• Design & Manufacturing
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• v.17 no.2
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• pp.9-14
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• 2023

In this study, an experiment was conducted to confirm the applicability of the external shape control of the ultrasonic knife to the CFRTP material, which is the base material of thermoplastic. TC910 based on polyamide6 (PA6) was used as the material. The slope 와 and tool transfer speed of the material and tool were selected as process factors for processing, and the following results were obtained. Under all cutting conditions using an ultrasonic knife, friction heat caused by high-frequency vibration was issued at 150℃ at the contact part between the material and the knife during cutting. As a result of the cutting force analysis, the faster the transfer speed, the higher the cutting force as the angle of entry of the blade increased, and the size of the cutting force changed during cutting. As for the size of the burr in accordance with the transfer speed condition, the smallest burr occurred at 150mm/min in the side part, and the smallest burr occurred at 150mm/min and 200mm/min in the case of the outlet burr. The size of the burr according to the entry angle tended to decrease as the tool entry angle increased, and the side part tended to increase as the tool entry angle increased. As a result of the cutting surface analysis, it was confirmed that the base material was eluted under all conditions, and the faster the transfer speed, the lower the elution phenomenon of the base material. Based on the above results, cutting the CFRTP material with an ultrasonic knife is possible, but the effect on heat generation caused by friction needs to be minimized, and further research needs to be conducted on this.

• Progress in Medical Physics
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• v.33 no.4
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• pp.164-171
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• 2022

The number of facilities using radiation generators increases and related regulations are strengthened, the establishment of a shielding management and evaluation technology has become important. The characteristics of the radiation generator used in previous report differ from those of currently available high-frequency radiation generators. This study aimed to manufacture lead, iron, and concrete shielding materials for the re-verification of half-value layers, tenth-value layers, and attenuation curve. For a comparison of attenuation ratio, iron, lead, and concrete shields were manufactured in this study. The initial dose was measured without shielding materials, and doses measured under different types and thicknesses of shielding material were compared with the initial dose to calculate the transmission rate on 50-300 kVp X-ray. All the three shielding materials showed a tendency to require greater shielding thickness for higher energy. The attenuation graph showed an exponential shape as the thickness decreased and a straight line as the thickness increased. The difference between the measurement results and the previous study, except in extrapolated parts, may be due to the differences in the radiation generation characteristics between the generators used in the two studies. The attenuated graph measured in this study better reflects the characteristics of current radiation generators, which would be more effective for shield designing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.91-92
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• 2023

With the development of technology, interest in the implementation of free-form buildings is increasing, and research on producing free-form panels is being conducted accordingly. Since free-form buildings are curved and consist of geometric shapes, there are many problems with the production technology of free-form panels that implement them. Due to the inability to reuse molds, the cost of disposal of construction waste and waste of manpower for assembly increase the construction period and construction cost. To improve these limitations, a 3D printed concrete nozzle for FCP production was developed. However, this technology is not quantitatively extruded according to the shape of the panel, and there is a problem that residues are generated. Therefore, an free-form panel extrusion experiment was conducted to analyze the limitations of existing nozzles and to analyze the requirements for the development of new concrete extrusion nozzles. Existing nozzles were unable to be quantitatively extruded, resulting in errors. Due to the weak pressure of the screw and the inability to adjust the internal pressure, detailed extrusion speed control was impossible, and residue generation in the opening and closing device seemed to be the cause. Therefore, a pump capable of quantitative concrete pressure transfer and a pressure control device for easy extrusion of concrete are required. In addition, it is judged that it is necessary to develop an opening and closing device and an extrusion device that do not generate residues. The results of this study are expected to provide information for FCP production and production and to be a basic study of technologies necessary for the production of free-form building panels.

• The Journal of the Acoustical Society of Korea
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• v.43 no.2
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• pp.168-177
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• 2024

When designing an underwater Piezoelectric Energy Harvester (PEH), Vortex Induced Vibration (VIV) is generated throughout the cantilever through a change in curvature, and the generation of VIV increases the vibration displacement of the curved cantilever PEH, which is an important factor in increasing actual power. The material of the curved PEH selected a Polyvinyline Di-Floride (PVDF) piezoelectric film, and the flow velocity is set at 0.1 m/s to 0.50 m/s for 50 mm, 130 mm, and 210 mm with various curvatures. The strain energy change of PEH by VIV was observed. The smaller the radius of curvature, the larger the VIV, and as the flow rate increased, more VIV appeared. Rapid shape transformation due to the small curvature was effective in generating VIV, and strain energy, normalized voltage, average power, etc. To increase the amount of power of the PEH, it is considered that the average power will increase as the number of curved PEHs increases as well as the steep curvature is improved.

• Fashion & Textile Research Journal
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• v.26 no.1
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• pp.99-109
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• 2024

This study aimed to assess the satisfaction levels of adolescents with beauty programs, investigate the factors influencing them, and present foundational insights for designing cosmetics and beauty education initiatives tailored to adolescents. Specifically focusing on the "Safety and Use Education for Youth Cosmetics" program implemented in Gwangju Metropolitan City, it examined the satisfaction of participants, including students, instructors, and school teachers involved in the education. The study was based on action research, a qualitative methodology. The conclusions are as follows: First, participants gained knowledge and information encompassing various aspects of cosmetics, such as types, expiration dates and usage span, face wash and skin types, shampooing methods, scalp care, role and significance of sunscreen, skin trouble management, and identification of skin type, through cosmetic education programs. Second, participants learned about techniques such as eyebrow trimming, eyebrow shape correction, facial contour correction, skin blush supplementation, color makeup, personal color, and tattooing. Third, there is an urgent need to develop different educational teaching resources suitable for implementation across elementary, middle, and high schools. Fourth, it is necessary to cultivate higher-quality instructors in this digital age. Fifth, it is crucial to explore new methods of delivering beauty education to adolescents. We hope the insights gleaned from this study will serve as useful foundational data, albeit modest, fostering new beauty trends amidst the challenging landscape of youth education.

• Korean Journal of Heritage: History & Science
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• v.51 no.1
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• pp.48-65
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• 2018

The authors of this paper aim to make a record of the construction process, its symbolic meaning, and the changes in the status of the landscape plants at the Pasanseodang according to the Report on the Pasanseodang written by Park Gyu-hyun in 1874. First, the construction of Samgahun Pavilion, which is located in Myo-ri, Habin-myun, Dalsung-gun, Daegu, took about 90 years and spanned the lifetimes of Park Sungsoo, an 11th-generation descendant of Park Paengnyun (1417~1456) through to Park Kyuhyun, a 14th-generation descendant. It was called the shape of dragon, with its head facing the tail (回龍顧尾形), in feng shui. Second, the village of Pahwoe was founded in 1769, the 45th year of the reign of King Yeongjo, by Park Sungsoo for the purpose of socializing with his friends at his thatched home, and was named after his own courtesy name (Samgahun). Park Kwangseok, the second son of Park Sungsoo, built the sarangchae in 1826 and the anchae in 1869 after his marriage (in 1783). Then, Park Kyuhyun, the grandson of Park Kwangseok, built the pond and planted it with lotus flowers, and built the Hayeopjeong in 1874. The Pasanseodang, as the precursor of the Hayeopjeong, may be related with the name of the hillside region behind Samgahun. Third, a quadrangular-shaped pond with a length of 21m and a width of 15m was also built and planted with lotus flowers. In the center of the pond is a small round island that reflects the world view of the Chosun dynasty, i.e. that the sky is round and the landmass is quadrangular. Meanwhile, the name of the Hayeopjeon reflects the value system of aristocrats who lived a life of leisure and artistic indulgence. They called the eastern room "Yeeyeonhun" (怡燕軒) and the western room "Mongyangjae" (蒙養齋), names which embody their wishes for a good life as a member of the nobility and a bright future for one's descendants. Fourth, in Confucian terms, the authors infer the points of view reflected in the kinds of trees that were planted according to Confucian norms (pine tree, lotus, bamboo), the living philosophy of sustainability (willow), the ideology of seclusion and the search for peace of mind (bamboo), and relief efforts for the poor and a life of practicality (chestnut, oak, wild walnut, lacquer). The authors assert that this way of planting trees was a highly effective design feature of landscape architecture that drew on the locational and symbolic significance of the Seodang. Fifth, the majority of the trees that were initially planted withered and were replaced with different species, except for the locust and lotus, at this point. Nevertheless, a review of the process of construction, symbolic meaning, and original architectural landscape of the Samgahun is of value in demonstrating the extended symbolic meaning of their descendants in terms of the practical loss of the function of the Seodang, the values of Feng Sui (red in the east, white in the west, based on the principles of Feng Sui), the function of repelling evils spirits (kalopanax, trifoliate orange), aesthetic and practical values (sweetbrier, apricot, pear, peach, and oriental oak trees), and the prosperity of the family and the timeless value of honest poverty (silk, crape myrtle, and yew trees).

• Research in Community and Public Health Nursing
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• v.14 no.2
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• pp.263-273
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• 2003

Objectives: The purpose of this study was to identify the family phenomenon and characteristics by ICNP such as family shape, life standard. area, and development stage. Method: 1. Sample size was 115. 2. Data analysis method included frequency analysis including ratio. Results: 1. On the distribution of the family phenomena by family shape, the nuclear family showed a higher ratio on the distribution in family communication and the unhealthy life style. The nuclear family was related to children andhad a higher ratio on the inadequate care management of the sick member. The extended family showed the highest ratio on the inadequate care management of sick member. 2. On the distribution of the family phenomena by family life standard, the family with medium life standard showed a higher ratio on the inappropriate family coping, whereas the family with lower life standard appeared to have a higher ratio on the inadequate care management of the sick member. 3. On the distribution of the family phenomena by area. the large city area showed the highest ratio on the inappropriate family coping, the medium and small city area appeared to have the highest ratio on the unhealthy life style. The county area showed the highest ratio on the inadequate care management of sick member. 4. On the distribution of the family phenomena by development stage, the family in rearing period showed a higher ratio on the inappropriate family coping and the lack of family intimacy. Families with preschool children showed a higher ratio on the unhealthy life style, and families with school age children showed the highest ratio on the inappropriate family coping. Families with adolescents appeared to have the highest ratio on the disturbance in family communication, and families with launching young adults showed the highest ratio on the inadequate care management of sick member. 5. On the distribution of the family characteristics by family shape, the nuclear family showed a higher ratio on the family characteristics such as less communication chances among family members and neglect of general child rearing, whereas the third generation family appeared to have a higher ratio on the characteristics such as overburden of housewife's role and short of caring among family members. 6. On the distribution of the family characteristics by family life standard, the family of medium life standard showed higher ratio on the family characteristics such as a few communication chance among family and overburden of housewife's role, and the family of lower life standard appeared to higher ratio on the family characteristics such as short of caring among family members. 7. On the distribution of the family characteristics by area. the large city area showed a higher ratio on the family characteristics such as overburden of housewife's role and neglect of general child rearing. The medium and small city area appeared to have a higher ratio on the family characteristics such as less communication chancec among family members. The county area showed a higher ratio on the family characteristics such as short-term care among family members. 8. On the distribution of the family characteristics by development stage, the family with rearing period showed a higher ratio on the family characteristics such as neglect of general child rearing. Families with preschool children showed a higher ratio on the family characteristics such as less communication chancec among family members. Families with school age children showed a higher ratio on the family characteristics such as overburden of housewife's role. Families with adolescents appeared to have a higher ratio on the family characteristics such as less communication chances among family members. Families with launching young adults showed a higher ratio on the family characteristics such as less communication chances and short-term care among family members.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_2
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• pp.645-651
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• 2007

In general, contours in digital vector maps, which represent terrain characteristics and shape, are created by 3D digitizing the same height points using aerial photographs on the analytical or digital plotters with stereoscopic viewing. Hence, it requires lots of task, and subjective decision and experience of the operators. DTMs are generated indirectly by using contours since the national digital maps do not include digital terrain model (DTM) data. In this study, model key points which depict the important information about terrain characteristics were extracted from the contours. Further, determination of the efficient and flexible grid sizes were proposed to generate optimal DTM in terms of both quantitative and qualitative aspects. For this purpose, a progressive sampling technique was implemented, i.e., the smaller grid sizes are assigned for the mountainous areas where have large relief while the larger grid sizes are assigned for the relatively flat areas. In consequence, DTMs with multi-grid for difference areas could be generated instead of DTMs with a fixed grid size. The multi-grid DTMs reduce computations for data processing and provide fast display.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.3
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• pp.139-146
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• 2004

A 2D/3D complex optical system and its vision inspection algerian is proposed and implemented as a single probe system for high speed, precise vision inspection of the solder pastes. One pass un length labeling algorithm is proposed instead of the conventional two pass labeling algorithm for fast extraction of the 2D shape of the solder paste image from the recent line-scan camera as well as the conventional area-scan camera, and the optical probe path generation is also proposed for the efficient 2D/3D inspection. The Moire interferometry-based phase shift algerian and its optical system implementation is introduced, instead of the conventional laser slit-beam method, for the high precision 3D vision inspection. All of the time-critical algorithms are MMX SIMD parallel-coded for further speedup. The proposed system is implemented for simultaneous 2D/3D inspection of 10mm${\times}$10mm FOV with resolutions of 10 ${\mu}{\textrm}{m}$ for both x, y axis and 1 ${\mu}{\textrm}{m}$ for z axis. Experiments conducted on several nBs show that the 2D/3D inspection of an FOV, excluding an image capturing, results in high speed of about 0.011sec/0.01sec, respectively, after image capturing, with $\pm$1${\mu}{\textrm}{m}$ height accuracy.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.152-162
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• 2017

A hydrophilic coating solution was prepared by adding a silane coupling agent and a nano-inorganic oxide in aqueous surfactant solution to increase the efficiency of photovoltaic power generation due to the introduction of antifogging and antifouling properties on the glass surface of the solar cell module. Addition of $Ludox^{(R)}$, a nano-inorganic oxide, to 1% hydrophilic coating solution showed improved hydrophilicity and excellent antifogging effect regardless of $Ludox^{(R)}$ concentration. However, the antifouling effect on the glass surface was showed only when Ludox was added more than 10%. In the case of addition of 0.7% of hydrolyzed TEOS at pH 4, the antifogging effect was maintained as a result of the steam test as well as the antifouling effect even after the coated glass surface was rubbed 100 times with a wet Kimwipe. In addition, from the surface roughness ($R_q$) calculated using AFM data, the higher surface roughness with irregular surface shape was obtained with the higher concentration of TEOS. The addition of 0.7% of TEOS showed relatively high surface roughness and well organized surface condition which can help to improve transmittance of light. In conclusion, $Ludox^{(R)}$ is not required only for the antifogging property. However, at least 10% of Ludox should be added to show antifouling effect and 0.7% of TEOS should be added for good durability.