• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.21-28
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• 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 the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.759-769
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• 2015

Diode rectifiers are very popular in industry. However, they include large low-order harmonics in the input current and do not satisfy harmonic current content restrictions. To reduce the harmonics to the power system, several methods have been introduced. It is heavy and expensive solution to use passive filters as the solution for high power application. Another solution for the harmonic filter is utilization of active filter, but it is too expensive solution. Diode rectifiers with configurations using switching device have been introduced, but they are very complicated. The combined 12-pulse diode rectifier with the square auxiliary voltage supply has been introduced. It has the advantages that auxiliary circuit is simple and inexpensive compared to other strategies. The advanced auxiliary voltage supply in this thesis is presented as a new solution. When the square auxiliary voltage supply applied, the improvement of THD is 6~60[%] in whole load range. But when the advanced auxiliary voltage supply applied, it shows stable and excellent reduction effect of THD as 57~71[%]. Especially, for the case with 10[%] load factor, reduction effect of THD has little effect as 6[%] in the case of inserting a square auxiliary voltage supply. But when the proposed new solution applied, reduction effect has excellent effect as 71[%]. Theoretical analysis of the combined 12-pulse diode rectifier with the advanced auxiliary voltage supply is presented and control methods of the auxiliary supply is proposed. The reduction in the input current harmonics is verified by simulation using software PSIM.

• Informatization Policy
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• v.27 no.3
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• pp.56-81
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• 2020

The purpose of this research is to empirically examine the effects of motivation and skill for digital devices and the Internet on the use of online services in the severely disabled people. In addition to the general effect of digital divide, particularly for the case of severely disabled people, the effects of physical and mental inconvenience of individuals were taken into account and the moderating effect was confirmed by classifying the groups that need help with online activities and those that do not. The 2018 Digital Divide Survey data of the National Information Society Agency was used for the study. As a research method, path analysis and multi-group analysis using a sequence access model to Internet use were performed. As a result, it was confirmed that even in the case of the disabled, the motivational factor affects the skill for digital device operation and Internet use, and this access skill sequentially affects the use of online services. In particular, it was found that the effect of strategic and technical skill for internet use is the most important for the use of online services for the disabled rather than the motivation or a simple operational skill for digital devices. In addition, it was found that even in the disabled group, those requiring help in using the Internet was more passive in using the online service than the rest in the group. The results of this study suggest the need for stronger capacity for physical access as well as support in building strategic and technical skills that enhance responsibilities and protect from risks in using the Internet among the people with disabilities.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.2 s.42
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• pp.37-46
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• 2005

To date, many viable smart base isolation systems have been proposed and investigated. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively, of the smart base isolation system. A fuzzy logic controller (FLC) is used to modulate the MR damper because the FLC has an inherent robustness and ability to handle non linearities and uncertainties. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. This method is efficient in improving local portions of chromosomes. Neuro fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find optimal fuzzy rules and the GA optimized FLC outperforms not only a passive control strategy but also a human designed FLC and a conventional semi active control algorithm.

• Journal of The Korean Association For Science Education
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• v.37 no.5
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• pp.787-797
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• 2017

In this study, we investigated the features of using smart devices in socioscientific issues (SSI) debate classes. Twenty-seven high school students in Gyeonggi-do participated in this study. The processes of the SSI debate classes with smart devices were classified into five stages: data searching, data sharing, summary and organization of data, debate in the classroom, and online debate. Then some features at each stage were identified. It was found that they collected self-directed and in-depth data while reflecting their knowledge and experience, and selected data which were easy to understand at the stage of data searching. The specificity and validity of the evidences gathered and the clarity of the sources were improved at the stage of data sharing, although they shared more data offline than online. They organized their data by using paper rather than smart devices at the stage of summary and organization of data. Most of them failed to use the summary in debate. They argued and refuted based on concrete grounds at the stage of debate in the classroom, which raised students' interest in debate and led students to participate actively. At the stage of online debate, they were able to rearrange and review the arguments of both sides, and the participation of the students who were passive in classroom debate was enhanced. Based on these results, we suggest some effective teaching methods for SSI debate classes using smart devices.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.6
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• pp.902-910
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• 2008

A view of the Orientalism that sees the Orient as the inferior Other, characterized by the heterogenic, eccentric, backward, and passive features, has been internalized in the unconsciousness of Westerners. 'Orientalism' which is the cultural device and the system of discourse to put Asia in the fixed frame of dominance was the West European centered term, designating Southwest Asia including South Europe and North Africa as Orient, and contained the idea that non-Western society could progress only with the acceptance of Western civilization. Accordingly, it is need to use this term deliberately. In addition, even though the Asian Look of the West, borrowing the images and costume styles of Asia has lost the original mentality of Asia, it was not initiated from the perception that sees Asia as the inferior Other. Since the Asian Ethnic Look is the Western costume, borrowing the image of Orient and style by being fascinated by Oriental Aesthetics, the attributes of it are different from those of Orientalism. Therefore, it is not appropriate to designate the Asian Ethnic Look as 'Orientalism Fashion' or 'Oriental Look' except for some eccentric manipulation of Asia costume and image. Instead, it is desirable to exchange the term 'Asian Look', 'Asian Fashion', and 'Asian Ethnic Look' upon occasions or the name of individual nation or region can be referred to as preferred alternatives. Today, Asia including Korea is taking the initiative in the World Fashion as one of central axes of World Fashion Industry, and cannot be interpreted from the perspective of West Centrism. Now, it's time to dissolve the dichotomous prejudice of the West centrism on Asia's own strength.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.3
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• pp.181-192
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• 2022

Active vibration control system(AVCS) for helicopter enables to control the vibration generated from the main rotor and has the superb vibration reduction performance with low weight compared passive vibration reduction device. In this paper, FxLMS algorithm-based vibration control software of the light civil helicopter tansmits the control command calculated using the signals of the tachometer and accelerometers to the circular force generator(CFG) is developed and verified. According to the RTCA DO-178C/DO-331, the vibration control software is developed through the model based design technique, and real-time operation performance is evaluated in PILS(processor in-the loop simulation) and HILS(hardware in-the loop simulation) environments. In particular, the reliability of the software is improved through the LDRA-based verification coverage in the PIL environments. In order to AVCS to light civil helicopter(LCH), the dynamic response characteristic model is obtained through the ground/flight tests. AVCS configuration which exhibits the optimal performance is determined using system optimization analysis and flight test and obtain STC certification.

• Design Convergence Study
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• v.16 no.5
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• pp.1-20
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• 2017

Cardio-cerebrovascular disease is one of the chronic diseases that often attack people in Korea, and in fact, it ranks second in terms of death rate. This disease can be prevented by improving lifestyle, usual health care is important. But, in Korea most of the prevention or management programs adopt passive methods like using guide books or giving lectures, so it is not very effective in preventing the disease. Presently, the smart health care market is being developed in Korea and overseas. As an example, quantified self is being spread through wearable devices which are intended to measure each individual's health conditions and quantify body data into numbers for bettering habits. Accordingly, this author will explore and discuss wearable health care devices so as to prevent and manage cardio-cerebrovascular disease in a more active way. First, this study has classified wearable health care devices presently commercialized or related with cardio-cerebrovascular disease into wrist, clothes, or attaching types by the way of their attachment and analyzed them. After that, summing that up, this author performed cross-tabulations with other ways of preventing cardio-cerebrovascular disease. This will contribute to improving one's health care behavior about disease more actively and also work as an active interdisciplinary mechanism in research dealing with how to prevent disease afterwards.

• Korean Security Journal
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• no.19
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• pp.225-244
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• 2009

Electronic security system is composed mainly of electronic-information-communication device, so system technology, configuration and management of the electronic security system could be affected by the change of information-communication environment. This study is to propose the future prospect on the development of technique for electronic security system through the analysis of the trend and the actual condition on the development of technique. This study is based on literature study and interview with user and provider of electronic security system, also survey was carried out by system provider and members of security integration company to come up with more practical result. Hybrid DVR technology that has multi-function such as motion detection, target tracking and image identification is expected to be developed. And 'Embedded IP camera' technology that internet server and image identification software are built in. Those technologies could change the configuration and management of CCTV system. Fingerprint identification technology and face identification technology are continually developed to get more reliability, but continual development of surveillance and three-dimension identification technology for more efficient face identification system is needed. As radio identification and tracking function of RFID is appreciated as very useful for access control system, hardware and software of RFID technology is expected to be developed, but government's support for market revitalization is necessary. Behavior pattern identification sensor technology is expected to be developed and could replace passive infrared sensor that cause system error, giving security guard firm confidence for response. The principle of behavior pattern identification is similar to image identification, so those two technology could be integrated with tracking technology and radio identification technology of RFID for total monitoring system. For more efficient electronic security system, middle-ware's role is very important to integrate the technology of electronic security system, this could make possible of installing the integrated security system.

• The korean journal of orthodontics
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• v.41 no.6
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• pp.399-410
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• 2011

Objective: The purpose of this study was to evaluate the difference in frictional resistance among metal, ceramic, self-ligation brackets and coated or non-coated Ni-Ti archwires at various bracket-archwire angulations during the sliding movement of an orthodontic archwire, using an orthodontic sliding simulation device. Methods: Four types of bracket (Micro-arch Perpect Clear2 Clippy-C and Damon3 and 5 types of orthodontic archwire (0.014", 0.016", and 0.016" ${\times}$ 0.022" inch coated Ni-Ti, and 0.016" and 0.016" ${\times}$ 0.022" inch Ni-Ti) were used. Further, the bracket- archwire angles were set at 4 different angulations: $0^{\circ}$, $3^{\circ}$, $6^{\circ}$, and $9^{\circ}$. Results: The frictions from all the experimental groups were found to be significantly increased in order of self-ligation brackets, Micro-arch and Perpect Clear2 ($p$ < 0.001). The presence of a coat had no effect on the friction of the same sized archwires at $0^{\circ}$ and $3^{\circ}$ bracket-archwire angles ($p$ < 0.001). Coated archwires had significantly higher frictions than the same sized non-coated archwires at $6^{\circ}$ and $9^{\circ}$ bracket-archwire angles ($p$ < 0.001). The frictions increased significantly as the bracket-archwire angles were increased ($p$ < 0.001). Conclusions: The use of self-ligation brackets will be beneficial in clinical situations where a low frictional force is required. Further, in cases where crowding is not severe, the use of coated archwires should not cause problems. However, more additional explanation is required considering the fact that the damage of coated archwire and exposure of the metal portion in case of binding and notching and the effects of saliva were not taken into account.