• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.511-517
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• 2022

Recently, due to rapid climate change, the population of honey bees has decreased, posing a great threat to the existence of the Earth's ecosystem. In particular, the colony collapse phenomenon in which bees disappeared nationwide in early 2022 had devastating consequences for beekeepers. In order to solve the problems of beekeeping due to climate change, it is urgent to develop a system that can monitor the situation inside the hive through various IoT sensors. This paper develops a system that can measure the activity of bees inside the hive and uses it to measure the number of times of entry and exit of the hive. The data measured by the developed system can be monitored in real time on a smartphone through the cloud server. The system developed in this paper can monitor the ecology of bees according to climate change and measure internal and external bee activities. Using this method, it is possible to check in advance for the colony collapse phenomenon in which bees disappeared in early 2022. This is very meaningful in that it presents an alternative that can identify the cause of the problem through early detection.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.834-837
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• 2005

In this paper, we describe the method of non-invasive blood pressure measurement using pulse wave transit time(PWTT). PWTT is a new parameter involved with a vascular that can indicate the change of BP. PWTT is measured by continuous monitoring of ECG and pulse wave. No additional sensors or modules are required. In many cases, the change of PWTT correlates with the change of BP. We measure pulse wave using the photo plethysmograph(PPG) sensor in an earlobe and we measure ECG using the ECG monitoring device our made in the chest. The measurement device for detecting pulse wave consists of infrared LED for transmitted light illumination, pin photodiode as light detector, amplifier and filter. We composed 0.5Hz high pass, 60Hz notch and 10Hz low pass filter. ECG measurement device consists of multiplexer, amplifier, filter, micro-controller and RF module. After amplification and filtering, ECG signal and pulse wave is fed through micro-controller. We performed the initial work towards the development of ambulatory BP monitoring system using PWTT. An earlobe is suitable place to measure PPG signal without the restraint in daily work. From the results, we can know that the dependence of PWTT on BP is almost linear and it is possible to monitoring an individual BP continuously after the individual calibration.

• 한국멀티미디어학회논문지
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• 제6권5호
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• pp.797-804
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• 2003

장면 전환검출 (scene change detection)은 영상 정보의 색인 (indexing) 및 검색을 위한 전처리로서 비디오 검색 시스템의 전체 성능을 좌우하는 중요한 기술로 현재 많은 연구가 진행되고 있다. 본 논문에서는 급격한 움직임 및 조명 변화, 빠르게 연속적으로 등장하는 장면 전환에 강건한 급격한 장면 전환 검출 기법과 디졸브, 페이드 등의 장면 전환을 보다 효과적으로 검출할 수 있는 점진적인 장면 전환 검출 기법 및 추출된 셧 (shot)의 내용을 DCT DC 이미지 버퍼링과 누적 히스토그램 교차 함수 (accumulative histogram intersection measure)에 의해 대표 프레임으로 추출하는 새로운 알고리즘을 제안하고, 모의 실험 결과 기존 방식에 비해 보다 우수한 성능을 보임을 입증하였다.

• 한국멀티미디어학회논문지
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• 제21권5호
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• pp.609-616
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• 2018

In this paper, we designed a multimodal bio-signal measurement system to observe changes in the brain nervous system and vascular system during sleep. Changes in the nervous system and the cerebral blood flow system in the brain during sleep induce a unique correlation between the changes in the nervous system and the blood flow system. Therefore, it is necessary to simultaneously observe changes in the brain nervous system and changes in the blood flow system to observe the sleep state. To measure the change of the nervous system, EEG, EOG and EMG signal used for the sleep stage analysis were designed. We designed a system for measuring cerebral blood flow changes using functional near-infrared spectroscopy. Among the various imaging methods to measure blood flow and metabolism, it is easy to measure simultaneously with EEG signal and it can be easily designed for miniaturization of equipment. The sleep stage was analyzed by the measured data, and the change of the cerebral blood flow was confirmed by the change of the sleep stage.

• 대한수학회보
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• 제55권2호
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• pp.561-572
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• 2018

In this paper we consider the concept of statistical causality in continuous time between flows of information, represented by filtrations. Then we relate the given concept of causality to the equivalent change of measure that plays an important role in mathematical finance. We give necessary and sufficient conditions, in terms of statistical causality, for extremality of measure in the set of martingale measures. Also, we have considered the extremality of measure which involves the stopping time and the stopped processes, and obtained similar results. Finally, we show that the concept of unique equivalent martingale measure is strongly connected to the given concept of causality and apply this result to the continuous market model.

• 반도체디스플레이기술학회지
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• 제21권2호
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• pp.107-111
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• 2022

In this paper, a plastic film type submersion sensor capable of measuring submersion speed was developed. This submersion sensor is designed as a capacitive type, and it is a sensor that outputs the change in capacitance between the electrode of the submersion sensor and the grounded body as a voltage through a C-V(capacitance-voltage) converter. We developed an submersion sensor in which two electrodes of different lengths are connected in parallel to measure the submersion speed accurately by minimizing the influence of noise such as contamination. When both electrodes of the submersion sensor are exposed to water, the rate of change of water level suddenly increases, so the submersion speed is measured by measuring the time to this point. Since the difference in length between the two electrodes of the submersion sensor does not change in any case, it is possible to accurately measure the submersion speed.

• 한국농림기상학회지
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• 제1권1호
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• pp.36-40
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• 1999

A new method was developed to measure underground water level with high reliability. The principle of new method was to detect a change of a buoyant force according to change in water level of underground water measured by the use of a straingage load cell. Field test of the instrument was carried out in Cheju Island. The results were as follows; 1) The present study provided a possibility to develop a new underground water level meter. 2) This new instrument accomplished high reliability at field test in Cheju Island. 3) There is possibility of development of water level meter which measure various range of water level to detect a weight change of a buoyant forcd.

• Journal of Korea Trade
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• 제25권3호
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• pp.48-64
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• 2021

Purpose - This study examined the effect of tariff cuts on productivity in Korea's manufacturing industries and the effect of initial productivity level before tariff cuts on productivity improvement after tariff cuts. We also attempted to identify whether import-driven or export-driven factors are more important for productivity improvement, especially in low productivity industries. Design/methodology - Since tariff reduction is a policy decision that can affect cross-industry, its impact is spread across all industries beyond the scope of a single firm through the input and output network of industry structure. Accordingly, we proposed a new method to measure the change in productivity to reflect the impact of tariff cuts across industries. Through an Armington CGE analysis, changes in endogenous variables can be directly measured after the exogenous shock of tariff reduction, and the amount of movements in productivity triggered by tariff cuts can also be calculated. We can thus assess the effectiveness of exogenous policy, such as tariff cuts, through the difference between the benchmark and counterfactual values of endogenous variables. Findings - This study confirmed that tariff reduction positively affected productivity improvement in Korea's manufacturing industries. It also confirmed that productivity gains occur in Korea's leading export industries. Finally, greater productivity gains were recorded in the group with additional high-export-share or high-import-share conditions for low productivity industries. These results are, in a limited sense, consistent with the existing studies that emphasize the importance of exports and imports on productivity improvement, especially for low productivity industries. Originality/value - The results of our experiments are different from those of non-CGE studies, which measure the industry-level change in productivity with dummy coefficients, in terms of directly calculating the amount of change in productivity. In addition, we propose that the Armington CGE model is more appropriate than the Melitz CGE model to directly measure the productivity after tariff cuts. This is because the Melitz CGE model assumes the given specific productivity density, which does not change after an overall drop of tariffs. To the best of our knowledge, this approach to directly calculating productivity by reflecting the impact of tariff reduction across industries through CGE analysis, is unprecedented in this literature.

• 한국농림기상학회지
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• 제4권4호
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• pp.197-202
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• 2002

A new method is used to estimate the amount of water evaporation from Class A Pan with higher precision and accuracy. The principle of method is to detect the weight change of a buoyant sinker resulting from a change in water level of Class A Pan. A strain-gauge load cell is used to measure the weight change. Field observation of evaporation was done at Pohang Meteorological Station from June 24 to August 4, 2002. By using this new method, it is possible to measure hourly evaporation accurately even under a strong solar radiation and wind disturbance, enabling a direct comparison of evaporation with other meteorological elements. At night, under low humidity and high wind speed conditions, more evaporation was recorded than during daytime. Maximum evaporation rates observed during this period exceed 1.0 mm/hour under the sunny and windy conditions with low humidity. To understand relationships between meteorological elements and latent heat flux at ground level, we suggest intensive held experiments using high accuracy evaporation recording instruments with hourly time interval.

• 한국정보시스템학회지:정보시스템연구
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• 제17권3호
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• pp.25-37
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• 2008

In a fault tree analysis, an uncertainty importance measure is often used to assess how much uncertainty of the top event probability (Q) is attributable to the uncertainty of a basic event probability ($q_i$), and thus, to identify those basic events whose uncertainties need to be reduced to effectively reduce the uncertainty of Q. For evaluating the measures suggested by many authors which assess a percentage change in the variance V of Q with respect to unit percentage change in the variance $v_i$ of $q_i$, V and ${\partial}V/{\partial}v_i$ need to be estimated analytically or by Monte Carlo simulation. However, it is very complicated to analytically compute V and ${\partial}V/{\partial}v_i$ for large-sized fault trees, and difficult to estimate them in a robust manner by Monte Carlo simulation. In this paper, we propose a method for evaluating the measure using discretization technique and Monte Carlo simulation. The proposed method provides a stable uncertainty importance of each basic event.