• The Journal of Korean Association of Computer Education
• /
• v.12 no.3
• /
• pp.53-62
• /
• 2009

As Information communication technology develops, requirements for new educational media and new contents gets bigger and bigger. Especially PDA is required for educational media on m-learning environment. We design and implement intra-educational contents sequencing model and educational contents sequencing model between educational contents for PDA as educational supplementary media for m-learning environment, and LMS supporting PDA. And we balanced the work load of PDA and LMS and constructed practical service platform for using PDA as educational supplementary device.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.6
• /
• pp.1530-1536
• /
• 2007

In this paper, a mobile banking system which can provide banking services is introduced. Since a PDA has excellent features like a small-size computer and provides mobility, it has been widely used by salesmen. Therefore, if general banking services can be provided with PDA by using wireless technology, it will be very useful. In addition, it is easy to develop and maintain the client software of PDA because it uses Windows-based operation systems. In this paper, a PDA banking system is introduced. The system is designed and developed based on the techniques of wireless network, security and PDA programming to be used for mobile banking and a prototype system is developed. Moreover, we used the object-oriented modeling technique, UML and Java Beans for programming.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.1080-1085
• /
• 1993

A nonlinear control algorithm for the depth control of underwater vehicles is presented. In order to consider the deadzone effect of the flow control valve, a nonlinear fuzzy logic controller (FLC) is synthesized and combined with a linear proportional-derivative-acceleration (PDA) controller, which is called, the PDA/FLC controller. And, to show the effectiveness of the PDA/FLC control system, it is compared with the linear PDA control system through computer simulation. It is found that the PDA/FLC control scheme is a suitable one to maintain the desirable depth of underwater vehicles with deadzone.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2003.05b
• /
• pp.468-471
• /
• 2003

PDA나 핸드폰 같은 이동단말기기의 빠른 보급과 이동 네트웍 서비스의 증가로 다양한 컨텐츠가 제공되고 있다. 그러나 PDA 사용자는 현재의 서비스 보다 더욱 단순한 규칙과 쉬운 사용방법을 제공하고, 실생활에 빈 번히 적용되는 컨텐츠를 원한다. 본 논문에서는 클라이언트-서버 모델을 기반으로 이동 네트웍 환경에서 식당의 음식 메뉴를 주문 예약하고, 결제 내용을 확인하는 PDA를 위한 임베디드 소프트웨어 시스템 PDA-MENU 의 설계와 구현을 기술한다 이러한 PDA 시스템은 고객의 주문 상세내용 기록, 신속한 주문확인, 고객과의 결제를 통하여 서비스의 효율성을 높이고, 운영비의 감소를 지원할 수 있으며, 재고 관리 등에 활용할 수 있다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04b
• /
• pp.751-753
• /
• 2004

PDA에서 사용하는 대부분의 CPU는 실수 연산 구성요소(float computation component)가 없는 정수(integer) CPU를 사용한다. 인공 신경망(neural network)과 같은 실수 연산이 많은 알고리즘은 PDA에서 많은 수행시간을 가진다. 본 논문에서는 이런 단점을 해결하기 위해 무선 랜(LAN)으로 연결된 Client(PDA)/Server(PC) 구조를 이용한 효과적인 문자 추출 시스템을 제안한다. Client(PDA)는 대략적인 문자 추출 결과를 JPEG으로 압축하여 전송속도를 최소화한다. Server(PC)는 Client(PDA)의 결과를 바탕으로 정밀한 문자 영역 추출을 위해, 텍스춰 분류 방법과 연결 성분 분석 방법을 이용한다. 실험에서 제안한 방법은 속도뿐만 아니라 문자 추출에서도 효과적이었다.

• Journal of Korea Multimedia Society
• /
• v.8 no.1
• /
• pp.71-78
• /
• 2005

When a PDA is used as a mobile terminal in an infrastructure network based on 802.11b standard wireless LAN, we measured and evaluated the performance of multimedia data transmission. In general, PDAs are mainly used tot receiving bulk data like multimedia data. However, while a PDA as a mobile host transfers multimedia data to a desktop PC as a fixed host in such a network, the time taken to receive data from the PC to the PDA is always longer than the time taken to send data from the PDA to the PC by at least 53%. Thus, we consider some critical factors that affect the time taken to receive Our experimental results show that with the PDA the time taken to access a file for writing is longer than the time taken to access a file for reading of to 4.11 times. In addition, a dramatic change of the site of the receiver window, from 686 bytes to 32,383 bytes, prolongs the time taken to receive. To transfer data without any inter-packet interval for the PDA and to increase the size of the TCP receive buffer will be effective in improving the delay to receive data.

• Polymer(Korea)
• /
• v.39 no.2
• /
• pp.293-299
• /
• 2015

Conductive microcellular foams consisted of polystrene (PS) and polydopamine-coated carbon nanotube (PDA-CNT) were prepared via high internal phase emulsion (HIPE) polymerization and their morphology and electrical conductivity were investigated. CNT as a conductive nanofiller was modified to PDA-CNT by coating with hydrophilic PDA on the surface of CNT to increase aqueous phase dispersion and emulsion stability. It was possible to prepare the HIPEs having higher PDA-CNT content and the resultant foams having improved conductivity due to its good dispersion. The foams showed the morphology of interconnected cell structure. As PDA-CNT content increased, yield stress and storage modulus increased and cell size reduced. The PDA-CNT content showing electrical percolation threshold was ca. 0.58 wt% and the conductivity at PDA-CNT content of 5 wt% was increased to $10^{-3}S/m$.

• Journal of Digital Contents Society
• /
• v.3 no.2
• /
• pp.211-220
• /
• 2002

It has not been long since the current form of PDA began to be used widely. The PDA, which first came out in a recognizable form in the market a decade ago, multiplying the number of users, has recently been developed in various forms. It began to make cutting-edge technology available in PDA, and to be subdivided into various forms appropriate for special purposes, which reflected the recent intense competition in the market. It included the function of mobile phone, in tandem with the original function of PDA, by which it brought about other synergy effects and corresponded with the purpose more solidly. Due to these recent changes, PDA has had a dramatically increasing number of users, as well as the wider scope of usage and practical application by introducing new technology. However, research is required in the fields of basic usage and interface. It is important to recognize that PDA is an apparatus that stores for the users contents and information suitable for them, and that responds to them in case of need. PDA therefore needs to convey what the users require more easily and speedily without errors, and to provide them with appropriate information and contents. This paper examined the extent to which the interface of PDA including the input of contents required by the user would be efficient by questionnaires. In addition, alternatives concerning a general application environment of PDA were suggested based on the result of this survey.

• Journal of KIISE:Software and Applications
• /
• v.33 no.2
• /
• pp.220-230
• /
• 2006

As the computing technique and mobile devices get developed, the demand of multimedia contents for mobile environment has been increased. The multimedia contents provided on PDA has so far been limited to the materials such as video and audio. MPEG-4 is the international standard used for supporting to properly save, communicate multimedia in formation such as video, audio, image, text and two-dimensional object, which can present various, multimedia contents by using adaptation techniques. However, since most MPEG-4 contents are not used for PDA but desktop, it seems not to be played on PDA where needs low power consumption, limited memory capability and GUI, and so on. In this paper, we propose the adaptation techniques, which can present the MPEG-4 contents on PDA, using scene composition with MPEG-4. The proposed scheme consists of three subparts: physical adaptation, variation adaptation and resource adaptation. Physical adaptation adjusts the physical difference of between the authoring environment and playback environment. Event adaptation part transforms events used for desktop to the events used for playback on PDA. The resource adaptation enables efficiency of playback to promote by using the essential information table on BIFS parser. As the proposed scheme is applied to MPEG-4 player, we see that the MPEG-4 contents are efficiently played on PDA.

• Journal of The Korean Association of Information Education
• /
• v.10 no.2
• /
• pp.209-217
• /
• 2006

For its maximum impact on the scene of school as the educational equipment, it is necessary to understand equipmental characteristics of PDA and study the basis for utilizing it educationally. In this point of view, to inquire how PDA is helpful for education more than PC, the typical educational equipment in the past, PDA-based English vocabulary learning game is developed in this study, and after that it is applied on the scene of education. The result of study showed PDA can access the content more easily than PC, and learners expressed more curiosity and expectation of PDA than PC in a recent poll. In addition, under the condition of learner's voluntary use, the present study has found that learning with PDA is helpful to enhance the academic achievement more than one with PC.