• The korean journal of orthodontics
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• v.38 no.6
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• pp.376-387
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• 2008

Objective: The purpose of this study was to compare the three dimensional changes of tooth movement using four different types of maxillary molar distalization appliances; pendulum appliance (PD), mini-implant supported pendulum appliance (MPD), stainless steel open coil spring (SP) and mini-implant supported stainless steel open coil spring (MSP). Methods: These experiments were performed using the Calorific $machine^{(R)}$ which can simulate dynamic tooth movement. Computed tomography (CT) images of the experimental model were taken before and after tooth movement in 1 mm thicknesses and reconstructed into a three dimensional model using V-works $4.0^{TM}$. These reconstructed images were superimposed using Rapidform $2004^{TM}$ and the direction and amount of tooth movement were measured. Results: The mean reciprocal anchor loss ratio at the first premolar was 17 - 19% for the PD and SP groups. The appliances using mini-implants (MPD or MSP) resulted in less anchorage loss (7 - 8%). On application of a pendulum appliance or MPD, distalization was obtained by tipping rather than by bodily movement. Furthermore, the maxillary second molar tipped distally and bucally. But on application of MSP, distalization was achieved almost by bodily movement. Conclusions: Regarding tooth movement patterns during molar distalization, stainless steel open coil spring with indirect skeletal anchorage was relatively superior to other methods.

• Journal of Technology Innovation
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• v.21 no.2
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• pp.169-197
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• 2013

Despite many theoretical and empirical studies, general causality between IPRs system, firm technological innovation and financial performance is not clear. This study notices that the core factor to create financial performance is different by each industry. The study analyzed the effect of IPRs system on innovation and economic growth targeting 3 industries; pharmaceutical industry to which the basic track of creating performance is applied (strengthening IPRs${\rightarrow}$increasing R&D input/output${\rightarrow}$increasing sales); semiconductor industry where the relationship between stronger IPRs and R&D input/output is weak; and shipbuilding industry which has weak correlation between R&D and sales. It used panel data for 15 years since TRIPs when the patent institution in Korea reached up to the level of advanced countries, and applied the dynamic regression model which estimates the fixed effect model with difference-GMM. As a result, stronger IPRs increased R&D input/output, and financial performance in pharmaceutical industry, but has no influence on semiconductor and shipbuilding industries. That is, it is necessary to customize the construction of system and policy for strengthening IPRs by each industry, and unitary strengthening or weakening may have no significant impact on financial performance improvement in specific sectors.

• The Journal of the Acoustical Society of Korea
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• v.22 no.5
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• pp.375-382
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• 2003

Lip-reading technique based on bimodal is to enhance speech recognition rate in noisy environment. It is most important to detect the correct lip-image. But it is hard to estimate stable performance in dynamic environment, because of many factors to deteriorate Lip-reading's performance. There are illumination change, speaker's pronunciation habit, versatility of lips shape and rotation or size change of lips etc. In this paper, we propose the IIR filtering in time-domain for the stable performance. It is very proper to remove the noise of speech, to enhance performance of recognition by digital filtering in time domain. While the lip-reading technique in whole lip image makes data massive, the Principal Component Analysis of pre-process allows to reduce the data quantify by detection of feature without loss of image information. For the observation performance of speech recognition using only image information, we made an experiment on recognition after choosing 22 words in available car service. We used Hidden Markov Model by speech recognition algorithm to compare this words' recognition performance. As a result, while the recognition rate of lip-reading using PCA is 64%, Time-domain filter applied to lip-reading enhances recognition rate of 72.4%.

• The Korean Journal of Financial Management
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• v.27 no.1
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• pp.1-30
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• 2010

This paper tested the lead-lag relationship as well as the symmetric and asymmetric volatility spillover effects between international currency futures markets and cash markets. We use five kinds of currency spot and futures markets such as British pound, Australian and Canadian dollar, Brasilian Real and won/dollar spot and futures markets. daily closing prices covering from September 15, 2003 to July 30, 2009. For this purpose we employed dynamic time series models such as the Granger causality based on VAR and time-varying MA(1)-GJR-GARCH(1, 1)-M. The main empirical results are as follows; First, according to Granger causality test, we find that the bilateral lead-lag relationship between the five countries' currency spot and futures market. The price discover effect from currency futures markets to spot market is relatively stronger than that from currency spot to futures markets. Second, based on the time varying GARCH model, we find that there is a bilateral conditional mean spillover effects between the five currency spot and futures markets. Third, we also find that there is a bilateral asymmetric volatility spillover effects between British pound, Canadian dollar, Brasilian Real and won/dollar spot and futures market. However there is a unilateral asymmetric volatility spillover effect from Australian dollar futures to cash market, not vice versa. From these empirical results we infer that most of currency futures markets have a much better price discovery function than currency cash market and are inefficient to the information.

• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.449-460
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• 2021

ASVspoof 2017 deals with detection of replay attacks and aims to classify real human voices and fake voices. The spoofed voice refers to the voice that reproduces the original voice by different types of microphones and speakers. data augmentation research on image data has been actively conducted, and several studies have been conducted to attempt data augmentation on voice. However, there are not many attempts to augment data for voice replay attacks, so this paper explores how audio modification through data augmentation techniques affects the detection of replay attacks. A total of 7 data augmentation techniques were applied, and among them, dynamic value change (DVC) and pitch techniques helped improve performance. DVC and pitch showed an improvement of about 8% of the base model EER, and DVC in particular showed noticeable improvement in accuracy in some environments among 57 replay configurations. The greatest increase was achieved in RC53, and DVC led to an approximately 45% improvement in base model accuracy. The high-end recording and playback devices that were previously difficult to detect were well identified. Based on this study, we found that the DVC and pitch data augmentation techniques are helpful in improving performance in the voice spoofing detection problem.

• The KIPS Transactions:PartC
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• v.16C no.5
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• pp.653-660
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• 2009

A research for middleware of WSN can provide sensor applications with avoiding tight coupling of hardware, ease of development, and abstract data access. However, previous works have some limitations which should install their own middleware onto the all sensor nodes resulting in computational and communication overhead. In order to address it, we proposed a virtual sensor overlay network, called TinyONet-Lite which introduced virtual sensors to model a virtual counterpart of physical sensors. These virtual sensors dynamically grouped into an overlay network, Slice, which provides middleware services. We implemented TinyONet-Lite on mote class hardware with TinyOS. In accordance with experiments and comparison with existing researches, TinyONet-Lite was proved to show advantages of extensibility, dynamic service composition and reducing overhead.

• Journal of the Korean Home Economics Association
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• v.27 no.3
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• pp.173-182
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• 1989

이 연구의 목적은 전통적으로 남성 주도적인 전문직 진출을 희망하는 여대생(이 연구에서는 법률가 및 의사직, 이하 비 전통적인 여성이라 부름)과 전통적으로 여성 주도적인 전문직 진출을 준비중인 여대생 (이 연구에서는 교사 및 간호사직, 이하 전통적으로 여성 이라 부름)을 구분 할수 있는 개인의 성격 및 가족환경의 특성을 검토하는 것이었다. 남성 주도적인 전문직에 진출을 준비하거나 그 분야에 종사하는 여성들의 특성에 대한 연구가 많이 발표되었으나 그 특징들의 중요성이 상대적으로 얼마나 비중이 있는지는 연구되어 있지 않다. 발단론적 환경이론(Developmental-Contextualism)과 직업 발달에 대한 역동적 상호관계 모델(Dynamic Interaction Model)이 본 연구의 이론적 체계를 이루고 있다. 이 연구에 포함성의 위치, 심리적 남성특성, 출신가정의 사회경제수준, 그리고 부모의 뒷받침과 이해였다. ANOVA 결과에 의하면 비전통적인 여성들이 자아존중감, 학교성적 성취도, 내적 통제성, 심리적 남성특성, 그리고 출신가정의 사회경제수준 면에서 전통적인 여성에 비해 훨씬 높은 수준을 나타내었다. 단계적 분별 분석 (Stepwise Discriminant Analysis) 결과에 따르면, 심리적 남성 특성, 내적 통제성, 학교성적 성취도, 그리고 출신가정의 사회경제수준이 위 두집단의 여성들을 분별하는 가장 뛰어난 특성들이었으며 전체 표본의 76.99%가 이 요인들에 의해 정확하게 분류되었다. 이 연구의 결과를 토대로 볼 때, 역동적 상호관계모델은 여성의 직업발달을 연구하는데 있어서 이론정립과 검사에 유효한 도구로 보이며, 이 연구에 포함한 변수들은 비 전통적인 여성들의 특성을 정확하게 묘사하는데 상당한 공헌을 하고 있었다. 마지막으로, 비전통적인 여성들의 직업발달을 연구하는데 있어서 "능력특성군(Competency-related traits)"의 변수들을 좀 더 정확하게 분류할 필요가 있으며, 이 변수들과 여성의 직업발달의 관계를 자세히 연구할 필요가 있다고 본다.요가 있다고 본다.

• The Korean Journal of Emergency Medical Services
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• v.8 no.1
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• pp.169-178
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• 2004

본 연구의 목적은 응급구조사들이 긴 척추고정판을 이용하여 환자를 들어 올리는 3가지 다른 자세와 다른 3가지 부하 조건을 이용하여, 요추 4번과 5번의 압축력, 전단응력 그리고 합력의 변화를 동역학적 모델을 제시하기 위한 분석이다. 연구방법 : 36명의 남자가 본 연구의 실험에 자발적으로 동원되었으며, 나이는 평균 21.42세이고, 신장은 평균 174.05cm이며, 체중은 평균 78.05kg이다. 이 실험에서 부하 조건은 50, 70, 90kg이고, 들어 올리는 높이는 지상에서부터 95cm 이었으며, 들어 올리는 동안의 회전고리는 110cm이었다. 운동현상학적 자료는 2-D ProReflex Motion Capture Camera을 이용하였으며, sampling rate는 60Hz로 하였다. 결과 및 논의 : 동역학적 데이터 자료를 근거로 한 본 연구의 결론은 다음과 같다. Lunge 자세기술에서 전단응력과 합력 등이 최소의 stress로 요추 4번 5번에 미치는 것으로 나타났다. 그러나 Lunge 기술에서 압축력은 약간 증가되는 것으로 나타났다. 이 연구에서 Stooped 자세기술에서는 아주 큰 전단응력과 합력 등이 요추 4번, 5번 관절에 넓게 작용하는 것으로 나타났으며, 이는 들어 올리는 동작을 할 때 상해의 원인이 된다고 사료된다. 특히 응급구조사들이 들것을 들어 올릴 때 너무 큰 전단응력이 요추 4번, 5번 관절에 작용을 하면 비정상적으로 병리학상 또는 해부학상 신체적변화가 온다고 해석할 수 있다. 그래서 응급구조사들에게 들것을 들어올리는 stooped 자세는 아주 크고 많은 합력 작용하기 때문에 권고될만한 기술이 아니라고 해석 된다. Squat 자세에서 중간 정도의 압축력, 전단응력 그리고 합력이 작용된다. 만약 응급구조사가 전단응력 그리고 합력이 요추에 미치는 영향이 가장 걱정된다면, lunge 자세가 두 가지 힘을 줄여줄 수 있다고 사료된다. 마지막으로 응급구조사가 들것을 들어올리는 데는 squat 자세 기술이 가장 좋다고 사료 된다.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.6
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• pp.627-633
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• 1999

In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a ？3-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. When the environmental condition (antigen) changes, a robot selects an appropriate behavior strategy (antibody). And its behavior strategy is stimulated and suppressed by other robot using communication (immune network). Finally much stimulated strateby is adopted as a swarm behavior strategy. This control scheme is based on clonal selection and immune network hypothesis, and it is used for decision making of optimal swarm strategy. Adaptation ability of robot is enhanced by adding T-cell model as a control parameter in dynamic environments.

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.17-27
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• 2017

Recently, as cyber attacks have been activated, many such attacks have come into contact with various media. Research on security engineering and reverse engineering is active, but there is a lack of research that integrates them and applies attack systems through cost effective attack engineering. In this paper, security - enhanced information systems are developed by security engineering and reverse engineering is used to identify vulnerabilities. Using this vulnerability, we compare and analyze lifecycle models that construct or remodel attack system through attack engineering, and specify structure and behavior of each system, and propose more effective modeling. In addition, we extend the existing models and tools to propose graphical attack specification models that specify attack methods and scenarios in terms of models such as functional, static, and dynamic.