• 한국산업융합학회 논문집
• /
• 제26권5호
• /
• pp.907-913
• /
• 2023

Currently, the sprinkler method is widely used as an initial suppression method in existing firefighting systems. However, this method can cause significant damage to both equipment and facilities in the hydration area. To minimize this damage, fire extinguishing monitors are being developed that can spray fire extinguishing water directly at the point of fire. These monitors are installed on the top floor of the ship, such as the Living Quarter and Ventilation System. While conventional fire extinguishing monitors focus on lightweight research with a short spray port and require a spray distance of about 40 to 45m, recent developments necessitate a longer spray port, similar to a water cannon, requiring a spray distance of about 70 to 75m. This study aims to predict the injection distance of both the existing ship-installed fire extinguisher and the long spray port fire extinguisher through hydrodynamic computer analysis, and to determine whether the injection distance has increased.

• 한국인터넷방송통신학회논문지
• /
• 제24권2호
• /
• pp.35-40
• /
• 2024

본 논문은 이전 연구에서 구현된 OnePIC 앱의 실행 성능과 저장 성능을 분석하여 OnePIC 앱의 실용성을 검증한다. OnePIC 앱은 다양한 초점을 가진 사진들을 촬영한 후, 원하는 초점의 사진을 얻을 수 있는 카메라 앱이다. 본 논문은 성능평가를 위해 거리별 다초점 촬영 시간과 객체별 다초점 촬영 시간을 세부적으로 분석하였다. 성능평가는 실제 스마트폰에서 실측하는 방식으로 진행되었다. 거리별 다초점 촬영 시간은 5장에 0.84초, 객체 감지 시간은 객체 개수와 관계없이 0.19초, 객체별 다초점 촬영 시간은 5장에 4.84초 정도로 측정되었다. 다초점 사진을 한 장에 저장한 All-in-JPEG 파일 크기와 각각 JPEG 파일로 저장한 경우를 비교한 결과, All-in-JPEG 파일 크기가 미묘하게 줄어 저장공간의 큰 이득은 없었다. 그렇지만 All-in-JPEG은 다초점 촬영된 사진들의 관리 면에서 매우 용이하다. 결론적으로 본 논문의 성능평가 결과, OnePIC 앱은 촬영 시간과 사진의 저장 크기 및 관리 면에서 실용적인 것으로 판단된다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.53.2-53
• /
• 2001

The Non-Contact Optical Sensor using the Hologram Laser for CD Pickup was developed to measure a shape of transparent objects and shown a good performance. Therefore the problems caused by the contact sensor are solved by using the Non-Contact Sensor. The Non-Contact Sensor has to move toward the objects and obtain the Focus Error Signal to measure a position of transparent objects. However, if the distance between the sensor and the object is shorter than the working distance of the objective lens, the sensor will be collided against the objects. In this paper we proposed a new algorithm to estimate the start position of the Focus Error Signal to solve the problems of collision between the sensor and the objects. In addition, we verified that the algorithm is free from the collision in the real time measurement.

• 전자공학회논문지B
• /
• 제32B권6호
• /
• pp.886-898
• /
• 1995

One of the ways to measure the distance in the computer vision is to use the focus and defocus. There are two methods in this way. The first method is caculating the distance from the focused images in a point (MMDFP: the method measuring the distance to the focal plane). The second method is to measure the distance from the difference of the camera parameters, in other words, the apertures of the focal planes, of two images with having the different parameters (MMDCI: the method to measure the distance by comparing two images). The problem of the existing methods in MMDFP is to decide the thresholding vaue on detecting the most optimally focused object in the defocused image. In this case, it could be solved by comparing only the error energy in 3x3 window between two images. In MMDCI, the difficulty is the influence of the deflection effect. Therefor, to minimize its influence, we utilize two differently focused images instead of different aperture images in this paper. At the first, the amount of defocusing between two images is measured through the introduction of regularization and then the distance from the camera to the objects is caculated by the new equation measuring the distance. In the results of simulation, we see the fact to be able to measure the distance from two differently defocused images, and for our approach to be robuster than the method using the different aperture in the noisy image.

• 대한방사선기술학회지:방사선기술과학
• /
• 제41권5호
• /
• pp.391-396
• /
• 2018

The purpose of this study was to compare and analyze the patient dose according to the distance between the X-ray tube focus and the image receptor, and to propose a new method for quantitatively evaluating the image quality. Using this quantitative evaluation method, the optimal distance for increasing x-ray image quality with low radiation dose was estimated between source and image receptor in Rib series radiography. Phantom images were obtained by changing the distance between focus and image receptor (100 cm and 180 cm). The patient radiation dose was estimated using entrance surface dose and dose area product. In order to evaluate image quality objectively, a non - reference image evaluation method was employed with paper and salt noise and Gaussian filter. As a result of this study, when the SID was changed from 100 cm to 180 cm, the entrance surface dose decreased by 4 ~ 5 times and the dose area product decreased by 3 times. In addition, there is no significant difference in image quality between of SID 180 cm and SID 100 cm. In conclusion, it was demonstrated that performing the rib series radiography at SID 180 cm is an optimal method to reduce the exposure dose and improve the image quality.

• Earthquakes and Structures
• /
• 제18권5호
• /
• pp.543-553
• /
• 2020

Past earthquakes experience shows that serious damage or collapse of buildings have dramatically accrued when sufficient separation distance has not been provided between two adjacent structures. The majority of past studies related to the pounding topic indicate that obtaining the gap size between two buildings is able to prevent collision and impact hazards during seismic excitations. Considering minimization of building collisions, some relationships have been suggested to determine the separation distance between adjacent buildings. Commonly, peak lateral displacement, fundamental period and natural damping as well as structural height of two adjacent buildings are numerically considered to determine the critical distance. Hence, the aim of present study is to focus on all mentioned parameters and also utilizing the main characteristic of earthquake record i.e. PGA to examine the lateral displacement of irregular structures close to each other and also estimate the sufficient separation distance between them. Increasing and decreasing the separation distance is inherently caused economical problems due to the land ownership from a legal perspective and pounding hazard as well. Therefore, a new equation is proposed to determine the optimum critical distance. The accuracy of the proposed formula is validated by different models and various earthquake records.

• 한국식생활문화학회지
• /
• 제26권3호
• /
• pp.249-260
• /
• 2011

The current research aims to verify whether distance learning can be adopted in practical cooking class for Korean foods in a two-year college. The distance learning education can be a supplementary method to the traditional cooking class. The face-to-face teaching method and the distance learning method were compared in order to determine which of the one is more effective teaching method in the practical cooking class. The results of the present experimental study were analyzed based on the participant's learning expectation and satisfaction, the evaluation of the experimental process, and the academic performance. The results of this study showed that the participants in the face-to-face class evaluated their class experience higher than those in the distance learning class with respect to the participant's learning expectation and satisfaction, and the evaluation of the experimental process. On the contrary, regarding the academic performance, the participants in the distance learning class showed higher scores than those in the face-to-face class. The end result supports the claim that the distance learning method is more effective in the participants for gaining cooking knowledge.

• 대한물리치료과학회지
• /
• 제13권3호
• /
• pp.77-84
• /
• 2006

The purpose of this study is to introduce the effect of attentional focus on performance of task. Previous studies has shown that motor learning can be enhanced by directing performers's attention to the effects of their movements(external focus), rather than to the body movement producing the effects(internal focus). Wulf and colleagues have invoked the 'constrained action hypothesis' to explain the comparative benefits of adopting an external rather than an internal focus of attention. This hypothesis proposed that when performers utilize an internal focus of attention, they may actually constrain or interfere with automatic control processes that would normally regulate the movement, whereas an external focus of attention allows the motor system to more naturally self-organize. Electromyography(EMG) was used to determine neuromuscular correlates of external versus internal focus differences. EMG activity was lower with an external relative to an internal focus. This suggest that an external focus of attention enhances movement economy, and presumably reduces 'noise' in the motor system that hampers fine movement control. Focusing on a more remote effect seems to facilitate the discriminability of the effect from the body movements that produced it and to be more beneficial than focusing on a very close effects. There might be an optimal distance of the effect, at which ti wis easily distinguishable from the body movement but at which it is also still possible for the performer to relate this effect to the movement techniques. Future Studies of motor learning of patient need to accommodate these new finding and account for the role of the learner's attentional focus and its influencing on learning.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2000년도 춘계학술대회 논문집
• /
• pp.32-42
• /
• 2000

In this paper, we outlines the basic pricing rules that developed over the years, and illustrates how these rules apply in practice using railway fare, price discrimination in railway travel. we review the problems of rail fare system reflecting the market fare decision and consider fare decision structure and relative fare comparison with other modes of transportation. Specifically, we focus on tile effect of tile “fare varying system with distance”, using the characteristics of long distance transportation modes. And set up the framework for reasonable fare decision under the current circumstances.

• International Journal of Advanced Culture Technology
• /
• 제8권3호
• /
• pp.260-268
• /
• 2020

Currently, it is usually a 3D scanner processing method as a laser method. However, the laser method has a disadvantage of slow scanning speed and poor precision. Although optical scanners are used as a method to compensate for these shortcomings, optical scanners are closely related to the distance and precision of the object, and have the disadvantage of being expensive. In this paper, 3D scanner using variable focus lens-based structured light module with improved measurement precision was designed to be high performance, low price, and usable in industrial fields. To this end, designed a telecentric optical system based on a variable focus lens and connected to the telecentric mechanism of the step motor and lens to adjust the focus of the variable lens. Designed a connection structure with optimized scalability of hardware circuits that configures a stepper motor to form a system with a built-in processor. In addition, by applying an algorithm that can simultaneously acquire high-resolution texture image and depth information and apply image synthesis technology and GPU-based high-speed structured light processing technology, it is also stable for changes to external light. We will designed and implemented for further improving high measurement precision.