• 한국정밀공학회지
• /
• 제16권1호통권94호
• /
• pp.75-86
• /
• 1999

In the assembly system, a pallet plays an important role of transfer and storage. As products become various, many different pallets are also necessary. Since some of them are redundant, a design of pallet with high flexibility is important. This paper suggests design alternatives, in designing pallets with high flexibility. The purpose of this study is to rationalize assembly process of mid-small size products. Every pallet has suitability values depending on characteristic factors of a product, and this value is determined by using AHP (Analytic Hierarchy Process) technique. As the characteristic factors of a product are changed, the suitability value is also changed. Design alternatives can be found by tracing change of the suitability value, which are based on correlation between the characteristic factors of a product and a pallet element.

• 전력전자학회논문지
• /
• 제9권1호
• /
• pp.25-29
• /
• 2004

본 연구는 최근 관심이 높아지고 있는 스위치드 릴럭턴스 전동기(SRM)를 적용한 소형 지게차의 구동시스템 개발에 관한 연구이다. SRM은 스위칭 전원에 적절한 전동기구로서, 전력전자기술의 발달에 힘입어 최근 연구가 활발히 이루어지고 있다. 본 연구에서는 기존 소형 전기지게차에 사용되어지고 있는 직류직권 전동기를 경제적이고 고효율, 견고성, 넓은범위의 속도제어가 가능한 스위치드 릴럭턴스 전동기(Switched Reluctance Motor, 이하 SRM)로 대체하기 위해 저전압용 전동기를 설계하고 이 전동기를 구동하기 위한 구동 시스템을 개발하였다. 또한 실제 전기 지게차에 적용하기 위하여 구동시스템의 운전특성을 확인하였다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1334-1337
• /
• 2007

A steel pallet to carry lighter logistic articles is developed based on the DFSS(design for Six Sigma) methodology. Combining the conventional DFSS(Design For Six Sigma) methodology with that of VE(Value Engineering) is the novel feature of this paper to achieve maximum cost reduction. In this paper, systematical steps to achieve the required structural spec's are presented by conventional DMEDI(Define-Measure-Explore-Develop-Implement) process. To imply the target costing, evaluation of functions consisting of the pallet has been performed by value methodology. Then best design concept is selected in the Explore step, following structural optimization utilizing FEM. Finally the performance of prototype is investigated by pilot test in the Implement step. The developed steel pallet is being commercialized in the fields of automated ware house.

• 한국포장학회지
• /
• 제26권1호
• /
• pp.11-17
• /
• 2020

This study conducted a case study and a questionnaire analysis in parallel. In the case study, a study was conducted on domestic manufacturer A by analyzing pallet loading efficiency of RRP(Retail Ready Packaging) products and pallet loading efficiency of MWC(Membership Wholesale Club) delivered products. As a result of the pallet loading efficiency simulation of 50 RRP products of Manufacturer A, it was 80.0% based on the T-11 type pallet and 84.3% based on the T-12 type pallet. It was found It refers that the route of producing the product from the manufacturer A and delivering it to the MWC A in the form of RRP resulted in the decrease of the pallet loading efficiency through the change of the loading pattern and the adjustment of the number of loads. As a result of analyzing the questionnaire about whether the overall efficiency of the supply chain will be improved if the operation of the packaging system considering the SCM(Supply Chain Management) aspect is χ² = 178.500, there was a statistically significant difference at the significance level of 0.000. Manufacturers and logistics companies answered "yes" the most, but distributors answered "is average" the most, confirming that the packaging can be constructed with the highest operational efficiency. Therefore, as a result of confirming the impact of packaging design considering the SCM aspect on logistics efficiency, it indicates the importance of closer collaboration between manufacturers and distributors.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2010년도 추계학술발표논문집 1부
• /
• pp.76-79
• /
• 2010

본 논문에서는 고 효율 및 고 출력 특성을 가지는 질화갈륨(GaN) 소자를 이용하여 WiMAX 및 LTE System에 사용될 수 있는 DPD용 Pallet Amplifier를 제작하였다. 제작된 Pallet Amplifier는 Pre-drive로써 저 전류의 MMIC를 채택하고, Drive 단과 Main 단에 15W 급과 30W 급의 질화갈륨 소자를 사용 하였으며, 추가적인 효율 개선을 위해 PCB상에 Doherty Structure를 적용함으로써 보다 높은 효율을 구현하였다. 제작된 Pallet Amplifier는 음 전원 Bias 제어 회로, 온도에 따른 Gain 보상회로, Sequence 회로 및 Main 전원 Drop에 따른 보호 회로를 구현하였다. WiMAX Signal을 이용한 Modulation Power 10Watt Test에서 약 36.8~38.3%의 Pallet 효율과 DPD Solution인 TI GC5325SEK DPD Board 사용 시 ACLR은 약 46dBc 이상을 가지는 것으로 측정되었다. 본 논문에서 제작된 Pallet Amplifier는 Upper Band와 Lower Band로 나누어 제작되었던 기존 Pallet Amplifier와 달리 하나의 Pallet Amplifier로 2496~2690MHz에서 모두 사용하면서 종전에 사용되고 있는 Pallet Amplifier에 비해 Size가 최소 10% 이상 축소되어 효율 및 크기 면에서 종전 Pallet Amplifier보다 큰 이점을 갖는다.

• 파렛트 뉴스
• /
• 통권33호
• /
• pp.1-13
• /
• 2004

• 한국군사과학기술학회지
• /
• 제13권6호
• /
• pp.1071-1079
• /
• 2010

This paper describes the design and fabrication of a high-efficiency GaN HEMT(Gallium Nitride High-electron Mobility Transistor) Pallet power amplifier module for S-band phased array radar applications. Pallet amplifier module has a series 2-cascaded power amplifier and the final amplification-stage consists of balanced GaN HEMT transistor. In order to achieve high efficiency characteristic of pallet power amplifier module, all amplifiers are designed to the switching-mode amplifier. We performed with various PRF(Pulse Repetition Frequency) of 1, 10, 100 and 1000Hz at a fixed pulse width of $100{\mu}s$. In the experimental results, the output power, gain, and drain efficiency(${\eta}_{total}$) of the Pallet power amplifier module are 300W, 33dB, and 51% at saturated output power of 2.9GHz, respectively.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
• /
• pp.231-234
• /
• 2004

This paper is to research about design and drive system of a switched reluctance motor for a pallet truck application. SRM is suitable for a pulse type source and is researched for home and industrial applications owing to the advance of power electronics technology. An SRM for a pallet truck drive is developed and tested. The drive system has to operate with low voltage and high current. The small size, robustness and high efficiency make it possible to replace with DC motor which is used in a pallet truck conventionally. Test results show that pallet truck with SRM has better drive characteristics than that of the DC motor.

• Steel and Composite Structures
• /
• 제3권5호
• /
• pp.307-320
• /
• 2003

This paper presents an efficient approach to the determination of the buckling loads of down-aisle, spliced, unbraced, pallet rack structures subjected to vertical and horizontal loads. A pallet rack structures is analysed by considering the stability equations of an equivalent free-sway column. The effects of semi-rigid beam-to-upright, splice-to-upright and base-plate-to-upright connections are fully incorporated into the analysis. Each section of upright between successive beam levels in the pallet rack is considered to be a single column element with two rotational degrees of freedom. A computer algebra package was used to determine modified stability equations for column elements containing splices. The influence of the position of splices in a pallet rack is clearly demonstrated.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제54권11호
• /
• pp.511-518
• /
• 2005

This paper presents the design and drive characteristics of a switched reluctance motor for an electric power pallet vehicle. The designed switched reluctance motor is redesigned by using the finite element analysis(FEA) as a variation of the pole-arc angle for the purpose of an electric power pallet vehicle performance. The output power and torque characteristics of a switched reluctance motor are variable by switching angles of the commutator. Therefor this paper is studied about relationship between the output power and torque characteristics of a switched reluctance motor according to switching angles. The output power of the characteristic point of an electric power pallet vehicle has been shown by experiment. The designed motor drive system operates with the low voltage and high current with using the battery. The core and frame temperatures were described. In this paper, the designed motor is shown better drive characteristics than the DC motor from the rated to maximum, which is verified by the finite element analysis and experimental results.