• Journal of Acupuncture Research
• /
• 제18권2호
• /
• pp.67-78
• /
• 2001

The aim of this study was to examine the effects of low frequency electroacupuncture(EA) at the $B_{62}$ (Shinmaek) $K_6$(Chohae) on vascular dementia in humans using nonlinear dynamics. Electroencephalogram(EEG) is a multi-scaled signal consisting of several components of time series with different dominant frequency ranges and different origins. Nonlinear measures of the EEG like the correlation dimension ($D_2$) and the first positive Lyapunov exponent ($L_1$) reflect the complexity of the EEG. In this study, $D_2$ was used as a measure of complexity. Sixteen channel EEG study was carried out in six subjects (5 females and 1 males; $age=83.83{\pm}7.19years$). We found that the baseline $D_2$ values of the EEG at F4 and F8 channels (P<0.01) were lowered than during the acupuncture treatment, indicating decreased complexity of the EEG. However, the comparison with that before and after the treatment shows no significant differences in all channels.

• 인간행동과 음악연구
• /
• 제12권1호
• /
• pp.23-42
• /
• 2015

본 연구는 아동 및 청소년을 대상으로 연령과 음악 경험에 따라 화음 전개 복잡성에 대한 선호도가 어떻게 달라지는지 그 특성을 알아보고자 하였다. 이를 위해 초, 중, 고등학교에 재학 중인 총 684명의 아동 및 청소년을 대상으로 실험이 실시되었다. 본 연구를 위해 4마디의 멜로디가 연구자에 의해 작곡되었고, 협화적 화음과 비화성음의 비중, 화음 해결의 즉각성 등을 바탕으로 화음 전개의 난이도가 4단계로 구성되었다. 대상자들은 4개의 음악 자극을 듣고 지각되는 복잡성과 화음 선호도의 정도를 표시하였다. 대상자들의 평가를 분석한 결과, 청소년의 연령에 따른 단계별 화음 선호도에 유의한 차이가 있었다. 선호 점수에 있어서 초등학생은 모든 단계의 화음에 높은 선호를 보인 반면, 중, 고등학생은 화음 복잡성이 증가할수록 유의하게 낮은 선호도를 보였다. 연령 외에도 악기 연주 훈련 기간 역시 화음 선호도에 유의한 영향을 미치는 것으로 나타났다. 악기 연주 훈련을 보다 오래 받은 그룹이 짧게 받은 그룹보다 화음 복잡성 변화를 보다 민감하게 지각하여 개인이 수용할 수 있는 복잡성 수준이 보다 높은 것으로 나타났으며, 이는 연령이 많을 수록 더욱 분명하게 나타나는 경향이 있었다. 이러한 연구 결과는 아동 및 청소년을 위한 감상음악 선곡 시 적절한 난이도의 화음을 선택할 수 있는 기초자료로써 의의를 갖는다.

• Toxicological Research
• /
• 제17권
• /
• pp.1-9
• /
• 2001

Some would argue that the search for the origin and treatment of this disease will continue over the next quarter century in much the same manner as it has in the recent past, by adding further layers of complexity to a scientific literature that is already complex almost beyond measure. But we anticipate otherwise: those researching the cancer problem will be practicing a dramatically different type of science than we have experienced over the past 25 years. Surely much of this change will be apparent at the technical level. But ultimately, the more fundamental change will be conceptual.

• ETRI Journal
• /
• 제16권3호
• /
• pp.27-41
• /
• 1994

This paper provides a performance study of multistage interconnection networks in packet switching environment. In comparison to earlier work, the model is more extensive - it includes several parameters such as multiple-packet messages, variable buffer size, and wait delay at a source. The model is also uniformly applied to several representative networks and thus provides a basis for fair comparison as well as selection of optimal values for parameters. The complexity of the model required use of simulation. However, a partial analytical model is provided to measure the congestion in a network.

• Journal of Power Electronics
• /
• 제10권3호
• /
• pp.300-305
• /
• 2010

This paper presents a two Hall sensor method for rotor angle detection in permanent magnet synchronous motors (PMSM). To minimize the implementation complexity, the system is designed to measure the edge field of permanent magnet pieces. However, there are nonlinearities in the measured values of the edge field. In this work, an angle correction algorithm is proposed, and the improvements in accuracy are verified through experiments. Finally, a field orientation controller is constructed with the proposed angle detection algorithm.

• Journal of the Korean Data and Information Science Society
• /
• 제15권4호
• /
• pp.891-898
• /
• 2004

An effective video indexing is required to manipulate large video databases. Most algorithms for video indexing have been commonly used histograms, edges, or motion features. In this paper, we propose an efficient algorithm using the luminance projection for video retrieval. To effectively index the video sequences and to reduce the computational complexity, we use the key frames extracted by the cumulative measure, and compare the set of key frames using the modified Hausdorff distance. Experimental results show that the proposed video indexing and video retrieval algorithm yields the higher accuracy and performance than the conventional algorithm.

• 대한수학회논문집
• /
• 제38권2호
• /
• pp.491-507
• /
• 2023

The aim of this paper is to study the descriptive set-theoretic complexity of the Hewitt-Stromberg measure and dimension maps.

• Journal of the Optical Society of Korea
• /
• 제19권4호
• /
• pp.357-362
• /
• 2015

We examine the principle of a modified Pound-Drever-Hall (PDH) technique to measure the free spectral range of a Fabry-Perot etalon (FPE). The FPE's periodic transmission of phase-modulated light allows us to adopt a sampling theorem to develop a new relationship for the PDH error signal. This leads us to find the key parameters governing the measurement accuracy: the phase modulation index ${\beta}$ and the FPE finesse. Without any additional complexity for background noise reduction, we achieve a measurement accuracy of 0.5 ppm. The improvement is mainly attributed to the wide-band phase modulation approaching ${\beta}=10$, and partly to the use of both reflected and transmitted light from the FPE and good FPE finesse.

• 대한교통학회지
• /
• 제12권1호
• /
• pp.43-54
• /
• 1994

The major concern of this paper is to investigate the properties of a stochastic equilibrium for each model system in terms of a consumer welfare measure. The primary assumption for this study is that a trip-maker would choose the trip from his origin zone which maximizes his personal welfare. This assumption, finally, leads to a singly constrained gravity model. The consumer welfare measure is derived from the concept of expected welfare of randomly sampled trip-makers. Each of the four different models considered in this paper is differentiated depending on the complexity of its model or the definition of its travel function. In this study, three different regions are chosen for the purpose of taking into account the effects of different zone-systems on the properties of a stochastic equilibrium : (i) Archerville region (5 zone) ; (ii) San Francisco Bay regions (30 zones) ; (iii) Houston, TX region (199 zones). It is concluded that almost identical, "global" consumer welfare values can be obtained in some cases of the gravity-type trip distribution models based on a stochastic equilibrium.

• 전기의세계
• /
• 제25권5호
• /
• pp.70-74
• /
• 1976

In this paper, the problem of controlling deterministic contimuous linear system with a slightly modified quadratic performance criteria is studied. When the number of out put variables is much lesser then that of state variables, either the controller becomes complex or the performance measure becomes much higher with only output feedback. So the design philosphy treated in this paper lies in finding a compromising point between the controller complexity and the performance measure. thd controller is composed of stasic plus dynamic compensator with order equal to the mtmber of output variables. Several unknowns are unknown parameters are bundled into one, and using Pontryagin's minimum principle, conditions and formula for optimum control are induced which are different from that of Kalman optimal regulator.