• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권3호
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• pp.134-138
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• 2005

A typical conventional systems of a linear motion use rack and pinions or ball screws to convert rotary motions from DC servo motors. A linear motor has been used a several field for a MEMS technology and a aircraft carrier. We have studied a transient response of a linear actuator with a damping ratio, spring constant and a pressed power for a constant stroke control.

• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.62-68
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• 2002

To satisfy the requirement of the one axis linear positioning system, which is following control of the desired trajectory without following error and is the high positioning accuracy, feed-forward loop having cogging force model is proposed. In the one axis linear positioning system with linear PM motor, cogging force acting as disturbance is modeled analytically. Analytic model of cogging force is verified by result measured from positioning system constructed with linear PM motor. Measured result is very similar with proposed analytic model. Cogging force model is used as feet forward loop in control scheme of linear positioning system. Cogging force feed-forward'loop is obtained from analytic model of cogging farce. Trajectory following error is reduced from 300nm to 100nm by applying the proposed cogging farce feed-forward loop. By using analytic model of cogging force, the control scheme is simplified. Also this analytic model is applicable to calculation of characteristic value of positioning system in design process.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.131-133
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• 2010

As linear scheduling method has been used since 1929, Empire State Building linear schedule, it is being applied in various fields such as construction and manufacturing. When addressing concurrent critical path occurring on linear schedule of construction, the empirical researches stress the resource management which should be applied for optimizing work flow, flexible work productivity and continuos resource allocation. However, work relationships has been usually overlooked for making the linear schedule from existing network schedule. Therefore, this research analyze the previous researches related to linear scheduling model and then propose the method that can be applied for adopting the relationships of network schedule to the linear schedule.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.587-592
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• 2009

This paper is concerned with the development of linear magnetic actuator for active vibration control. The newly developed linear magnetic actuator consists of permanent magnets and copper coils. On the contrary to the voice-coil type actuator, the linear magnetic actuator utilizes magnetic flux to generate the shaft movement. In this study, experiments on the prototype linear magnetic actuator were carried out to investigate its dynamic characteristics. Block and inertia forces generated by the actuator were measured. The experimental results show that the actuator can be used as both actuator and active tuned-mass damper. The linear magnetic actuator was attached to a cantilever as the active-tuned mass damper and active vibration control experiment was carried out. The experimental results show that the newly developed linear magnetic actuator can be effectively used for the active vibration control of structures.

• ETRI Journal
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• 제39권1호
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• pp.108-115
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• 2017

ARIA is a 128-bit block cipher that has been selected as a Korean encryption standard. Similar to AES, it is robust against differential cryptanalysis and linear cryptanalysis. In this study, we analyze the security of ARIA against differential-linear cryptanalysis. We present five rounds of differential-linear distinguishers for ARIA, which can distinguish five rounds of ARIA from random permutations using only 284.8 chosen plaintexts. Moreover, we develop differential-linear attacks based on six rounds of ARIA-128 and seven rounds of ARIA-256. This is the first multidimensional differential-linear cryptanalysis of ARIA and it has lower data complexity than all previous results. This is a preliminary study and further research may obtain better results in the future.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.785-790
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• 2001

Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools, because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force are measured and analyzed. To improve the thermal stiffness of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented.

• 한국정밀공학회지
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• 제19권3호
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• pp.123-130
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• 2002

Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force measured and analyzed. To improve the thermal characteristics of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented.

• 정보학연구
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• 제5권1호
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• pp.133-142
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• 2002

본 논문에서는 linear window operator의 효율적인 구현 방안을 제안하였다. 블록 상태 공간함수를 이용하여 computational primitive를 찾아내고 이를 이용하여 프로세사의 datapath의 구현에 사용함으로서 효율적인 linear window operator의 구현을 가능하게 하였다. 또한 linear window operator의 실시간 처리를 위하여 데이터 분할 기법을 사용한 다중 프로세서 구조를 제안하였다. 블록의 크기에 따른 성능 분석을 통하여 제시된 프로세서 및 다중 프로세서의 성능이 우수함을 보였다.

• Journal of applied mathematics & informatics
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• 제35권1_2호
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• pp.165-180
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• 2017

In this study, Taylor matrix algorithm is designed for the approximate solution of linear and non-linear differential equation systems. The algorithm is essentially based on the expansion of the functions in differential equation systems to Taylor series and substituting the matrix forms of these expansions into the given equation systems. Using the Mathematica program, the matrix equations are solved and the unknown Taylor coefficients are found approximately. The presented numerical approach is discussed on samples from various linear and non-linear differential equation systems as well as stiff systems. The computational data are then compared with those of some earlier numerical or exact results. As a result, this comparison demonstrates that the proposed method is accurate and reliable.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.363-368
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• 2004

Due to various advantages over the conventional linear motion device such as ball-screw, linear motors have been used in wide variety of industrial applications for years. Driven by increased demand for precision machine tools, the importance of high positioning accuracy, high stiffness and high thrust are greatly increasing. The merits of linear motor are high speed, high acceleration and good positioning accurcy. In addition, Linear motor for high quality machine tool call for high thrust, high stiffness. In this paper, thrust ripple, detent force and thermal behavior are considered for the development of high performance linear motor whose thrust is up to 10,000N. This paper presents a comprehensive study for an iron core type linear motor characteristics that include the influence of PM position on thrust, thrust ripple by detent force and motor dynamics as well.