• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.47-50
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• 2000

Recently many efforts on the development of automatic processing system for delivery sequence sorting have been performed in ETRI , which requires the use of postal 4-state bar code system to encode delivery points. The 4-state bar code called postal 4-state bar code for high speed processing that has been specifically designed for information processing of logistics and automatic processing of the mail items. This paper describes a method of Reed-Solomon encoding for creating error correction codeword of 4-state bar code.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1027-1030
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• 1999

Recently many efforts on the development of automatic processing system for delivery sequence sorting have been performed in ETRI, which requires the use of postal 4 state bar code system to encode delivery points. This paper addresses the issue on the reduction of reading error in postal 4 state raster beam based bar code reader by adjusting measured values of bar code width to its average value over each interval. The test results show that the above method reduces the average reading error rate approximately by 90-100%.

• The Transactions of the Korea Information Processing Society
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• v.7 no.7
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• pp.2149-2160
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• 2000

Recently many efforts on the development of automatic processing system for delivery sequence sorting have been performed in ETRI, which requires the use of postal4-state bar code system to encode delivery points. The 4-state bar code called postal 4-state barcode for high speed processing that has been specifically designed for information processing of logistics and automatic processing of he mail items. The Information of 4-state bar code indicates mail data such as post code, delivery sequence number, error correction code worked, customer information, and a unique ID. This appear addresses the issue on he reduction of reading error in postal 4-state raster beam based bar code reader. The raster beam scanning features are the unequally distributed number of spots per each unit, which cause reading errors. We propose a method for reducing the bar code reading error by adjusting measured values of bar code width to its average value over each interval. The test results show that the above method reduces the average reading error rate approximately by 99.88%.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.146-155
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• 2000

This paper describes a 4-state bar code called HANGUL 4 ST that has been specifically designed for automatic processing of the letter mails, A HANGUL 4 ST bar code is a necessary data base that is applied data capture and data carrier with it all the information necessary for sorting, the amount capture for transportation of mail items, and valued-added services such as indicia, tracking and trace. The 4-state bar code information contents are composed of a postal code, delivery point, customer information including customer identification number and name, and parity bits for error detect and correct. The data density capability of HANGUL 4 St allows all useful sorting data and customer data to be encoded on one label. This supports better automatic processing in mail items, higher level of customer service and more efficient operation.

• The KIPS Transactions:PartD
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• v.8D no.3
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• pp.285-294
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• 2001

Recently many efforts on the development of automatic processing system for delivery sequency sorting have been performed in ETRI, which requires the use of postal 4-state bar code system to encode delivery points. This paper addresses the issue on the extension of read range and the improvement of image processing method. For the improvement of image processing procedure, applied information acquisition method through basic two thresholds onto the horizontal axial line of gray image based on reference information of 4-state bar code symbology. Symbol values are computed after creating two threshold values based on the obtained information through search of horizontal axial values. The implementation result of 4-state bar code reader are obtained the symbol values within 30~60 msec (58,000~116,000 mail item/hour)without noise removal or image rotation in spite of the incline $\pm 45^{\circ}$.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.934-938
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• 2003

Flow analyses using FLUENT 5.4 code were performed to validate the application of the local bidirectional flow tube in case of water and air flow. In this study, sensitivity studies have been performed to optimize the design features of the bi-directional flow tube which can be applied for the various experimental conditions. 2-dimensional axisymmetric steady state flow analyses have been performed. By calculating the differential pressure at both the front and the rear hole of the flow tube, K values were evaluated. The K values show good linearity regardless of the tube sizes and the Re numbers in both water and air flow. And system pressure and water subcooling didn’'t affect the K values. Under the elevated pressure of 80bar with 80K water subcooling, the K value indicates a similar trend with the case of 2bar with 80K water subcooling.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.846-851
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• 2000

4-state 바코드의 정보는 우편번호, 배달순서코드, 고객 정보 등을 수록되며, 판독율 향상을 위한 오류정정 코드워드를 적용할 수 있다. 이 4-state 바코드는 우편물 자동구분처리의 효율화 및 우편물류의 정보표현, 전달, 처리를 효율적으로 지원되도록 개발하고 있다. 본 논문은 우편물 접수 및 처리과정에서 필요로 하는 4-state 고객 바코드 인쇄규격 검증 및 판독시스템 개발에 관한 것으로 4개의 높이로 구성된 바들의 특성과 바의 두께 및 공간 값이 균일한 간격으로 바가 인쇄되는 특징을 고려하여 Laser Diode 배열방법을 적용하였다. 또한, 우편물을 자동으로 이송시키고, 일정한 영역에 배열한 Laser Diode에 의하여 바의 두께, 공간, 높이 값을 정확하게 판독될 수 있도록 한 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.433-436
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• 2000

우편물 자동구분 처리의 범위를 확장시키기 위하여 집배원의 배달순서로 구분하기 위한 방법이 요구된다. 이는 우편 자동구분처리를 위하여 우편봉투에 인쇄된 주소 및 우편번호를 인식하고 이에 대응하는 자동구분정보를 우편물상에 바코드 인쇄하고 판독하여 구분하게 된다. 또한, 다량우편 이용자들에 의하여 우편물 상에 고객 바코드가 사전에 인쇄된 경우에는 바코드를 판독하여 구분한다. 본 논문에서는 우편물 자동구분 처리를 위하여 적용될 4-state 바코드에 정보수록 밀도를 향상시키기 위한 방법을 적용한 것이다. 시험 결과에 의하면, 4-state 바코드의 정보수록밀도는 기존의 16.67% 보다 약 27.79% 향상시킬 수 있었다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.331-333
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• 2001

문자인식 기술에 의해 우편번호와 주소를 인식하고 4-state 바코드를 인쇄하여 배달순서로 자동구분하기 위한 연구가 진행되고 있다. 이 4-state 바코드를 사전에 인쇄하여 접수될 경우에는 바코드의 인쇄규격 및 수록된 정보의 검증이 요구된다. 본 논문에서는 이미지에 의하여 4-state 바코드를 인쇄규격 검증을 위하여 심볼의 두께 및 공간 값이 정확한 값이 획득, 심볼의 훼손상태, 기울기 값, 수록된 정보인 우편번호와 배달순서 코드를 검증할 수 있도록 한 것이다. 시험결과에 의하면 소형통상 우편물 1통에 대하여 인쇄규격 검증을 위한 소요시간을 30~60msec 이내에 가능하게 되었다.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.3
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• pp.7-18
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• 2022

Secondary batteries used in electric vehicles have a potential risk of ignition and explosion. Various safety measures are being taken to prevent these risks. A numerical study was performed using a computational fluid dynamics code on the cases where pressure relief vents that can reduce the blast overpressures of batteries were installed in the through-compression test room, short-circuit drop test room, combustion test room, and immersion test room in facilities rleated to battery used in electric vehicles. This study was conducted using the weight of TNT equivalent to the energy release from the battery, where the the thermal runaway energy was set to 324,000 kJ for the capacity of the lithium-ion battery was 90 kWh and the state of charge (SOC) of the battery of 100%. The explosion energy of TNT (△H_TNT) generally has a range of 4,437 to 4,765 kJ/kg, and a value of 4,500 kJ/kg was thus used in this study. The dimensionless explosion efficiency coefficient was defined as 15% assuming the most unfavorable condition, and the TNT equivalent mass was calculated to be 11 kg. The internal explosion generated in a test room shows the very complex propagation behavior of blast waves. The shock wave generated after the explosion creates reflected shock waves on all inner surfaces. If the internally reflected shock waves are not effectively released to the outside, the overpressures inside are increased or maintained due to the continuous reflection and superposition from the inside for a long time. Blast simulations for internal explosion targeting four test rooms with pressure relief vents installed were herein conducted. It was found that that the maximum blast overpressure of 34.69 bar occurred on the rear wall of the immersion test room, and the smallest blast overpressure was calculated to be 3.58 bar on the side wall of the short-circuit drop test room.