• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.11a
• /
• pp.184-185
• /
• 2008

Modal analysis is an important and essential process in design of a high speed machining center. Generally, modal analysis of a built-in spindle system has not taken the work piece's shape and dimension into consideration. Since small and long work pieces influence greatly the natural frequency of the entire system, the high speed spindle system which continuously makes small machine parts by long work pieces for improvement of machining time has to consider the machining work pieces. Therefore frequency characteristics of the spindle system with long work pieces are studied in this paper.

• IE interfaces
• /
• v.23 no.2
• /
• pp.126-138
• /
• 2010

Marine equipment makers today face a multitude of challenges including the needs of an internal system for easy management of their business processes and a collaboration system to streamline communications with the parent company, increasing product complexity and heightened requirements for information technology. In this research, a BPM-ERP system called Biz $Tower^{(R)}$ was implemented based on cloud computing for especially, small and medium marine equipment makers to standardize and visualize the entire business process from order placement to release. This system also provides their parent company with visibility into the status of orders and user can easily access the system on the web at a low price through cloud computing service. Thus far, this paper demonstrates the applicability of Biz $Tower^{(R)}$ to improve management visibility, process performance, and collaboration with the parent company for small and medium marine equipment makers.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.32 no.1
• /
• pp.147-156
• /
• 2009

The introduction and application of IT(Information Technology) to a company has become to be viewed as a key factor for the business competitiveness and improved productivity. This study presents an approach to evaluation of a company's informatization level, which is especially appropriate for small and medium enterprises. The proposed evaluation method, based on the traditional questionnaire approaches, considers the various characteristics of the company, e.g., types of business, characteristics of customers, and locations of supply chains etc. A web-based system was developed to enable users to obtain the evaluation results from the evaluation method. The system also provides a function to produce valuable strategies for informatization by utilizing the case base which will be cumulated by repetitive evaluation requests. Finally, a real case was analyzed in order to verify the practicality of the evaluation system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.12
• /
• pp.1688-1693
• /
• 2013

A small-scale wind power generation system with a switched-mode rectifier(SMR) is proposed. To simplify the converter circuit of the wind power generation system, the synchronous inductors of the permanent magnet synchronous generator(PMSG) replace the inductor for the boost converter. The sensorless maximum power point tracking(MPPT) control is carried out for the wind power generation system with the SMR. The proposed system is verified through the simulations and the experiments.

• Journal of Power System Engineering
• /
• v.14 no.1
• /
• pp.27-33
• /
• 2010

We investigate some operation characteristics and energy efficiency of the BLDC motor system driven by different two types power conversion method depends on same battery source for applying to electrical motor propulsion system of a small ship. Also, we suggest an estimation manner of operating performances such as total running distance and operating speed of ships from basic discharge voltage characteristics of batteries. Through some experiments, direct power conversion was better than indirect method on the view point of energy efficiency and the voltage discharge characteristics could be used as important design factor for estimating operating performances of small ships driven by electrical motors.

• Proceedings of the KIEE Conference
• /
• 1998.07b
• /
• pp.455-457
• /
• 1998

This paper designs a noise controller for the small cavity using Coefficient Diagram Method(CDM). In the small cavity system, there exist nonlinear characteristics such as uncertain-time delay and parameter variation. In the controller design of nonlinear system with uncertainty need to the higher order controller or complexity computation. The coefficient diagram is convenient implementation of the control system design method, that is utilized as a vehicle to collectively express the important features of the system and an improved version Kessler's standard form and the Lipatov stability condition of a constitutes the theoretical basis. Simultaneously, it is provided a desired specification, such as the robustness, the stability, faster response, and lower order controller. A simulation of the system with the proposed controller shows sufficient noise cancelation in small cavity.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1945-1950
• /
• 2004

In this paper, The performance of Kim-Chi refrigerator with three evaporator and one compressor was investigated in employing 55% propane and 45% isobutane (R290/R600a) refrigerant mixture as an alternative refrigerant of R134a. The drop in test was performed by varying both refrigerant charge amount and capillary tube length in order to find both the performance and reliability of a small multi-refrigeration system. As a result, Both the power consumption and COP is increased by about 15% and 10%, respectively as compared to the baseline R134a system. In addition, the propane/isobutene refrigerant mixture system took advantage of the minimization of modification and redesigning of system components because of similar thermodynamic properties with R134a such as saturation pressure, temperature, normal boiling point(NBP) characteristics

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.8
• /
• pp.387-394
• /
• 2005

This paper deals with the grid-interactive small battery energy storage system, which aims at the integration o( power quality improvement and demand side management. The main purpose of the proposed system is to achieve the peak power cutting and to compensate the current harmonics and reactive power at the point of installation on power distribution for residential homes. paper deals with the grid-interactive small battery energy storage system, In this paper, the basic principle and control algorithm is analyzed, theoretically and the design methodology of the system is discussed. To verify the proposed system, a comprehensive evaluation with theoretical analysis, simulation and experimental results for 1 KVA load capacity is presented.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.400-403
• /
• 2003

This paper presents the signal processing of the panoramic thermal warning system that detects the small target such as aircraft and helicopter from afar. We develope the all round looking thermal imaging system which can scan all the way. This system acquires the panoramic images to reconstruct the IR images by revolving head of sensor typed line sensor at high speed. For detection, where the object of interest may be small, it is sometimes difficult to specify from object and background by conventional contrast enhancement methods. Therefore we use the adaptive plateau equalization algorithm each region to improve the contrast and make the hardware system which consists of the signal processing board for real-time display. We can verify the proposed method by the computer simulation and the hardware implementation.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.16 no.28
• /
• pp.9-19
• /
• 1993

We present a production planning and control system suitable for small to medium sized, order-based companies producing special gases of small-quantity. The proposed system uses cards each of which represents individual unit of order. The components and procedure of the system are described in detail. The proposed system is easy to implement because it visualizes the amount and distribution of the received orders; and requires minimum aid of computer.