• The Journal of the Korea Contents Association
• /
• v.17 no.1
• /
• pp.550-566
• /
• 2017

Recent advances in wearable devices and quantified-self movement increase the number of personal informatics application that may cause an concern to health industry and user. In this light, the goal of this study is to identify more effective ways of design and evaluation of personal informatics application for self-tracking and delivering health information to users. For this goal, this study conducted areal-world study that processes such that user can assess, be aware of, and self-reflect on their data and behavior activity. In doing so, this study aims to determine the psychological effects of forms of health feedback (comparative vs. non-comparative) and presentation modes (text vs. image) on users' tendencies toward health conservation. Results from a between-subjects experiment revealed that health information in a comparative and textual format was more effective in encouraging health conservation in participants than identical information presented in a non-comparative and image format. In addition, participants' level of health consciousness emerged as a significant predictor. Through this analysis of quantitative data and inferences, this study make a number of contributions to the user affordance research and its methodology of health informatics study and designing personal informatics application that support user's behavior change in various contexts.

• Journal of The Korean Association For Science Education
• /
• v.24 no.3
• /
• pp.556-564
• /
• 2004

Two biology modules were developed previously for the purpose of improving creativity and scientific thinking of secondary school students. A hypothetical-deductive experimental procedure was reflected in the module when students themselves can perform a series of activities of making hypothesis and designing an experiment to solve the questions. They followed a series of scientific processes to determine some characteristics regarding plant pigments and the transport process of materials in living organisms. Four classes of 9th graders in'S' Science High School were divided into the experimental and the control group. The same contents of the modules were taught to the control group by the traditional experimental way. The students' creativity, scientific thinking, scientific inquiry skill and knowledge achievement were examined before and after the interventions. As results, the experimental groups showed more significant improvement on the areas of the students' creativity, scientific thinking, scientific inquiry skill and achievement than the control groups. Results indicated that the specially designed modules in terms of hypothetical-deductive experimental procedure were effective to improve science high school students' creativity and scientific thinking abilities.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.6
• /
• pp.780-787
• /
• 2005

Many researches and validations for the complexity metrics of the object-oriented systems have been studied. Most of them are aimed for the measurement of the partial aspects of the systems, for example, the coupling between objects, the complexity of inheritance structures, the cohesion of methods, and so on. But the software practitioners want to measure the complexity of overall system, not partial. We studied the complexity of the overall structures of object-oriented systems by analyzing the class diagram of UML. The class diagram is composed of classes and their relations. There are three kinds of relations, association, generalization, and aggregation, which are making the structure of object-oriented systems to be difficult to understand. We proposed a heuristic metric to measure the complexity of object-oriented systems by putting together the three kinds of the relations. Tn analyze the complexity of the structure of a object-oriented system for the maintainability of the system, we measured the degree of understandability of it, the reverse engineering time to draw a class diagram from the source codes, and the number of errors in the diagram. The results of this experiment shows that our proposed metric has a considerable relationship with the complexity of object-oriented systems. The metric will be helpful to the software developers for their designing tasks by evaluating the complexity of the structures of object-oriented systems and redesigning tasks , of them for the future maintainability.

• 한국HCI학회:학술대회논문집
• /
• 2008.02b
• /
• pp.451-455
• /
• 2008

Emotional design gets more and more important. However, the systematical approaches to integration of user experience elements in product design have been rarely tried. This study consists of three parts. We extracted affective words fitting to design direction based on trend analysis. Then, user experience elements were matched with affective words. Finally, a prototype system was made to guide designing affective factors in electronic products. In the present study, user experience elements were defined as color, material & finishing, and sound. Through various documents analysis and trend analysis, trend analysis experts and user experience designers extracted 31 affective keywords which could fully reflect current trend. After paired-comparison of selected keywords, 2 sensibility dimensions were obtained by multidimensional scaling. Trend affective keywords could be explained by 2 dimensions of human-centered' vs. 'techno-centered' and 'warm vs. cool'. Next, user experience elements stimuli were matched with each keyword by user direct positioning on the 2 dimensions affective map. Based on the result of the experiment, the prototype system was developed for the product designers. The results of the current study could guide designers to design emotionally satisfactory products.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.13 no.2
• /
• pp.67-73
• /
• 2007

A respiration rate analysed by enzyme kinetics-based respiration model and gas permeability data of LDPE film were applied to design the optical modified atmosphere (MA) packaging condition of persimmon (Diospyros kaki cv. Fuyu) fruits. The fruit quality rapidly decreases due to physiology disorder such as softening and peel blackening. $O_2$ permeance ($Q_{O2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) and $CO_2$ performance ($Q_{CO2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) of low density polyethylene (LDPE) film samples were measured at $0^{\circ}C$ and described as function of thickness (L in ${\mu}m$) as $Q_{O2}=(2540{\times}1/L)-16$, and $Q_{CO2}=(13742{\times}1/L)-70$, respectively. MA package containing single persimmon fruit of 225g was designed and tested experimentally at $0^{\circ}C$ by using LDPE films. Package atmospheres predicted from the relationship of $O_2$, $CO_2$ and $N_2$ balances on the packages was in good agreement with those obtained experimentally. Physiology disorder occurrence was the lowest at 52 ${\mu}m$ package that attained optimum gas condition ($O_2$ 2.8% and $CO_2$ 5.4%). The computer simulation was found to be effective to help to design the optimum MA packaging condition of individual persimmon fruit.

• Tunnel and Underground Space
• /
• v.21 no.3
• /
• pp.151-163
• /
• 2011

The LCM test is one of the most powerful and reliable methods for designing the disc cutter and for predicting the TBM (Tunnel Boring Machine) performance. It has an advantage to predict the actual load on disc cutter from the laboratory test on the real-size large rock samples, however, it also has a disadvantage to transport and/or prepare the large rock samples and to need an extra cost for experiment. Moreover it is not easy to execute the test for jointed rock mass, and sometimes the design model estimated from the test can not be applied to the real design of disc cutter. In order to break this critical point, lots of numerical studies have been performed. PFC2D can simulate crack propagation and rock fragmentation effectively, because it is useful in particle flow analysis. Consequently, in this study, the PFC2D has been adopted for numerical analysis on cutting power of disc cutter according to the different angle of joint, the different direction of joint, and the different space of joint with jointed rock mass models. From the numerical analyses, it was concluded that the bigger cutting power of disc cutter was needed for reverse cutting direction to joint rather than for forward direction, and the cutting power of disc cutter was increased with decreasing the dip angle of joint and decreasing the space of joints in reverse cutting direction. The more precise numerical model for disc cutter can be developed from comparison between the numerical results and LCM test results, and the resonable guideline is expected for prediction of TBM performance and disc cutter.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.1
• /
• pp.28-37
• /
• 2010

In this paper, the IC (Integrated Circuit) for multi-channel asynchronous communication was designed by using FPGA and VHDL language. The existing chips for asynchronous communication that has been used commercially are composed of one to two channels. Therefore, when communication system with two channels or more is made, the cost becomes high and it becomes complicated for communication system to be realized and also has very little buffer, load that is placed into Microprocessor increases heavily in case of high speed communication or transmission of high-capacity data. The designed IC was improved the function and performance of communication system and reduced costs by designing 8 asynchronous communication channels with only one IC, and it has the size of transmitter/receiver buffer with 256 bytes respectively and consequently high speed communication became possible. To detect errors between communications, it was designed with digital filter and check-sum logic and channel MUX logic so that the malfunction can be prevented and errors can be detected more easily and input/output port regarding each communication channel can be used flexibly and consequently the reliability of system was improved. It was composed and simulated logic of VHDL described by using Cyclone II Series EP2C35F672C8 and QuartusII V8.1 of ALTERA company. In order to show the performance of designed IC, the test was conducted successfully in QuartusII simulation and experiment and the excellency was compared with TL16C550A of TI (Texas Instrument) company and ATmegal28 general-purpose micro controller of ATMEL company that are used widely as chips for asynchronous communication.

• Journal of the HCI Society of Korea
• /
• v.1 no.1
• /
• pp.21-28
• /
• 2006

Most of the commercialized wearable text input devices are wrist-worn keyboards that have adopted the minimization method of reducing keys. Generally, a drastic key reduction in order to achieve sufficient wearability increases KSPC(Keystrokes per Character), decreases text entry performance, and requires additional effort to learn a new typing method. We are faced with wearability-usability tradeoff problems in designing a good wearable keyboard. To address this problem, we introduced a new keyboard minimization method of reducing key pitch. From a series of empirical studies, we found the potential of a new method which has a keyboard with a 7mm key pitch, good wearability and social acceptance in terms of physical form factors, and allows users to type 15.0WPM in 3 session trials. However, participants point out that a lack of passive haptic feedback in keying action and visual feedback on users' input deteriorate the text entry performance. We have developed the One-key Keyboard that addresses this problem. The traditional desktop keyboard has one key per character, but the One-key Keyboard has only one key ($70mm{\times}35mm$) on which a 10*5 QWERTY key array is printed. The One-key Keyboard detects the position of the fingertip at the time of the keying event and figures out the character entered. We conducted a text entry performance test comprised of 5 sessions. The participants typed 18.9WPM with a 6.7% error rate over all sessions and achieved up to 24.5WPM. From the experiment's results, the One-key Keyboard was evaluated as a potential text input device for wearable computing, balancing wearability, social acceptance, input speed, and learnability.

• Journal of Radiation Protection and Research
• /
• v.32 no.3
• /
• pp.117-122
• /
• 2007

The hydrodynamic behaviors of the clarifier with an interior baffle in a wastewater treatment plant was investigated by using a radiotracer $^{99m}Tc$(30 40 mCi) to verify the results of CFD(computational fluid dynamics) modelling in the previous study. The clarifier model was manufactured with consideration to the hydraulic similarity(1/21) of a real plant($L{\times}W{\times}H:2.6{\times}0.4{\times}0.2m$). By installation of an interior baffle to the clarifier, the strong density current at the bottom of the clarifier decreased substantially and increased the area of sludge settling zone, which were visualized successfully from the radiotracer experiment. Also the portion of short circuit stream changed from 48 % to 32 % and the mean residence time of sludge decreased from 940 sec to 810 sec, which corresponds to the results of CFD modelling. As a result, it is anticipated that radiotracer technology can be used as an important tool for designing new wastewater treatment plants and verifying their performances after structural modifications.

• Journal of The Korean Association For Science Education
• /
• v.24 no.6
• /
• pp.1245-1255
• /
• 2004

The purpose of this study is to develop a valid and reliable evaluating instrument for elementary school fifth and sixth graders. The instrument is developed through R&D procedure, which includes two checks of science specialist and two field trials of the instrument. Evaluating items are content-free for each science inquiry skill. Each science inquiry element is based on SAPA and the 7th curriculum. This study has selected 10 science inquiry skills(observing, classifying, measuring, predicting, inferring, recognizing of a problem, controlling variables, interpreting data, drawing a conclusion, designing an experiment), formulated a clear definition of the elements of science inquiry skills, and established the objectives of evaluation. The content areas are divided into three categories, material and energy, life and environment, and the earth and circulation. Each category contains 10 items. So the instrument consists of 30 items. The content validity of items, objectivity of the scoring keys, and clarity of the items has been checked twice by specialists in science education. At the same time, two field trials were performed to produce the reliability of the instruments, discrimination index, and item difficulty index. The instrument has the content validity is 91.6%, reliability 0.79, objectivity 93.3%, discrimination index 0.30, and item difficulty index 66.1%.