• 한국과학교육학회지
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• 제44권1호
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• pp.29-38
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• 2024

본 연구에서는 이언 해킹(Ian Hacking)의 실험 철학에 대한 철학적 관점을 탐구하고 이 관점이 학교 실험 교육에 미칠 영향에 대한 논의하였다. 그간 다수의 철학자들은 실험이 이론을 검증할 때에만 중요하다는 이론 선행적인 관점을 주장하였다. 이와 마찬가지로 학교 교육에서도 실험의 주요 목적은 이론의 확인과 입증에 초점을 맞춘 관점이 주류를 이룬 것으로 보인다. 그러나 이러한 이론 선행적인 관점과는 대조적으로 해킹을 포함한 실험 철학자들은 실험 자체가 자율성과 생명력을 갖는다는 주장을 제안하였다. 해킹은 개입하기와 조작하기를 통해 실험의 이론 자율적인 성격을 강조하면서 실험에서 그동안 상대적으로 간과되었던 도구 사용, 재료, 과학자의 솜씨와 같은 요소들의 중요성을 강조하였고, 과학 활동에서의 실험의 역할과 그의 중요성을 재고하였다. 본 연구에서는 이러한 철학적 입장이 학교 실험교육에도 적용할 수 있는 것으로 보았으며, 본 연구에서 제시하는 현상중심의 관점을 통해 도구 사용, 실험자의 개입, 모델링 활동과 같은 과학적 실천을 가르치는 데 도움이 될 것으로 예상한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.159-162
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• 2005

Random Early Detection (RED), one of the most well-known Active Queue Management (AQM), has been designed to substitute Tail Drop and is nowadays widely implemented in commercially available routers. RED algorithm provides high throughput and low delay as well as a solution of global synchronization. However RED is sensitive to parameters setting, so the performance of RED, significantly depends on the fixed parameters. To solve this problem, the Adaptive RED (ARED) algorithm is suggested by S. Floyd. But, ARED also uses fixed parameters like target-queue length; it is hard to respond to bursty traffic actively. In this paper, we proposed AQM algorithm based on the variation of current queue length in order to improve adaptability about burst traffic. We measured performance of proposed algorithm through a throughput, marking-drop rate and bias phenomenon. In experimentation, we raised a packet throughput as reduced packet drop rate, and we confirmed to reduce a bias phenomenon about bursty traffic.

• Structural Engineering and Mechanics
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• 제47권5호
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• pp.679-700
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• 2013

Two new predictive design methods are presented in this study. The first is a hybrid method, called neuro-fuzzy, based on neural networks with fuzzy learning. A total of 280 experimental datasets obtained from the literature concerning concentric punching shear tests of reinforced concrete slab-column connections without shear reinforcement were used to test the model (194 for experimentation and 86 for validation) and were endorsed by statistical validation criteria. The punching shear strength predicted by the neuro-fuzzy model was compared with those predicted by current models of punching shear, widely used in the design practice, such as ACI 318-08, SIA262 and CBA93. The neuro-fuzzy model showed high predictive accuracy of resistance to punching according to all of the relevant codes. A second, more user-friendly design method is presented based on a predictive linear regression model that supports all the geometric and material parameters involved in predicting punching shear. Despite its simplicity, this formulation showed accuracy equivalent to that of the neuro-fuzzy model.

• Journal of Ginseng Research
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• 제34권4호
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• pp.274-281
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• 2010

This experiment was conducted to examine ginseng lines resistant and susceptible to high-temperature injury and to investigate characteristics of the selected lines: leaf burning phenomenon, chlorophyll content, quantum yield, and maximum light interception rate. The leaf burning phenomenon incidence rates of the resistant lines Yunpoong, high-temperature injury resistance (HTIR)1, HTIR2, and HTIR3 were low: 5.8%, 3.6%, 4.0%, and 1.9%, respectively. Resistance of the susceptible lines Chunpoong, high-temperature injury susceptible (HTIS)1, and HTIS2 was high: 58.5%, 23.2%, and 21.7%, respectively. The chlorophyll content (SPAD value) of the resistant lines Yunpoong, HTIR1, HTIR2, and HTIR3, which were exposed to high temperatures and intense light, remained as high at 24.8, 27.9, 24.9, and 30.6, respectively, but that of the susceptible lines Chunpoong, HTIS1, and HTIS2 was low at 21.0, 21.1, and 20.1, respectively. During the summer season, the quantum yield of the resistant lines (Yunpoong, HTIR1, HTIR2, and HTIR3) changed little, but that of the susceptible lines (Chunpoong, HTIS1, and HTIS2) changed dramatically. The maximum light interception rate (Fm/Fv value) for the resistant lines (Yunpoong, HTIR1, HTIR2, and HTIR3) was as high as 0.848, 0.794, 0.805, and 0.813, respectively, while that of the susceptible lines (Chunpoong, HTIS1, and HTIS2) was 0.678, 0.642, and 0.717, respectively. Based on these results, the high-temperature injury-resistant lines seemed to be less susceptible to high light, even at high temperatures. Future studies on red ginseng quality and its active ingredients in resistant ginseng lines and field experimentation will be conducted to verify the potential of the resistant lines.

• 전기학회논문지
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• 제56권9호
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• pp.1643-1647
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• 2007

Recently, there is a need for research concerning the technologies and precaution methods against electronic bomb assaults. There lays perplex constitution and much coupling phenomenon in this type of system, and thus requires much time and memory in order to translate the system with the existing translation methods. Applying the EMT (Electromagnetic Topology) would prove much more efficient. In this paper, EMT has been applied to the circuit-like micro system, previously employed in micro systems. Also, each section has been interpreted using the BLT (Baum, Liu, Tesche) equation using the EMT, then reconstructed, consequentially interpreting an entire system. In this paper, a simple circuit containing active and passive elements based on a CPW has been interpreted employing the BLT equation, and has been proven by experiment using the circuit simulation, a simulation officially recognized for its accuracy in interpreting small structures. The interpretation results have been presented by an S-parameter, and by comparing the interpretation results attained through the BLT equation and that from common simulation to that from experimentation, that the BLT equation turned out to be the most reliable interpretation method could be found.

• Structural Engineering and Mechanics
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• 제50권5호
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• pp.589-603
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• 2014

Expressions for determining the value of the impact force as reported in the literature and incorporated into code provisions are essentially quasi-static forces for emulating deflection. Quasi-static forces are not to be confused with contact force which is generated in the vicinity of the point of contact between the impactor and target, and contact force is responsible for damage featuring perforation and denting. The distinction between the two types of forces in the context of impact actions is not widely understood and few guidelines have been developed for their estimation. The value of the contact force can be many times higher than that of the quasi-static force and lasts for a matter of a few milli-seconds whereas the deflection of the target can evolve over a much longer time span. The stiffer the impactor the shorter the period of time to deliver the impulsive action onto the target and consequently the higher the peak value of the contact force. This phenomenon is not taken into account by any contemporary codified method of modelling impact actions which are mostly based on the considerations of momentum and energy principles. Computer software such as LS-DYNA has the capability of predicting contact force but the dynamic stiffness parameters of the impactor material which is required for input into the program has not been documented for debris materials. The alternative, direct, approach for an accurate evaluation of the damage potential of an impact scenario is by physical experimentation. However, it can be difficult to extrapolate observations from laboratory testings to behaviour in real scenarios when the underlying principles have not been established. Contact force is also difficult to measure. Thus, the amount of useful information that can be retrieved from isolated impact experiments to guide design and to quantify risk is very limited. In this paper, practical methods for estimating the amount of contact force that can be generated by the impact of a fallen debris object are introduced along with the governing principles. An experimental-calibration procedure forming part of the assessment procedure has also been verified.