• Title/Summary/Keyword: digital appliance

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Solubility Consideration in Performance Analysis of a $CO_2$ Twin Rotary Compressor (오일 용해도를 고려한 $CO_2$ 트윈 로타리 압축기 성능해석)

  • Kim, Woo-Young;Ahn, Jong-Min;Kim, Hyun-Jin;Cho, Sung-Oug
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.12
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    • pp.842-849
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    • 2007
  • For a $CO_2$ two-stage twin rotary compressor used for heat pump water heater system, changes of $CO_2$ solubility in PAG oil were investigated along the gas passages from the first stage suction to final discharge. Only slight changes in solubility took place in suction chambers for both of the first and second stages, but for compression chambers, solubility variation ranged from 0.115 to 0.136, and from 0.133 to 0.182, respectively for the first and second stages. Calculation of gas flashing in parts of leakage oil flows and of oil contained in control volumes due to solubility changes was conducted and included in gas pressure calculation. For the second stage, gas flashing amounts to around $5%\sim6%$ for most leakage flows. Cooling capacity, compressor input, and COP obtained by calculation were well compared to the experimental results. Effects of operation speed on the compressor performance was also studied: as the shaft speed increased, adiabatic efficiency decreased rapidly due to increased over-compression loss.

Performance Analysis of a $CO_2$ Two-Stage Twin Rotary Compressor ($CO_2$ 2단 트윈 로타리 압축기 성능해석)

  • Kim, Woo-Young;Ahn, Jong-Min;Kim, Hyun-Jin;Cho, Sung-Oug
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.1
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    • pp.19-27
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    • 2007
  • Analytical investigation on the performance of a two stage twin rotary compressor for $CO_2$ heat pump water heater system has been carried out. A computer simulation program was made based on analytical models for gas compression in control volumes, leakages among neighboring volumes, and dynamics of moving elements of the compressor. Calculated cooling capacity, compressor input, and COP were well compared to those of experiments over the compressor speeds tested. For the operating condition of suction pressure of 3 MPa, and discharge pressure of 9 MPa, and compressor inlet temperature of $35^{\circ}C$, the compressor efficiency was calculated to be 80.2%: volumetric, adiabatic, and mechanical efficiencies were 88.3%, 93.2%, and 92.7%, respectively. For the present compressor model, volumetric and adiabatic efficiencies of the second stage cylinder were lower by about $6{\sim}7%$ than those of the first stage mainly due to the smaller discharge port at the second stage. Parametric study on the discharge port size showed that the compressor performance could be improved by 3.5% just by increasing the discharge port diameter by 20%.

The Design and Implementation of EL/LX level3 C Standard Library for RTOS Qplus-P (EL/IX 단계 3을 적용한 실시간 운영체제 Qplus-P용 C 표준 라이브러리의 설계 및 구현)

  • Kim, Do-Hyung;Shin, Chang-Min;Park, Sung-Min
    • The KIPS Transactions:PartA
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    • v.9A no.4
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    • pp.485-490
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    • 2002
  • As the products of internet appliance, such as digital TV, internet set-top box, and internet phone, are continually produced, the market of real time operating system which controls those products is being highly increased. ETRI developed the extensible real time operating system, Qplus-P, which can be used from PDA to internet set-top box and home server. This paper describes the design and implementation of C standard library for real-time operating system Qplus-P. The Qplus-P C standard library follows EL/IX API level, which is proposed to the real-time operating system international standard by the RedHat. And, the C standard library functions, which are needed to support the Tiny-X and Kaffe, are also implemented. The implemented C standard library can reduce the size of library about 30% compare to the C library that does not follow EL/IX API level.

A Study on the Development of Pattern Design Tool for CCFL Backlight (CCFL 백라이트 패턴 설계툴 개발에 관한 연구)

  • Cho Young-Chang;Choi Byung-Jin;Yoon Jeong-Oh
    • Journal of Korea Society of Industrial Information Systems
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    • v.11 no.2
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    • pp.79-85
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    • 2006
  • As the portable information appliance is developed, the demand of flat panel display equipments and parts are steeply increased. Most of all, the applications of LCD such as LCD TV, monitor, digital camera, CNS(car navigation system) and game machine become diversified. With the result that the number of BLU production enterprise is increased and the research on the design of backlight with the superior optical properties is persistently in progress. In this study we developed the pattern design tools for CCFL(cold cathode flourescent lamp) backlight to improve the conventional pattern design environment in which the pattern is designed manually from the experience and the trial and error. For the verification of our research, we designed the light reflection surface patterns for a real model of backlight and we measured the brightness uniformity using the BM-7. From the brightness uniformity measurement, the BLU designed using the presented tool showed the tolerable performance only in the first try of pattern design rather than the fifth try of pattern design in case of the conventional pattern design.

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Experimental Investigation on the Optimal Design of Water Tank for Domestic Hot Water Supply using PEMFC Co-generation System (가정용 고분자 전해질 연료전지 열병합 발전시스템의 급탕 적용을 위한 온수 저장조의 최적 설계에 관한 실험적 연구)

  • Hwang, Yu-Jin;Ahn, Young-Chull;Cheong, Seong-Ir;Jin, Keun-Ho;Lee, Jae-Keun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.6
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    • pp.394-399
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    • 2008
  • There are many attempts to use a fuel cell system as a residential power generation system. The purpose of this study is to investigate the optimal design of a water tank for a hot water system when the fuel cell co-generation system is combined with a domestic hot water supply system. The demands of hot water supply per month per home are investigated in Busan for a year. It showed somewhat large differences between the actual demand and the designed demand of hot water, but the actual capacity of hourly averaged hot water demands is analyzed as $60{\ell}/h$ in this study based on the actual demand. The experiments are performed in the various inlet and outlet locations of nozzles, and the hot water consumption rates. The experimental results are showed that the optimal capacity of the water tank is $200{\ell}$ when the thermal efficiency, the storing capacity of hot water and the space for installation are considered.

Intelligent Home appliances Power Control using Android and Arduino (안드로이드와 아두이노를 이용한 지능형 가전제품 전력 컨트롤)

  • Park, Sung-hyun;Kim, A-Yong;Kim, Wung-Jun;Bae, Keun-Ho;Yoo, Sang-keun;Jung, Hoe-kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.854-856
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    • 2014
  • Has been released of make it possible to control the using for smart devices of a wide variety home appliances and electronics in smart appliances in accordance with the one person multi devices. In addition, is increasing rapidly for the number of the product on cleaning robot and refrigerator, air conditioning, TV, etc. these devices are using the implement up DLNA system. And at home and abroad for development and has provided with Iot and Alljoyn such systems. But currently using home appliances or electronic devices of there are a lot of the operating system non installed than the installed products. In addition, smart appliances do not use for user than buying existing electronic products a lot more. In addition, more occur for smart appliances of that do not use for the user on smart appliances rather than buying existing electronics. In this paper, Suggested and implemented for system of control such as smart devices to existed home appliance on not have an operating system, Using mobile device for want users to quantify the data to transfer from arduino board.

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Effectiveness of low-level laser therapy in facilitating maxillary expansion using bone-borne hyrax expander: A randomized clinical trial

  • Abdelwassie, Sara Hassan;Kaddah, Mohammed Amgad;El-Dakroury, Amr Emad;El-Boghdady, Dalia;Abd El-Ghafour, Mohamed;Seifeldin, Nouran Fouad
    • The korean journal of orthodontics
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    • v.52 no.6
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    • pp.399-411
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    • 2022
  • Objective: The objective of this randomized clinical trial was to study the skeletal and dental effects of low-level laser therapy (LLLT) along with a miniscrew-assisted expander (Hyrax) after six months of retention. Methods: After sequence generation, concealed allocation, and implementation, 24 female patients were randomly divided (1:1) into two-groups: bone-borne rapid palatal expansion (BBE) without LLLT (n = 12) and BBE with LLLT (n = 12). Eligibility criteria included female patients aged 10-13 years old with bilateral posterior crossbites. Intraoral and extraoral photographs, cone-beam computed tomography images, and digital study models were obtained before expansion and six months after retention. The 7 mm Hyrax appliance was anchored to four palatal mini-screws, which were activated twice daily for 15 days, then locked and kept in place as a retainer. LLLT was performed in the laser group during expansion and retention, according to the guidelines provided. Results: The records of 24 patients were analyzed. According to the post-retention measurements, both groups showed a significant increase in nasal and maxillary widths and total facial height. In the laser group, the Sella-Nasion-Point A and Point A-Nasion-Point B angles and the interpremolar apical distance were significantly increased. Conclusions: Within the limitations of this study, the results suggest that the parameters and protocol of LLLT do not clinically affect the efficiency of BBE in prepubertal and pubertal patients.

Characterization of Volatile Compounds in Low-Temperature and Long-Term Fermented Baechu Kimchi (묵은 배추김치의 휘발성 성분 특성)

  • Kim, Ji-Yun;Park, Eun-Young;Kim, Young-Suk
    • Journal of the Korean Society of Food Culture
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    • v.21 no.3
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    • pp.319-324
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    • 2006
  • Volatile compounds in low-temperature and long-term fermented Baechu kimchi were extracted by high vacuum sublimation(HVS), and then analyzed by gas chromatography/mass spectrometry(GC-MS). A total of 62 compounds, including 7 sulfur-containing compounds, 8 terpenes, 5 esters, 8 acids, 15 alcohols, 2 nitrites, 2 ketones, 11 aliphatic hydrocarbons and 4 miscellaneous compounds, were found in low-temperature and long-term fermented Baechu kimchi. Among them, acetic acid and butanoic acid were quantitatively dominant. Aroma-active compounds were also determined by gas chromatography/olfactometry(GC-O) using aroma extract dilution analysis(AEDA). A total of 16 aroma-active compounds were detected by GC-O. Butanoic acid was the most potent aroma-active compound with the highest FD factor($Log_3FD$) followed by linalool, acetic acid, 2-vinyl-4H-1,3-dithin and 3-methyl-1-butanol. The major aroma-active compounds, such as acetic acid and butanoic acid, were related to sour and rancid or notes.

A Ranking Cleaning Policy for Embedded Flash File Systems (임베디드 플래시 파일시스템을 위한 순위별 지움 정책)

  • Kim, Jeong-Ki;Park, Sung-Min;Kim, Chae-Kyu
    • The KIPS Transactions:PartA
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    • v.9A no.4
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    • pp.399-404
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    • 2002
  • Along the evolution of information and communication technologies, manufacturing embedded systems such as PDA (personal digital assistant), HPC (hand -held PC), settop box. and information appliance became realistic. And RTOS (real-time operating system) and filesystem have been played essential re]os within the embedded systems as well. For the filesystem of embedded systems, flash memory has been used extensively instead of traditional hard disk drives because of embedded system's requirements like portability, fast access time, and low power consumption. Other than these requirements, nonvolatile storage characteristic of flash memory is another reason for wide adoption in industry. However, there are some technical challenges to cope with to use the flash memory as an indispensable component of the embedded systems. These would be relatively slow cleaning time and the limited number of times to write-and-clean. In this paper, a new cleaning policy is proposed to overcome the problems mentioned above and relevant performance comparison results will be provided. Ranking cleaning policy(RCP) decides when and where to clean within the flash memory considering the cost of cleaning and the number of times of cleaning. This method will maximize not only the lifetime of flash memory but also the performance of access time and manageability. As a result of performance comparison, RCP has showed about 10 ~ 50% of performance evolution compared to traditional policies, Greedy and Cost-benefit methods, by write throughputs.

Perceptional Change of a New Product, DMB Phone

  • Kim, Ju-Young;Ko, Deok-Im
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.3
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    • pp.59-88
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    • 2008
  • Digital Convergence means integration between industry, technology, and contents, and in marketing, it usually comes with creation of new types of product and service under the base of digital technology as digitalization progress in electro-communication industries including telecommunication, home appliance, and computer industries. One can see digital convergence not only in instruments such as PC, AV appliances, cellular phone, but also in contents, network, service that are required in production, modification, distribution, re-production of information. Convergence in contents started around 1990. Convergence in network and service begins as broadcasting and telecommunication integrates and DMB(digital multimedia broadcasting), born in May, 2005 is the symbolic icon in this trend. There are some positive and negative expectations about DMB. The reason why two opposite expectations exist is that DMB does not come out from customer's need but from technology development. Therefore, customers might have hard time to interpret the real meaning of DMB. Time is quite critical to a high tech product, like DMB because another product with same function from different technology can replace the existing product within short period of time. If DMB does not positioning well to customer's mind quickly, another products like Wibro, IPTV, or HSPDA could replace it before it even spreads out. Therefore, positioning strategy is critical for success of DMB product. To make correct positioning strategy, one needs to understand how consumer interprets DMB and how consumer's interpretation can be changed via communication strategy. In this study, we try to investigate how consumer perceives a new product, like DMB and how AD strategy change consumer's perception. More specifically, the paper segment consumers into sub-groups based on their DMB perceptions and compare their characteristics in order to understand how they perceive DMB. And, expose them different printed ADs that have messages guiding consumer think DMB in specific ways, either cellular phone or personal TV. Research Question 1: Segment consumers according to perceptions about DMB and compare characteristics of segmentations. Research Question 2: Compare perceptions about DMB after AD that induces categorization of DMB in direction for each segment. If one understand and predict a direction in which consumer perceive a new product, firm can select target customers easily. We segment consumers according to their perception and analyze characteristics in order to find some variables that can influence perceptions, like prior experience, usage, or habit. And then, marketing people can use this variables to identify target customers and predict their perceptions. If one knows how customer's perception is changed via AD message, communication strategy could be constructed properly. Specially, information from segmented customers helps to develop efficient AD strategy for segment who has prior perception. Research framework consists of two measurements and one treatment, O1 X O2. First observation is for collecting information about consumer's perception and their characteristics. Based on first observation, the paper segment consumers into two groups, one group perceives DMB similar to Cellular phone and the other group perceives DMB similar to TV. And compare characteristics of two segments in order to find reason why they perceive DMB differently. Next, we expose two kinds of AD to subjects. One AD describes DMB as Cellular phone and the other Ad describes DMB as personal TV. When two ADs are exposed to subjects, consumers don't know their prior perception of DMB, in other words, which subject belongs 'similar-to-Cellular phone' segment or 'similar-to-TV' segment? However, we analyze the AD's effect differently for each segment. In research design, final observation is for investigating AD effect. Perception before AD is compared with perception after AD. Comparisons are made for each segment and for each AD. For the segment who perceives DMB similar to TV, AD that describes DMB as cellular phone could change the prior perception. And AD that describes DMB as personal TV, could enforce the prior perception. For data collection, subjects are selected from undergraduate students because they have basic knowledge about most digital equipments and have open attitude about a new product and media. Total number of subjects is 240. In order to measure perception about DMB, we use indirect measurement, comparison with other similar digital products. To select similar digital products, we pre-survey students and then finally select PDA, Car-TV, Cellular Phone, MP3 player, TV, and PSP. Quasi experiment is done at several classes under instructor's allowance. After brief introduction, prior knowledge, awareness, and usage about DMB as well as other digital instruments is asked and their similarities and perceived characteristics are measured. And then, two kinds of manipulated color-printed AD are distributed and similarities and perceived characteristics for DMB are re-measured. Finally purchase intension, AD attitude, manipulation check, and demographic variables are asked. Subjects are given small gift for participation. Stimuli are color-printed advertising. Their actual size is A4 and made after several pre-test from AD professionals and students. As results, consumers are segmented into two subgroups based on their perceptions of DMB. Similarity measure between DMB and cellular phone and similarity measure between DMB and TV are used to classify consumers. If subject whose first measure is less than the second measure, she is classified into segment A and segment A is characterized as they perceive DMB like TV. Otherwise, they are classified as segment B, who perceives DMB like cellular phone. Discriminant analysis on these groups with their characteristics of usage and attitude shows that Segment A knows much about DMB and uses a lot of digital instrument. Segment B, who thinks DMB as cellular phone doesn't know well about DMB and not familiar with other digital instruments. So, consumers with higher knowledge perceive DMB similar to TV because launching DMB advertising lead consumer think DMB as TV. Consumers with less interest on digital products don't know well about DMB AD and then think DMB as cellular phone. In order to investigate perceptions of DMB as well as other digital instruments, we apply Proxscal analysis, Multidimensional Scaling technique at SPSS statistical package. At first step, subjects are presented 21 pairs of 7 digital instruments and evaluate similarity judgments on 7 point scale. And for each segment, their similarity judgments are averaged and similarity matrix is made. Secondly, Proxscal analysis of segment A and B are done. At third stage, get similarity judgment between DMB and other digital instruments after AD exposure. Lastly, similarity judgments of group A-1, A-2, B-1, and B-2 are named as 'after DMB' and put them into matrix made at the first stage. Then apply Proxscal analysis on these matrixes and check the positional difference of DMB and after DMB. The results show that map of segment A, who perceives DMB similar as TV, shows that DMB position closer to TV than to Cellular phone as expected. Map of segment B, who perceive DMB similar as cellular phone shows that DMB position closer to Cellular phone than to TV as expected. Stress value and R-square is acceptable. And, change results after stimuli, manipulated Advertising show that AD makes DMB perception bent toward Cellular phone when Cellular phone-like AD is exposed, and that DMB positioning move towards Car-TV which is more personalized one when TV-like AD is exposed. It is true for both segment, A and B, consistently. Furthermore, the paper apply correspondence analysis to the same data and find almost the same results. The paper answers two main research questions. The first one is that perception about a new product is made mainly from prior experience. And the second one is that AD is effective in changing and enforcing perception. In addition to above, we extend perception change to purchase intention. Purchase intention is high when AD enforces original perception. AD that shows DMB like TV makes worst intention. This paper has limitations and issues to be pursed in near future. Methodologically, current methodology can't provide statistical test on the perceptual change, since classical MDS models, like Proxscal and correspondence analysis are not probability models. So, a new probability MDS model for testing hypothesis about configuration needs to be developed. Next, advertising message needs to be developed more rigorously from theoretical and managerial perspective. Also experimental procedure could be improved for more realistic data collection. For example, web-based experiment and real product stimuli and multimedia presentation could be employed. Or, one can display products together in simulated shop. In addition, demand and social desirability threats of internal validity could influence on the results. In order to handle the threats, results of the model-intended advertising and other "pseudo" advertising could be compared. Furthermore, one can try various level of innovativeness in order to check whether it make any different results (cf. Moon 2006). In addition, if one can create hypothetical product that is really innovative and new for research, it helps to make a vacant impression status and then to study how to form impression in more rigorous way.

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