• Journal of Engineering Education Research
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• v.23 no.3
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• pp.20-31
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• 2020

The purpose of this study is to suggest a meaningful way of implementing science and engineering integrated lessons in school science settings. To this end, two types of science and engineering integrated lesson units (focusing on the physic concepts of light and wave) were developed based on the core elements of science and engineering integrated lesson; object, context, engineering design, and connection with science. These two units were implemented in free semester program in a middle school in a metropolitan city. Throughout the process of program implementation, instructor's reflection and focus group interview with participant students were collected to reveal problems arising from the field implementation. In addition, engineering education experts were interviewed to discuss the potential problems and possible solutions for the problems. As results of the study, five main problems of implementing escience and engineering integrated lessons in a school science setting were revealed and practical solutions for the problems were suggested by the experts.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.181-186
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• 2000

The setup of the moir$\acute{e}$ deflectometry using the virtual grating was done, so the convergence and divergence of a pencil of ray was determined. The light source was He-Ne laser(3mW). The focal length of the first lens, the second lens being 18 mm, 250 mm respectively was used for the setup of the beam expander. The optics of the moir$\acute{e}$ deflectometry determining the vergence was used a diffraction grating(pitch = $1.6{\mu}m/line$) and a front flat reflection mirror. The effective focal length of the trial lens set was measured and compared with the theoretical value.

• Transactions on Electrical and Electronic Materials
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• v.9 no.3
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• pp.128-133
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• 2008

In this paper, in order to analyze property of frequency response in microphone using optical sensor, acousto-optic sensor system has been implemented. The capacitance microphone and fiber-optic transmission path type fiber-optic microphone (FOM) have weaknesses in directivity, size, weight, and price. However suggested optical microphone can be constituted by cheap devices, so it has many benefits like small size, light weight, high directivity, etc. Head part of optical microphone which is suggested in this paper is movable back and forth by sound pressure with the attached reflection plate. Operating point has also been determined by measuring the response characteristics. The choosing the point, which has maximum linearity and sensitivity has changing the distance between optical head and vibrating plate. We measured the output of the O/E transformed signal of the optical microphone while frequency of sound signal is changed using sound measurement /analysis program, "Smaart Live" and "USBPre", which are based on PC, and compared the result from an existing capacitance microphone. The measured optical microphone showed almost similar output characteristics as those of the compared condenser microphone, and its bandwidth performance was about 4 kHz at up to 3 dB.

• Current Optics and Photonics
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• v.3 no.5
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• pp.401-407
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• 2019

Polymeric optical waveguide devices with Bragg gratings have been investigated, for implementing tunable lasers and wavelength filters used in wavelength-division-multiplexed optical communication systems. Owing to the excellent thermo-optic effect of these polymers, wavelength tuning is possible over a wide range, which is difficult to achieve using other optical materials. In this study the phase-mask technology, which has advantages over the conventional interferometeric method, was introduced to facilitate the fabrication of Bragg gratings in polymeric optical waveguide devices. An optical setup capable of fabricating multiple Bragg gratings simultaneously on a 4-inch silicon wafer was constructed, using a 442-nm laser and phase mask. During fabrication, some of the diffracted light in the phase mask was totally reflected inside the mask, which affected the quality of the Bragg grating adversely, so experiments were conducted to solve this issue. To verify grating uniformity, two types of wavelength-filtering devices were fabricated using the phase-mask lithography, and their reflection and transmission spectra were measured. From the results, we confirmed that the phase-mask method provides good uniformity, and may be applied for mass production of polymer Bragg-grating waveguide devices.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.97-99
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• 2022

For the early identification and treatment of colorectal cancer, accurate polyp segmentation is crucial. However, polyp segmentation is a challenging task, and the majority of current approaches struggle with two issues. First, the position, size, and shape of each individual polyp varies greatly (intra-class inconsistency). Second, there is a significant degree of similarity between polyps and their surroundings under certain circumstances, such as motion blur and light reflection (inter-class indistinction). U-net, which is composed of convolutional neural networks as encoder and decoder, is considered as a standard for tackling this task. We propose an updated U-net architecture replacing the encoder part with vision transformer network for polyp segmentation. The proposed architecture performed better than the standard U-net architecture for the task of polyp segmentation.

• Journal of Science and Technology Studies
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• v.16 no.1
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• pp.5-22
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• 2016

MERS(Middle East Respiratory Syndrome), an acute and infectious viral disease with high fatality sneaked in South Korea in May 2016. Although MERS is officially declared to be exterminated in Korea by the date of December 24, it aroused a great panic throughout the country and remained many tasks requiring sincere deliberations and innovative actions. This study starts to summarize all that had been happening during first 7 months since last May, reconsider the whole process in light of disaster paradigm, analyze the causes and tasks of such turmoil under the framework of social medicine. It is wrapped up with the visions and prospect of the social medicine, an interdisciplinary approach that takes into account the expert knowledge of academia, administrative knowledge of government, media knowledge from traditional/new media and lay knowledge of civil society.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.5
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• pp.273-283
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• 2013

The traditional medical equipments are devices used by medical professionals but not used in public environment. Common people, however, require light-weight medical devices to make healthcare for themselves nowadays. Those medical devices are used to monitor personal health status such as blood pulse, blood pressure, diabetes. Also, some of them are operated in mobile environment called u-healthcare. This paper implements a portable healthcare system composed of $SpO_2$(Saturation of Partial Pressure Oxygen) sensors and a gateway for detecting hypoxemia during people's leasure activity such as climbing or hiking. The $SpO_2$ sensor is designed as watch style to support dynamic exercise and the gateway is designed as necklace style to support the elderly. The result of a performance evaluation shows that the performance of the $SpO_2$ sensor using reflection technology is not lower than that of a clairvoyant styled $SpO_2$ sensor.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.513-520
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• 2000

An integrated grader which measures soluble solid content, color and weight of fresh apples was developed by NAMRI. The prototype grader consists of the near infrared spectroscopy and machine vision system. Image processing system and an algorithm to evaluate color were developed to speed up the color evaluation of apples. To avoid the light glare and specular reflection, an half-spherical illumination chamber was designed and fabricated to detect the color images of spherical-shaped apples more precisely. A color revision model based on neural network was developed. Near-infrared(NIR) spectroscopy system using NIR reflectance method developed by Lee et al(1998) of NAMRI was used to evaluate soluble solid content. In order to observe the performance of the grader, tests were conducted on conditions that there are 3 classes in weight sorting, 4 classes in combination of color and soluble solid content, and thus 12 classes in combined sorting. The average accuracy in weight, color and soluble solid content is more than about 90 % with the capacity of 3 fruits per second.

• International Journal of High-Rise Buildings
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• v.13 no.1
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• pp.33-56
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• 2024

This paper examines China's rapid shift from low-rise to high-rise urban development, focusing on Shanghai as a case study. It provides a detailed analysis of the rapid vertical developments over the past five decades, highlighting gradual and sudden tall building changes. The study also surveys tall building development in the ten "tallest cities" across China, including Hong Kong, Shenzhen, Guangzhou, Shanghai, Wuhan, Chongqing, Chengdu, Shenyang, Hangzhou, and Nanning, while listing the tallest ten buildings in each city. The focus is on the drivers behind these towering structures: globalization, an economic powerhouse, and finance center, urbanization and population density, architectural innovation and ambition, competition and prestige, land availability and utilization, government support and planning, and tourism. The paper critically examines the sustainability of this trend in light of new Chinese policies restricting the construction of high-rise buildings exceeding 500m and 250m in smaller cities due to safety and security concerns. This prompts a reflection on the long-term viability and implications of the predominantly high-rise trajectory in urban development.

• Journal of Ocean Engineering and Technology
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• v.27 no.3
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• pp.22-28
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• 2013

This paper suggests a navigation information display system that is based on augmented reality technology. A navigator always has to confirm the information from marine electronic navigation devices and then compare it with the view of targets outside the windows. This "head down" posture causes discomfort and sometimes near accidents such as collisions or missing objects, because he or she cannot keep an eye on the front view of the windows. Augmented reality can display both virtual and real information in a single display. Therefore, we attempted to adapt AR technology to assist navigators. To analyze the outside view of the bridge window, various computer image processing techniques are required because the sea surface has many noises that disturb computer image processing for object detection, such as waves, wakes, light reflection, and so on. In this study, we investigated an analysis module to extract navigational information from images that are captured by a CCTV camera, and we validated our prototype.