• Educational Technology International
• /
• v.16 no.1
• /
• 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.

• Journal of Distribution Science
• /
• v.6 no.1
• /
• pp.99-116
• /
• 2008

This research is focused on the effects of salesperson's evaluation of using the notebook computer. From analysis of the resulting data, using the notebook computer are increased the quality of salesperson's service-justice. Salesperson's distributive-justice affects to positive the customer satisfaction. But procedural justice and interactional justice cannot affect to positive the customer satisfaction. Maybe, I think that the reason will be a feature of insurance goods. And customer satisfaction affects to positive the salesperson's evaluation. But, only using the notebook computer cannot affect to positive the salesperson's evaluation. According to the result, using the notebook computer of salesperson affects to positive the salesperson's evaluation mediate of the service justice and customer satisfaction. There are limitations on generalization due to the results based on only insurance industry, but this study will be a useful exploratory step before designing a future survey.

• Environmental Engineering Research
• /
• v.11 no.1
• /
• 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.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• 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.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.8
• /
• 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%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• 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
• /
• v.6 no.2
• /
• 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).

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.18 no.33
• /
• 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.

• Journal of Digital Convergence
• /
• v.13 no.1
• /
• pp.289-295
• /
• 2015

Laboratory Research Notebook is the recorded data of the process and the result of research and also the most basic data. To record and manage R&D information systematically is a very basic method to secure R&D quality and becomes a foundation of performing a project successfully. Especially, as the laboratory environment is getting digitalized due to development of IT technology, most R&D information is recorded as electronic documents. Therefore, Laboratory Research Notebook is used to effectively manage R&D information recorded as electronic documents. This study would like to look at Laboratory Research Notebook which is used to manage R&D information systematically and then present a model which suits research environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.6
• /
• pp.716-722
• /
• 2012

In this paper, we analyzed the RF interactions between WWAN antennas and an LCD driving module inside the cover of a notebook computer, and discussed reduction method of RF coupling. In order to simulate the RF noise source from the LCD driving module, a multi-band antenna was designed and used with a simplified notebook model to test the RF coupling phenomena. We verified that the RF noise coupling is enhanced at certain frequencies due to cavity structure formed inside the notebook computer. Also, we showed that conductive barrier walls, which are inserted inside the notebook, could be effective in reducing RF coupling.