• Proceedings of the Korea Society of Design Studies Conference
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• 2005.10a
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• pp.64-65
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• 2005

• Journal of the HCI Society of Korea
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• v.12 no.1
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• pp.25-32
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• 2017

The purpose of this study is to evaluate the effectiveness of one-handed interaction modes for supporting the dead zone that users must be difficulty in performing the touch manipulation with only one hand. For the purpose, this study analyzed two existing one-handed modes in iPhone and Android smartphones, and proposed and implemented two additional one-handed modes. In order to investigate effectiveness of the one-handed modes, we performed the experiment that compared normal touch mode with the four one-handed modes. Experimental results showed that all one-handed modes required more time than normal touch mode because of the time requiring in both mode change and recognition. However, the participants had difficulty in manipulating continuous touches at dead zone area with only normal touch. Moreover, the subjective satisfaction was high in one-handed modes thanks to touch convenience and smooth transition effects in mode change. In special, the one-handed mode at iPhone was the most effective out of the tested modes.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.425-430
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• 2006

현재 대부분의 데스크탑 시스템에서 사용자는 단지 하나의 마우스를 사용해서 컴퓨터와 상호작용을 하고 있다. 본 논문에서는 각각의 손으로 동시에 두 개의 마우스들을 사용할 때, 작업 성능에 대한 효과를 살펴보고자 한다. 본 논문에서의 실험에서는 데스크탑 환경에 기반한 간단한 게임 (날아오는 총알 피하기와 잡기)에서 세 개의 독립 변수들로 한 손 또는 양 손 사용 여부, 주위 상황(총알)의 변화 속도, 그리고 두 커서(캐릭터)들간의 거리 차이를 사용하고, 종속 변수로 사용자의 작업 성능(부딪친 총알 개수)을 측정하였다. 실험 결과에 의하면, 두 커서 (또는 두 캐릭터)와의 동시 상호작용이 필요할 때 한 손보다는 양 손을 사용할 때의 작업 성능이 통계적으로 유의하게 좋았고, 두 커서 사이에 거리가 멀수록, 그리고 총알의 속도가 느릴수록 작업 성능은 유의하게 좋았다. 독립 변수들 사이에는 서로 유의한 교호작용이 나타나지 않았는데, 이것은 작업 성능에 대한 양손의 효과가 다른 독립 변수들의 각 레벨과는 상관이 없었다는 것을 의미한다.

• BMB Reports
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• v.29 no.1
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• pp.1-10
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• 1996

The binding interaction of ethidium to a series of synthetic deoxyoligonucleotides containing a B-Z junction between left-handed Z-DNA and right-handed B-DNA, was studied. The series of deoxyoligonucleotides was designed so as to vary a dinucleotide step immediately adjacent to a B-Z junction region. Ethidium binds to the right-handed DNA forms and hybrid B-Z forms which contain a B-Z junction, in a highly cooperative manner. In a series of deoxyoligonucleotides, the binding affinity of ethidium with DNA forms which were initially hybrid B-Z forms shows over an order of magnitude higher than that with any other DNA forms, which were entirely in B-form DNA The cooperativity of binding isotherms were described by an allosteric binding model and by a neighbor exclusion model. The binding data were statistically compared for two models. The conformation of allosterically converted DNA forms under binding with ethidium is found to be different from that of the initial B-form DNA as examined by CD spectra. The ratio of the binding constant was interestingly correlated to the free energy of base unstacking and the conformational conversion of the dinucleotide. The more the base stacking of the dinucleotide is unstable, or the harder the conversion of B to A conformation, the higher the ratio of the binding constant of ethidium with the allosterically converted DNA forms and with the initial B-Z hybrid forms. DNA sequence around a B-Z junction region affects the binding affinity of ethidium. The results in this study demonstrate that ethidium could preferentially interact with unusual DNA structures.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.140-143
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• 2012

사람간의 상호작용에서 손은 중요한 역할을 담당하고 있기 때문에, 사람과 컴퓨터 사이의 인터페이스에 관한 연구에서 역시 손을 이용한 자연스러운 상호작용은 중요한 화두 중 하나이다. 따라서 본 논문에서는 손 기반 인터페이스를 위한 손 모양 인식 방법을 제안한다. 제안하는 방법은 비전 기반의 방법을 이용하기 때문에 사용자의 몰입을 방해할 수 있는 마커 혹은 센서의 부착을 요구하지 않으며, 간단하지만 효과적인 방법을 사용함으로써 실시간 연산을 보장한다. 또한 사용자의 양 손을 추적하고 손의 모양을 인식함으로써, 보다 자연스러운 양손 기반의 상호작용을 제공한다.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.386-390
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• 2014

Purpose: We aimed to investigate whether visuomotor function would be modulated, when healthy subjects performed tracking task after tDCS application over the primary sensorimotor cortex (SM1) in the non-dominant hemisphere. Methods: Thirty four right-handed healthy participants were enrolled, who randomly and evenly divided into two groups, real tDCS group and sham control group. Direct current with intensity of 1 mA was delivered over SM1 for 15 minutes. After tDCS, tracking task was measured, and their performance was calculated by an accuracy index (AI). Results: No significant difference in AI at the baseline between the two groups was observed. The AI of the real tDCS group was significantly increased after electrical stimulation, compared to the sham control group. Two way ANOVA with repeated measurement showed a significant finding in a large main effects of time and group-by-repeated test interaction. Conclusion: This study indicated that application of the anodal tDCS over the SM1 could facilitate higher visuomotor coordination, compared to sham tDCS group. These findings suggest possibility that tDCS can be used as adjuvant brain modulator for improvement of motor accuracy in healthy individuals as well as patients with brain injury.

• The Journal of Korean Physical Therapy
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• v.27 no.1
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• pp.38-42
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• 2015

Purpose: Accuracy and variability of movement in daily life require synchronization of muscular activities through a specific chronological order of motor performance, which is controlled by higher neural substrates and/or lower motor centers. We attempted to investigate whether transcranial direct current stimulation (tDCS) over primary sensorimotor areas (SM1) could influence movement variability in healthy subjects, using a tapping task. Methods: Twenty six right-handed healthy subjects with no neurological or psychiatric disorders participated in this study. They were randomly and equally assigned to the real tDCS group or sham control group. Direct current with intensity of 1 mA was delivered over their right SM1 for 15 minutes. For estimation of movement variability before and after tDCS, tapping task was measured, and variability was calculated as standard deviation of the inter-tap interval (SD-ITI). Results: At the baseline test, there was no significant difference in SD-ITI between the two groups. In two-way ANOVA with repeated measurement no significant differences were found in a large main effect of group and interaction effect between two main factors (i.e., group factor and time factor (pre-post test)). However, significant findings were observed in a large main effect of the pre-post test. Conclusion: Our findings showed that the anodal tDCS over SM1 for 15 minutes with intensity of 1 mA could enhance consistency of motor execution in a repetitive-simple tapping task. We suggest that tDCS has potential as an adjuvant brain facilitator for improving rhythm and consistency of movement in healthy individuals.

• Physical Therapy Korea
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• v.23 no.3
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• pp.48-56
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• 2016

Background: Recently, there has been an emphasis on the use of interventions with biofeedback information for the maintenance or correction of posture. Objects: This study assessed the change of trunk posture and trunk muscle activation when people exhibiting postural kyphosis performed visual display terminal work with or without a contact feedback device (CFD). Methods: Eighteen right-handed individuals were recruited. Thoracic angle and right thoracic erector spinae (TES) muscle amplitude were analyzed. There were two sessions in these experiments. The control session involved 16 minutes of typing without a CFD, and the CFD session involved 16 minutes of typing with a CFD. The visual analog scale score was analyzed with a paired t-test, and the kinematic and electromyography data were analyzed through two-way repeated analysis of variance. Results: The paired t-tests revealed that subjects had significantly less pain after the CFD sessions than after the control sessions (p<.05). Significant main effects by session and by time were observed in the thoracic kyphosis angle (p<.05). There was a significant session${\times}$time interaction for TES amplitude (p<.05), along with significant main effects by session and by time (p<.05). Conclusion: The CFD caused people with postural kyphosis to straighten and to activate their TES continuously, even though they were habituated to bend their bodies forward. Therefore, the CFD was a beneficial treatment tool.