• KEPCO Journal on Electric Power and Energy
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• 제7권1호
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• pp.79-84
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• 2021

The fundamental element to be kept for big data analysis, artificial intelligence technologies and asset management system is a data quality, which could directly affect the entire system reliability. For this reason, the momentum of data cleaning works is recently increased and data cleaning methods have been investigating around the world. In the field of electric power, however, asset data cleaning methods have not been fully determined therefore, automatic cleaning algorithm of asset data for transmission cables has been studied in this paper. Cleaning algorithm is composed of missing data treatment and outlier data one. Rule-based and expert opinion based cleaning methods are converged and utilized for these dirty data.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.622-626
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• 2001

Every design activity has a goal of satisfying a set of functional requirement. The commencement of a design, therefore, must have its foundation upon the identification of the functional requirements. Many of the design practices of the industrial examples can be categorized as design of small systems that are defined to have limited and fixed sets of functional requirements to be satisfied at all times. In the case of small systems it facilitates the construction of a knowledge-based system for a specific purpose to decompose the functional requirement and map ones in the lowest level into specific design features. When the number of design features is large, they need to be managed by groups. This paper suggests a grouping method for design process can be regarded as a series of selections of the predefined functional primitives according to the requirements and the preceding selections. An intelligent product design system for automatic transmission lever design is developed as an example.

• 한국정밀공학회지
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• 제27권5호
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• pp.27-35
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• 2010

A loader used for uploading materials into truck is a kind of construction equipment. Mainly, a wheel loader is applied to construction work. Recently, an automatic transmission for the wheel loader is used to help drivers get the repetitive works done comfortably. It is composed of geartrain, clutch pack, hydraulic control system and TCU. Especially, a high-performance proportional control valve and its control algorithm is demanded to achieve the shift quality during a change of speed. In this paper, the commercial package program was used in order to justify model of the proportional control valve and simulate it. Steady-state and dynamic characteristics of PCV were analyzed to classify attractive forces and hydraulic control characteristics. This model also was verified the validity compared to the experimental result. Using the developed model, performances of PCV were predicted as studying design parameters.

• 한국자동차공학회논문집
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• 제15권4호
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• pp.41-46
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• 2007

This article deals with the design and prototyping of Shift-By-Wire system for an automatic transmission equipped vehicle. In order to manipulate the shifting action electronically, Shift-By-Wire system consists of an electronic shift lever, an electric shift actuator and position sensors. The shift lever is designed to transform the driver's shifting command into an electric signal; it includes the position sensor using non-contact type hall sensor and an additional shifting switch acting as Tip-tronic. For the design of an electric shifting actuator, we investigated the stroke angles and shifting efforts of the manual control lever in each shifting section. And the position sensor of the shifting actuator is designed by using a potentiometer with an optical encoder. Finally the prototype of Shift-By-Wire system was built in a conventional 2.4L class SUV vehicle, and we performed road tests in order to verify its performance.

• 한국정밀공학회지
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• 제21권2호
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• pp.52-59
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• 2004

In this paper, the automatic system generation algorithm based on the element combination algorithm discussed in the first part of this paper for designing an arbitrary type of the automatic transmissions is proposed. The powertrain design software using these algorithms is developed. This automotive powertrain design software with user-friendly graphic user interface has two main modules. The first module, the automatic power flow generation module, is already discussed in the previous paper. The second module dealing with the automatic system generation algorithm is discussed in this paper. The power-flow simulation software fur the arbitrary type of powertrain is then developed. The simulation and experimental results of the vehicle equipped with two planetary gear type automatic transmission are compared to validate the proposed algorithms and developed software. The simulation results demonstrate the good agreement with the experimental results.

• 유공압시스템학회논문집
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• 제6권1호
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• pp.10-16
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• 2009

Automatic power transmission systems consisted of a torque converter and several planetary gear sets, clutches and brakes are controlled by a hydraulic shift control circuit and an electronic transmission control unit. The hydraulic circuit serves for the operation of the torque converter and lubrication oil supply of the transmission system as well as for the actuation of clutches for the automatic gear shift. The complicated hydraulic control circuit constructed by many spools, solenoids, orifices and flow passages are integrated into one small valve block and it is powered by one hydraulic pump. In this paper, a test equipment was developed to measure the oil consumption of each component at various wide operating conditions. Test data about 730 sets acquired from five test items are analyzed and discussed on the oil capacity of the circuit.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.19-23
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• 2009

This paper focuses on vehicle fuel economy improvement using D-Range neutral control of automatic transmission. The system objected to reducing of fuel consumption during idle. Usually, turbine of conventional auto transmission is mechanically linked to wheel during idling condition. Therefore speed ratio of torque converter is zero for that period. This causes needless power loss by the torque converter slip. To improve this inefficiency automobile makers develops electronically-controlled D-range neutral control system. The D-range neutral control system minimizes slip on the torque converter by shifting gear to a neutral position during vehicle stoped with D-range gear position. However there's insufficient study about the effect of D-range neutral control system on vehicle fuel economy. In this paper, researches are performed on effect of D-range neutral control system on vehicle fuel economy by experiment with two different vehicle. And it is also estimated the effect on vehicle fuel economy using computer simulation. As a result, 1.8% of LA-4 mode fuel economy improvement can be achieved in a vehicle by D-range neutral control system.

• 한국생산제조학회지
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• 제24권6호
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• pp.675-681
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• 2015

When many holes on a plane are machined simultaneously, the positional precision and machining efficiency are very important. Multi-spindle heads are typical order making products of which the number of shafts and hole positions vary depending on the size or form of the product. For the automatic design of multi-spindle heads, the design modules for power transmission systems for drive, idle, and spindle shafts were developed, and a design technique the determining the optimum position and number of idle shafts according to gear positions was developed. In addition, for the precise determination of the multi-spindle head, the design methods for the guide planes of columns, and feed mechanisms were devised. In addition, the design modules for accurate clamping and automatic transportation mechanisms were developed. Finally, in order to simplify and standardize the design process, the design analysis and simulation verification modules are integrated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1790-1795
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• 2000

송전선로에 새로운 Spacer damper를 설계하는데 이 논문의 목적이며, 이 설계되는 새로운 Spacer damper는 매우 중요한 특징과 장점을 가지고 있다. 또한, 최근 Spacer damper의 문제가 프랑스, 일본 등 다른 나라에서도 자동화 시스템과 함께 많이 발전되어 왔다. 개발된 Spacer damper외 설치는 특별한 기기없이 설치가능하며, 최근 자동 클램핑 장치 이용한 Spacer damper가 도입되어 피로 파괴와 미풍진동에 매우 효과적임이 입증되었고 보수유지가 거의 필요없으므로 경제성도 높으나 고가의 수입가격으로 인해 국산화의 필요성이 절실하다.

• 한국정밀공학회지
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• 제14권12호
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• pp.95-104
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• 1997

We consider controller design problem to enhance shift quality for automatic transmission. A dynamic modeling related to shifting (mainly 2-3 up-shift) is constructed and nonlinear robust controllers are designed to reduce output torque during shifting. Suggesting a new hydraulic circuit enabling the direct clutch drive, the control activity is extended and more implementable than the conventional design. The designed robust controllers overcome the unmodeled dynamics and the uncertainty embending in the system. Moreover, the dynamic effect between the clutch pressure and the PWM valve duty is considered via singular perturbation technique.