• 한국멀티미디어학회논문지
• /
• 제17권12호
• /
• pp.1494-1502
• /
• 2014

Since smartphones are utilized in the ranges from personal usages to governmental data exchanges, known but not patched vulnerabilities in smartphone operating systems are considered as major threats to the public. To minimize potential security breaches on smartphones, it is necessary to estimate possible security threats. So far, there have been numerous studies conducted to evaluate the security risks caused by mobile devices qualitatively, but there are few quantitative manners. For a large scale risk evaluation, a qualitative assessment is a never ending task. In this paper, we try to calculate relative risk levels triggered by software vulnerabilities from unsecured smartphone operating systems (Android and iOS) among 51 Asian countries. The proposed method combines widely accepted risk representation in both theory and industrial fields. When policy makers need to make a strategic decision on mobile security related agendas, they might find the presented approach useful.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1995년도 제12회 음성통신 및 신호처리 워크샵 논문집 (SCAS 12권 1호)
• /
• pp.69-72
• /
• 1995

In this paper, a new approach for Korean connected digits recognition using the spatio-temporal neural network is reported. The data of seven digits phone numbers are used in the recognition of connected words, and in the initial experiment, digit recognition rate of 28% was achieved. In this paper, to increase recognition rate, two different approaches are analyzed. In the first system, to compensate the STNN's own defect and to emphasize the Korean word's phonic characters, the starting point of phone is pointed by comparing the average magnitude and zero-crossing rate and the ending point is pointed by comparing only zero-crossing rate. The digit recoginiton rate increased to 61%. Also, in the second system, to consider fact that same word's phone is varied severally, the number of STNN's of each word is increased from one to five, and then the varied same word's phones can be included to the increased STNN's. The digit recogniton rate of connected words increased to 89%.

• 한국인지과학회:학술대회논문집
• /
• 한국인지과학회 2000년도 한글 및 한국어 정보처리
• /
• pp.279-284
• /
• 2000

핵심개념 기반의 분석 시스템은 기존의 CFG형태로 기술된 문법의 양을 현저히 줄이고 간투어, 중복발화등과 같은 파싱 불필요 성분을 처리하는 루틴을 개선해 파서의 부담을 줄인 분석 방법이다. 핵심개념 기반 분석 시스템은 동사를 기준으로 문법을 기술한다. 따라서 발화자의 사투리 등에 의해서 동사 정보를 상실한 문장은 분석이 되지 않는 문제점을 가지고 있으며 또한, 문장 분석시 분석 문법을 구성할 수 없는 짧은 발화문같은 경우에도 분석을 하지 못하는 문제점을 가지고 있다. 이러한 문제점들을 해결하기 위해서 본 논문에서는 발화문의 예를 작성해 놓은 예문사전과 발화문이 가지고 있는 종결형 정보를 이용해서 그러한 문제를 해결하고 분석의 정확성을 높였다.

• 음성과학
• /
• 제3권
• /
• pp.156-166
• /
• 1998

In this paper, I would like to propose a dividing method by estimating the inflection points and the average magnitude energy in speech signals. The method proposed in this paper gave not only a satisfactory solution for the problems on dividing method by zero-crossing rate, but could estimate the feature of the transient period after dividing the starting point and transient period in speech signals before steady state. In the results of the experiment carried out with monosyllabic speech, it was found that even through speech samples indicated in D.C. level, the staring and ending point of the speech signals were exactly divided by the method. In addition to the results, I could compare with the features, such as the length of transient period, the short term energy, the frequency characteristics, in each speech signal.

• 디지털산업정보학회논문지
• /
• 제12권1호
• /
• pp.43-50
• /
• 2016

This paper is on an acoustic echo canceller solving the double-talk problem by using the blind signal separation technology. The acoustic echo canceller may be deteriorated or diverged during the double-talk period. So we use the blind signal separation to detect the double talking by separating the near-end speech signal from the mixed microphone signal. The blind signal separation extracts the near-end signal from dual microphones by the iterative computations using the 2nd order statistical character in the closed reverberation environment. By this method, the acoustic echo canceller operates irrespective of the double-talking. We verified performances of the proposed acoustic echo canceller in the computer simulations. The results show that the acoustic echo canceller with this algorithm detects the double-talk periods well, and then operates stably without diverging of the coefficients after ending the double-talking. The merits are in the simplicity and stability.

• 제어로봇시스템학회논문지
• /
• 제12권10호
• /
• pp.1012-1017
• /
• 2006

By breaking the symmetry of the velocity profile in the S-curve, we developed a fast starting and smooth ending motion profile, named asymmetric S-curve(AS-curve). The problem for generating motion profile is formulated, and the algorithm for the AS-curve is derived and the flow chart of the AS-curve is illustrated. By various simulations, the derived algorithm is tested and shows the validity. This AS-curve can be applied to the high precision machines where fast and vibrationless motion is required in the near future.

• 한국정밀공학회지
• /
• 제20권12호
• /
• pp.142-147
• /
• 2003

Mechanical properties of the materials used for transportations and industrial machinery under high strain rate loading conditions such as high impact loading are required to provide appropriate safety assessment to varying dynamically leaded mechanical structures. The Split Hopkinson Pressure Bar(SHPB) technique with a special experimental apparatus can be used to obtain the material behavior under high strain rate ]ending conditions. In this paper, the dynamic deformation behavior of a brass under both high strain rate compressive loading conditions has been determined using the SHPB technique.

• 대한의용생체공학회:의공학회지
• /
• 제6권2호
• /
• pp.23-28
• /
• 1985

In this paper, the the duration of horizontall saccadic eye movement is studied alls measurement system is designed using microprocessor to obtain the quantitized data The duration is measured using the beginning and ending points of the saccadic velocity threshold. The results obtained are as follows. 1. The average duration of the saccade for angle displacement of 0$^{\circ}$ to 20$^{\circ}$ lies between 25 and 60 msec, and represents the increasing curve except 9$^{\circ}$ and 12$^{\circ}$ 2. The average duration lfor angle displacement of 5$^{\circ}$,10$^{\circ}$,15$^{\circ}$, and 20$^{\circ}$ is 40, 48, 57.5, and 62 msec, respectively. 3. Nasal movement has a little longer duration than temporeal movement. 4. The duration is not concerned with subject's will.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.314-316
• /
• 2001

This paper present the position control method for the application of permanent magnet linear synchronous motor. Controller is designed as a conventional P-PI controller, but the extra information is used such as velocity and acceleration from motion profiles. The profiles comes from S-Curve which is an optimized point-to-point motion profiles to achieve fast motions with minimum vibration[2]. In this application, the targets of the position control are maximum 10um position error within 10msec after respective ending point of position profiles. The implementation of the controller has been done in full digital way. All the controller is designed on the DSP TMS320VC33 control board. To prove performance of the controller, the experiment was performed with a servo linear motor.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 E
• /
• pp.1727-1730
• /
• 1997

This paper describes the surge calculations on cable cores and sheaths when an unit step surge is applied in a cable core. It is clear that the maximum core voltage appears at the ending point and maximum sheath voltage is induced at the sending points. It appears that the smaller grounding resistance can offer results having some trends which larger core voltage appears at the end point and smaller voltage is induced at the sending point.