making a realistic suggestion by the related local government to improve the waterworks operation project is urgent. For this reason, this study is to lead the policy leverages to increase the efficiency of the service for waterworks and to stabilize the structure of virtuous circle in the system. At first, the reformation of the waterworks structure should be performed after the various supports and system maintenance. At second, the service quality should be improved through the creativity in management and the consideration of the efficiency by the participation of private enterprises for waterworks service. At third, through the specialized waterworks operation, the quality improvement of the waterworks and satisfying the standard of natural environment should be related. In this context, the fundamental solutions for the problems of domestic waterworks service and finding realistic alternatives are considered to be the priority for the waterworks project to be operated efficiently.

• Language and Information
• /
• v.18 no.2
• /
• pp.1-29
• /
• 2014

Relativization is one of the common syntactic operations to merge two different clauses into a single information unit. This operation plays a pivotal role to structuralize multiple clauses cohesively as well as serves to specify the property an individual has within the context. That implies that relativization contributes to information structure of multiclausal sentences. In this context, this paper delves into information structure of relative clauses in English with an eye toward creation of a computational model from a standpoint of machine translation. The current work employs Head-driven Phrase Structure Grammar (HPSG, Pollard and Sag (1994)) as a theory of grammar and Minimal Recursion Semantics (MRS, Copestake et al. (2005) as a meaning representation system. Building upon these formalisms, this paper addresses how information structure of relative clauses can be represented and constrained. The current work makes use of Individual CONStraints (ICONS) for modeling relative clauses with respect to information structure. The current work also investigates which relative clause involves which information structure constraint. The present study argues that non-restrictive relative clauses impose a more specific constraint on information structure than restrictive relative clauses.