• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.558-567
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• 1999

X-ray laminography and DT(digital tomosynthesis) that can form a cross-sectional image of 3-D objects promis to be good solutions for inspecting interior defects of industrial products. DT is a kind of laminography technique and the difference is in the fact that it synthesizes the several projected images by use of the digitized memory and computation. The quality of images acquired from the DT system varies according to image synthesizing methods, the number of images used in image synthesizing, and X-ray projection angles. In this paper, a new image synthesizing method named 'log-root method' is proposed to get clear and accurate cross-sectional images, which can reduce both artifact and blurring generated by materials out of focal plane. To evaluate the quality of cross-sectional images, two evaluating criteria : (1) shape accuracy and (2) clearness of the cross-sectional images are defined. Based on these criteria, a series of simulations are performed, and the results show the superiority of the new synthesizing method over the existing ones such as averaging and minimum methods.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.9-19
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• 2010

Every car manufacturer desires to reduce the new car development time spent in improving the safety, NVH, lightweight, reliability and environment friendly features of the car. Other considerations such as planning, exterior and interior styling, packaging, color, and material selection increase the complexity of the car design process. This paper proposes a personal DDP (Digital Design Process) to utilize the engineering analysis and design/styling software for car design. DDP can be efficiently used by a team of car research center or a studio with small number of engineers, helping ordinary engineers becoming ambidextrous in design as well as engineering applications. The concept model starts from idea sketch, rendering, and 3D surface model with CAS (Computer Aided Styling) to the final safety estimation by using proposed DDP based on engineering technology (CAD, CAE). The concept model proposed a hydrogen fuel cell sports coupe which could be available within next 10 years. The proposed DDP can not only reduce the new car development time but also be adapted into designing of varied products such as aircraft, yacht, electrical equipment and sports gear.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.202-209
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• 2021

Natural dyes are more expensive than synthetic dyes and the dyeing process, which is mainly immersion of dye, is complicated. For this reason, relatively small-scale production methods were predominant. However, awareness and interest in environmental sustainability is rising globally, and the use of synthetic dyes causes various environmental problems such as wastewater and CO₂ emission, so the consumption of natural dyes is increasing. In addition, interest in digital textile printing, an eco-friendly dyeing method that can produce products of various designs and uses less water, is growing. In this study, natural indigo dye (Indigofera tinctoria) was used as a raw material for Digital Textile Printing ink, and ¹⁴C (Biocarbon) present in it was measured to confirm whether it was derived from natural ingredients. The performance was confirmed by testing the pH, viscosity, electrical conductivity, surface tension, and particle size analysis of natural indigo ink. In addition, the performance of natural indigo DTP ink and printing fabric was evaluated by inspecting the change in color fastness and corresponding index substances before and after digital printing with natural indigo DTP ink on textiles. Through this, the possibility of commercialization of DTP ink and printing fabric using natural indigo was confirmed.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.836-845
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• 2017

Gravimetric method is usually used to evaluate air-dry density, which is governing physical or mechanical properties of wood. Although it had high evaluation accuracy, the method is time consuming process. Thus, this study was conducted to estimate air-dry density of wood with high accuracy by using polychromatic X-ray and digital detector as alternative of gravimetric method. To quantify polychromatic X-ray projection for evaluating air-dry density, Lambert-Beer's law with the integral value of probability function was used. The integral value was used as weighting factor in the law, and it was determined by conducting simple test at various penetration depths and tube voltage. Mass attenuation coefficient (MAC) of wood also calculated by investigating polychromatic X-ray projection according to species, penetration depth and tube voltage. The species had not an effect on change of MAC. Finally, an air-dry density of wood was estimated by applying the integral value, MAC and Lambert-Beer's law to polychromatic X-ray projection. As an example, the relation of the integral value (${\alpha}$) according to penetration depth (t, cm) at tube voltage of 35 kV was ${\alpha}=-0.00091t{\times}0.0184$ while the regression of the MAC (${\mu}$, $cm^2/g$) was ${\mu}=0.5414{\exp}(-0.0734t)$. When calculation of root mean squared error (RMSE) was performed to check the estimation accuracy, RMSE at 35, 45 and 55 kV was 0.010, 0.013 and $0.009g/cm^3$, respectively. However, partial RMSE in relation to air-dry density was varied according to tube voltage. The partial RMSE below air-dry density of $0.41g/cm^3$ was $0.008g/cm^3$ when tube voltage of 35 kV was used. Meanwhile, the partial RMSE above air-dry density of $0.41g/cm^3$ decreased as tube voltage increased. It was conclude that the accuracy of estimation with polychromatic X-ray and digital detector was quite high if the integral value and MAC of wood were determined precisely or a condition of examination was chosen properly. It was seemed that the estimation of air-dry density by using polychromatic X-ray system can supplant the gravimetric method.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.888-894
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• 2009

Recently, touch screen systems with direct touch interfaces are prevailing in digital products such as MP3's, DMB's, PDA's and navigators, which give rise to new interface issues related to speed, feedback and accuracy, and consider additional considerations for solving those issues in evaluation processes. Although paper prototyping method, the one of applicable methods, is efficient ways to evaluate the touch interface, it still requires a certain amount of adaptations for touch interfaces. This study aims to identify emerged issues regarding to paper-prototyping method for the evaluation of touch interface, to come up with alternatives for applying the method. The study started with analyzing the touch interface in digital products, and suggests the 'Touch Wheel' interface based on mainly used interface. 'Touch Wheel' interface allows the user searching for her/his favorite songs by rolling 'wheel-like' menu list. The Userbility test was conducted by 24 MP3 users with 4 times, and based on such conditions as materials, making methods and evaluating process of paper prototyping for evaluating the touch interface, effective alternatives were considered in each evaluation steps. As a result, paper prototypes for evaluating the touch interface should give active operations to subjects by offering direct experience, so as to provide subjects with proper feedbacks and for designers to collect effective alternatives for expected problems in initial interface design process.

• Archives of design research
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• v.16 no.3
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• pp.273-280
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• 2003

Priming Effect, as a part of "Contextual Effect" is the phenomenon that pre-searched product information influences consecutive product evaluation. "Priming Effect" is different from other types of "Contextual Effects" in that pre-searched information doesn't have an direct effect on product evaluation, but an indirect effect which means that pre-searched information influences interpretation of consecutive product evaluation. On the previous theoretical background, this study investigated that how visual images can influence consumer preference and product choice, introducing concept of priming effects into the design of on-line shopping malls. This experiment adopted the digital cameras as the experimental stimulus target products and designed the individual web pages by priming the attributes of price and size. In result of analysis, the difference of product preference by priming attributes was proved to be statistically significant. In this reason, suggesting the background of commercial web page can be the significant factor in choosing products, the priming effects introduced into the design can be positively employed in online advertising.mployed in online advertising.

• Journal of Digital Contents Society
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• v.15 no.5
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• pp.595-602
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• 2014

Cloud computing is already well known paradigm that a support computing resource flexible and scalable to users as the want in distributed computing environment. Actually, cloud computing can be implemented and provided by virtualization technology. Also, various products are released or under development. In this paper, we built the teaching practice system using cloud computing and evaluated practical environment which constructed over a virtual machine. Virtualization-based cloud computing provides optimized computing resources, as well as easy to manage practical resource and result. Therefore, we can save the time for configuration of practice environment. In the view of faculty, they can easily handle the practice result. Also, those practice condition reuse comfortably and apply to various configuration simply. And then we can increase capabilities and availabilities of limited resources. Additionally, we measure the performance requirements for educational applications through evaluation of virtual-based teaching practical system in advance.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.251-259
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• 2017

Recently, the smart healthcare industry that grafted the Internet of Things (IoT) onto the healthcare and medical services is being highlighted. Smart healthcare refers to the healthcare and medical services offered on the basis of information communication technologies including application, wearable devices and platforms, etc. The number of next generation smart healthcare devices are increasing in the smart healthcare industry through the combination of information technology (IT) and Bio Technology (BT), which are the most active areas among the 6T, which are the areas of the next generation industry. With the emergence of a diverse range of smart healthcare systems or devices, whether the smart healthcare system can be linked with other systems organically and the security and quality of the system have become important elements of evaluation. In this Study, the characteristics and service types of smart healthcare systems were examined, and the trends in the technology and industry of the smart healthcare system were analyzed. Moreover, this Study aims to develop the evaluation method for security and standards for quality evaluation by deducing the factors for the evaluation of smart healthcare system on the basis of the results of aforementioned examination. It is anticipated that this can induce improvement of quality and development of highly reliable products of a smart healthcare system, and will become the core technology to substitute the technology protection barrier.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.97-117
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• 2020

Product evaluation criteria is an indicator describing attributes or values of products, which enable users or manufacturers measure and understand the products. When companies analyze their products or compare them with competitors, appropriate criteria must be selected for objective evaluation. The criteria should show the features of products that consumers considered when they purchased, used and evaluated the products. However, current evaluation criteria do not reflect different consumers' opinion from product to product. Previous studies tried to used online reviews from e-commerce sites that reflect consumer opinions to extract the features and topics of products and use them as evaluation criteria. However, there is still a limit that they produce irrelevant criteria to products due to extracted or improper words are not refined. To overcome this limitation, this research suggests LDA-k-NN model which extracts possible criteria words from online reviews by using LDA and refines them with k-nearest neighbor. Proposed approach starts with preparation phase, which is constructed with 6 steps. At first, it collects review data from e-commerce websites. Most e-commerce websites classify their selling items by high-level, middle-level, and low-level categories. Review data for preparation phase are gathered from each middle-level category and collapsed later, which is to present single high-level category. Next, nouns, adjectives, adverbs, and verbs are extracted from reviews by getting part of speech information using morpheme analysis module. After preprocessing, words per each topic from review are shown with LDA and only nouns in topic words are chosen as potential words for criteria. Then, words are tagged based on possibility of criteria for each middle-level category. Next, every tagged word is vectorized by pre-trained word embedding model. Finally, k-nearest neighbor case-based approach is used to classify each word with tags. After setting up preparation phase, criteria extraction phase is conducted with low-level categories. This phase starts with crawling reviews in the corresponding low-level category. Same preprocessing as preparation phase is conducted using morpheme analysis module and LDA. Possible criteria words are extracted by getting nouns from the data and vectorized by pre-trained word embedding model. Finally, evaluation criteria are extracted by refining possible criteria words using k-nearest neighbor approach and reference proportion of each word in the words set. To evaluate the performance of the proposed model, an experiment was conducted with review on '11st', one of the biggest e-commerce companies in Korea. Review data were from 'Electronics/Digital' section, one of high-level categories in 11st. For performance evaluation of suggested model, three other models were used for comparing with the suggested model; actual criteria of 11st, a model that extracts nouns by morpheme analysis module and refines them according to word frequency, and a model that extracts nouns from LDA topics and refines them by word frequency. The performance evaluation was set to predict evaluation criteria of 10 low-level categories with the suggested model and 3 models above. Criteria words extracted from each model were combined into a single words set and it was used for survey questionnaires. In the survey, respondents chose every item they consider as appropriate criteria for each category. Each model got its score when chosen words were extracted from that model. The suggested model had higher scores than other models in 8 out of 10 low-level categories. By conducting paired t-tests on scores of each model, we confirmed that the suggested model shows better performance in 26 tests out of 30. In addition, the suggested model was the best model in terms of accuracy. This research proposes evaluation criteria extracting method that combines topic extraction using LDA and refinement with k-nearest neighbor approach. This method overcomes the limits of previous dictionary-based models and frequency-based refinement models. This study can contribute to improve review analysis for deriving business insights in e-commerce market.

• Archives of design research
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• v.13 no.3
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• pp.123-134
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• 2000

Electronic commerce in digital environment is greatly different from the commerce in physical environment in the past (reality environment) in terms of marketing, distribution structure and, above an, comsumers'purchase pattern. The Old purchase pattern is that a consumer buys a product after s/he touches, tests, and feels it physically, while the purchase pattern in electronic commerce enables the comsumer to make a decision about whether to buy it or not through the information gleaned from the computer monitor screen. A number of products which appears in the market now are designed to use the reality environment setup without consideration of the digital environment, of which the intention is to appeal to consumers with a series of design process. However, taking under consideration the present situation in which lots of electronic commerce are made in the cyber space or digital environment, we are required to forward the product design which can gains the positive attraction for consumers in this environment. Factor analysis is made in order to understand how the subjects perceive the image of the design of the product both in reality situation and in digital environment. The result shows the first factor has different images in those environments. In the background of this conclusion rests the fact that the difference of the transfer of formative factors to consumers is made in the images which show themselves in those different environments.