• Educational Technology International
• /
• 제16권1호
• /
• pp.31-57
• /
• 2015

This study aims to understand the overall experiences of students who use notebook computers in class by using a qualitative approach. Interview data were collected from 23 Korean college students at a Korean university, who use notebook computers in their classes; the data were analyzed through the constant comparison method. The results from this study can be categorized into two themes: the positive and negative effects of using a notebook computer in class, and different perspectives on the effects of using a notebook computer in class. The positive effects of notebook computer usage were specified as production of lecture notes, performing searches for information, management of learning materials, and effective time management. However, behaviors such as perusing other works not associated with the class were indicated as negative effects. The participants had different perceptions about the effect of notebook computer usage in increasing academic performance, although they were satisfied in their experience with notebook computers in general. These results imply that appropriate methods of technology usage are needed and that the support of an instructor is essential to achieve fully beneficial use of notebook computers in class.

• 유통과학연구
• /
• 제6권1호
• /
• pp.99-116
• /
• 2008

본 연구는 기업환경이 디지털화 되어가는 상황에서 영업사원의 노트북 사용이 서비스공정성과 고객만족을 매개변수로 하여 영업사원평가에 어떤 영향을 주는지에 대해 연구하였다. 연구결과 첫째, 영업사원의 노트북사용은 서비스공정성에 영향을 미치는 것으로 나타났다. 둘째, 서비스공정성 중에서 절차공정성과 상호작용공정성은 고객만족에 긍정적 영향을 미치지 못하는 것으로 확인되었고 분배공정성은 고객만족에 긍정적인 영향을 주는 것으로 확인되었다. 셋째, 고객만족은 영업사원 평가에 영향을 미치고 있음을 확인하였다. 넷째, 영업사원의 노트북 사용은 영업사원평가에 직접적인 영향을 미치지 않음을 확인하였다. 그러나 결과에서 보듯이, 영업사원의 노트북 사용은 서비스공정성과 고객만족을 통해 영업사원평가에 유의한 영향을 주는 것으로 나타났다.

• Environmental Engineering Research
• /
• 제11권1호
• /
• pp.14-27
• /
• 2006

The proper management of discarded electronic devices (often called electronic-waste) is an emerging issue for solid waste professionals throughout the world because of the large growth of the waste stream, and the content of toxic metals in them, most notably heavy metals such as lead. Notebook computers are becoming one of the major components of discarded computer devices and will continue to increase in the waste stream in the future. While the computers hold great promise for recycling, a substantial amount of this waste is often disposed in municipal solid waste (MSW) landfills. The toxicity characteristic leaching procedure (TCLP) is commonly used to simulate worse case leaching conditions where a potentially hazardous waste is assumed to be disposed along with municipal solid waste in a landfill with actively decomposing materials overlying an aquifer. The objective of this study was to examine leaching potential of lead from discarded notebook computers using the scale-up TCLP, other standard leaching tests such as California waste extraction test (Cal WET), and the synthetic precipitation leaching procedure (SPLP) and actual landfill leachates as leaching solution. The scale-up TCLP is a modified TCLP (where the device was disassembled and leached in or near entirety) to meet the intent of the TCLP. The results showed that the scale-up TCLP resulted in relatively high lead found in the leachate with an average of 23.3 mg/L. The average level was less than those by the standard TCLP and WET (37.0 mg/L and 86.0 mg/L, respectively), but much greater than those by the SPLP and the extractions with the landfill leachates (0.55 mg/L and 1.47 mg/L, respectively). The pH of the leaching solution and the ability of the organic acids in the TCLP and WET to complex with the lead were identified as major factors that controlled the amount of lead leached from notebook computers. Based on the results obtained by a number of leaching tests in this study, notebook computers may present a potential leaching risk to the environment and human health upon land disposal. However, further investigation is still needed to assess the true risk posed by the land disposal of discarded notebook computers.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2010년도 하계학술대회 논문집
• /
• pp.13-14
• /
• 2010

The active clamp forward converter provides zero voltage switching and low voltage stress in wide input voltage range. It has a high efficiency at a high switching frequency and the clamped energy is recovered to the input stage. It is available for the power adaptor circuit of notebook computer. The adaptor with 19.5V/200W output power is designed for notebook computer. Specially, it is considered the transformer properties of the converter in design process. The organized process is checked by the validity from the test of the active clamp forward converter.

• 전기학회논문지
• /
• 제56권8호
• /
• pp.1418-1423
• /
• 2007

The topology of LLC half bridge resonant converter provides ZVS characteristic. The voltage stress and current stress are smaller than that of the general resonant converters. So the LLC HB resonant converter can be considered as a optimal circuit for the notebook computer adapter. In the adapter design, we should consider the weight, the size and the overheat of the adapter. Thus the higher efficiency is an essential particular. First of all, the optimal design of transformer is the most important facts. Some parameters should be considered in order to get the highest efficiency. The adapter is designed through the considering of these parameters including the PFC circuit as the pre-regulator. It converts AC line input into about DC 390V link voltage of the LLC HB converter input and the converter has 16V/90W ratings. The efficiency measured is about up to 93%.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.273-277
• /
• 1999

A cold cathode flourescent lamp for the backlight in the notebook computer requires high input voltage about 1300(V) when it turns on. But once a discharge starts, the input voltage can be dropped by about one-third for continued output. The equivalent impedance also varies from open to several dozens of kilo-ohms. The piezoelectric transformer converts electrical energy into mechanical energy and then converts it back to electrical energy at a high voltage. Its high output voltage, high efficiency and small size are suitable for driving the LCD backlight in the notebook computer. The piezoelectric transformer operates near the resonance frequency and the output waveform is close to sine wave with very little noise. This paper suggests an inverter for LCD backlight of notebook computer using piezoelectric transformer that includes voltage to frequency converter for gate signal which is useful for tracking of variable resonance frequency depending on load impedance.

• Industrial Engineering and Management Systems
• /
• 제6권2호
• /
• pp.146-157
• /
• 2007

This paper discusses two algorithms for recommending notebook computer (NBC) and workstation adjustments so that the user can assume an ergonomic seated posture during NBC operation. Required input data are the user's anthropometric data and physical dimensions of the NBC and the workstation. The first algorithm is based on an assumption that there are no workstation constraints while the second algorithm considers the actual seat height and work surface height. The results from the algorithms include recommendations for adjusting the NBC (tilt angle of the NBC base unit, angle between the base and screen units, and base support height) and the workstation (heights of seat support and footrest, and distance between the body and the NBC).

• 산업경영시스템학회지
• /
• 제18권33호
• /
• pp.71-77
• /
• 1995

In management contexts, mathematical programming is usually used to evaluate a collection of possible alternative courses of action on route to selecting one which is best. Using an application of linear programming known as Data Envelopment Analysis(DEA), a method is described to compare products which vary in excellence along a number of dimensions, and for each of which there might be a number of associated "costs". This paper is illustrated by comparing published benchmarks of notebook computers. Potential uses of a DEA analysis of products might be to assist corporate buyers who may need to reconcile a diversity of present and future uses in one standardised purchase; in competitor analysis; and as a normative model of product excellence against which product purchasing behavior could be compared. compared.

• 디지털융복합연구
• /
• 제13권1호
• /
• pp.289-295
• /
• 2015

연구개발정보를 체계적으로 기록하고 관리하는 것이 연구개발 품질을 확보하기 위한 기본적인 방법이며 더 나아가 프로젝트를 성공적으로 수행하기 위한 밑거름이 된다. 특히, IT 기술의 발달로 인해 연구실 환경이 디지털화 됨에 따라 대부분의 연구개발정보가 전자문서로 기록되고 있다. 본 연구에서는 연구개발정보를 체계적으로 기록하고 관리하기 위해 도구로 사용되는 전자연구노트에 대해 살펴보고 연구환경에 맞는 모델을 제시하고자 한다.

• 한국전자파학회논문지
• /
• 제23권6호
• /
• pp.716-722
• /
• 2012

본 논문에서는 WWAN 대역의 노트북 안테나와 LCD 구동 모듈 간의 전자기 간섭이 노트북의 무선 통신에 끼치는 영항을 분석하고, 이러한 간섭을 줄이기 위한 대책을 논의하였다. LCD 구동 모듈에 의한 잡음원을 모의하기 위해 다중 대역 안테나를 설계, 제작하였고, 이를 사용하여 노트북 내에서 전자기 간섭에 의한 효과를 시뮬레이션 및 모델 실험을 통해 분석하였다. 그 결과, 노트북의 구조에 기인한 특정 주파수 대역에서 더 많은 잡음이 전달될 수 있음을 확인하였다. 또한, 구조물 변화에 의한 잡음 전달의 감소를 위해 구조물에 격벽을 세우고, 그 크기를 변경하며 전자기 간섭을 분석하였으며, 이러한 구조 변경이 통신 대역 내의 전자기 간섭을 감소시킬 수 있음을 보여주었다.