• Korean Journal of Optics and Photonics
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• v.34 no.4
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• pp.157-169
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• 2023

Augmented reality (AR) using a head mounted display (HMD) is used in various fields such as military, medicine, manufacturing, gaming, and education. In this paper, we discuss the design and fabrication of the AR optical system, which is most essential for HMD. The AR optical system for HMD requires a wide transparent area in which the augmented image of the display and the real world can be viewed at the same time. To this end, an AR optical system was designed and manufactured by dividing it into three parts according to each characteristic. Also, the refractive index of the ultra-violet (UV) adhesive layer required to make the three optical systems into one complete AR optical system was considered from the design stage to minimize the optical path shift phenomenon when the input light source passes through the UV adhesive layer. In addition, when designing the AR optical system, two aspheric surfaces were used to compensate for off-axis aberration and to be suitable for mass production. Finally, for HMD mass production, an aspheric AR optical system with a thickness of 11 mm, a diagonal field of view of 40°, and a weight of 11.3 g was designed and manufactured.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.50-50
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• 2022

한국농어촌공사 산하의 농업용저수지 중 3786개소에 대한 수질조사를 '19년도에 실시한 결과, TOC 기준 4등급 초과 저수지 비율은 약 20%로써, 도심 근교 저수지에서 녹조현상 빈발로 인해 수질, 악취, 미관 등의 환경문제 개선 민원이 다수 발생하고 있다. 현재 녹조 발생 사후관리를 위해 주로 사용되고 있는 대형 조류제거선은 저수심 수변부에서의 적용성에 한계가 있고, Al 기반의 응집제를 사용하여 조류를 수거해서 폐기하고 있는 실정이다. (주)이엔이티는 농어촌연구원, (주)코레드, (주)삼호인넷과 함께 호소나 정체하천의 수변지역에 적용될 수 있는 저에너지형 유해조류 포집시스템 개발과, 수거된 조류부산물을 무독화하여 농업재료로 재활용하는 방안을 연구하고 있다. 저수지나 정체수역의 녹조는 바람, 수면유동 등에 의해 수변에 집적되는 특성이 있어, 인공지능 기술로 녹조현상을 감시하여 조류 밀집구간에 접근할 수 있는 자율이동식 수상이동장치를 개발 중이다. 수상이동장치는 조류포집장치를 탑재하기 위한 부력체, 원격 운전이 가능한 무인항법장치, 수변식생대 및 저수심지역 이동을 고려한 수차방식 추진체, 전체 장치의 전원 공급을 위한 고성능 배터리 등으로 구성하여 상세 도면 설계를 진행하고 있다. 조류포집장치에는 표층에 주로 분포하는 남조류를 선택 흡입하는 포집 부표를 적용하였고, Al계 응집제 사용을 배제한 분리막 실험을 통해 침지형 막분리조 및 가압형 농축조를 설계하였다. 유해조류 포집 및 농축은 수상에서 이동체에 탑재하여 이뤄지고, 육상에서는 자원 회수가 가능하도록 회분식 응집공정으로 구분하였다. 조류 밀집지역에서 수거된 조류의 무독화 및 농업재료 자원화 타당성 평가를 위해 특용 버섯균주를 활용한 시료별 분석항목을 선정하고 실험 매트릭스에 따라 실증실험을 수행하였다. 수거조류를 전처리하여 성분 및 발열량을 분석하고 버섯재배 전후의 마이크로시스틴 독소(LR, RR, LR)를 포함한 성분 분석을 수행하여, 고체연료, 비료 및 사료로 활용방안을 검토하였다. 무인자율이동 조류포집장치는 실증화 규모로 제작하여 기선정된 테스트베드에서 현장적용성 평가를 수행할 예정이다. 본 연구를 통해 개발된 유해조류 포집 시스템은 기존의 녹조제거 방안을 보완하여 정체수역의 생태계 복원 및 친수공간의 환경개선 등에 적용되며, 무독화가 입증된 유해조류의 농업재료 자원화 기술은 고부가 상품 개발 및 환경폐기물 감축에 활용될 것이다.

• Journal of TMJ Balancing Medicine
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• v.13 no.1
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• pp.21-26
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• 2023

Objectives: The purpose of this study is to report the effect of Korean medical treatment with Temporomandibular Joint Balancing Therapy (TBT) on Tic disorder patient who often glancing up when feels nerves, frightened or tired. Methods: In this study, Tic disorder patient was treated to △△ Korean medicine Hospital from June 12nd, 2022 to July 26th, 2023 by outpatient way. During the clinic period, the patient was treated by Korean medical treatment (acupuncture, cupping, herb medicine), especially using TBT. YGTSS (Yale Global Tic Severity Scale), NDI (Neck Disability Index) and VAS were used for measuring the Tic disorder and neck pain. Results: After treatment for 46 days, the YGTSS showed a decrease from 17 to 3, the VAS associated with Tic disorder also decreased from 6 to 1 and NDI associated with neck pain decreased from 7 to 4. Conclusions: These results showed that Korean medical treatment especially using TBT may have an effect on reducing symptoms of Tic disorder and neck pain. But the further researches are needed.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.1
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• pp.64-71
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• 2024

The most critical aspect of full-arch prosthodontic treatment is evaluating whether the patient's vertical occlusal dimension is appropriate, and if necessary, restoring it through increasing vertical dimension. If the vertical occlusal dimension is too low, it can lead to reduced chewing efficiency, as well as not only aesthetic concerns but also potential issues like hyperactivity of muscles and posterior displacement of the mandible. This report is about the patient dissatisfied with pronunciation and aesthetics due to an inappropriate vertical occlusal dimension resulting from prior prosthetic interventions, underwent full-arch prosthodontic restoration treatment. Through the utilization of digital diagnostic apparatus, a comprehensive evaluation was undertaken for patient's vertical occlusal dimension, occlusal plane orientation, and the condition of prosthetic restorations. Through 3D facial scanning, the facial landmarks were discerned, and subsequently, the new occlusal plane was established. This provided the foundation for a digitally guided diagnostic wax-up. An elevation of 5 mm from the incisor was determined. Comprehensive dental rehabilitation was then executed for all remaining teeth, excluding the maxillary four incisors. The treatment protocol followed a systematic approach by initially creating implant-supported restorations on both sides of the dental arch to establish a stable occlusal contact. Subsequently, prosthetic restorations for the natural dentition were generated. Diagnostic and treatment planning were established through the utilization of facial scanning. This subsequently led to a reduction in treatment complexity and an expedited treatment timeline.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.1
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• pp.8-15
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• 2024

The CaF₂ single crystal has notable characteristics such as a large band gap (12 eV), excellent transparency over a wide wavelength range, low refractive index and dispersion. Due to these outstanding properties, CaF₂ single crystal has considered as a promising material for short-wavelength light sources in recent lithography processes. However, there is an inherent birefringence of the material at 157 nm and the resulting aberration can be compensated for through the combination of the (100) plane and the (111) plane. Therefore, it is necessary to investigate the characteristics according to the plane. In this study, we analyzed crystallinity, optical properties of commercial CaF₂ single crystal wafers grown by the Czochralski method. In particular, through chemical etching under various conditions, it was confirmed that the shape of etch pits appears differently depending on the plane and the shape and array of specific etch pits affected by dislocations and defects were examined.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.119-120
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• 2003

우리나라에 분포하는 모자반류는 모두 28종으로 알려져 있으며 (이와 강 2002) 이 가운데 식용으로 이용되는 것은 모자반 (S. fulvellum)이 대표적이다. 모자반의 양식은 주로 서남해 지역에서 이루어지고 있으며 이들의 종묘생산은 자연에서 생식기탁이 성숙되는 4-5월경에 이루어지는데, 유배의 대량 방출을 위한 성숙 모조의 다량 확보가 어렵고 일시에 유배의 대량 방출을 유도하기 위한 성숙 유도 기법의 연구는 전무한 실정이다. 따라서 이 연구에서는 모조의 실내 배양을 통하여 유배의 대량 방출을 위한 성숙 유도 기법과 배양 조건별 엽체의 성숙 및 난방출율을 구하여 모자반의 조기채묘에 유용한 자료로 사용하고자 하였다. 또한 채묘된 발아체의 초기생장에 필요한 최적 배양 환경을 구명하고자 하였다. 모자반 모조는 전남 진도군 조도 지역의 수심 3-5m에서 채집하였으며, 채집 즉시 실험실로 운반하여 유수식 사육 수조에 수용하였다. 성숙 유도는 20$\ell$ 플라스틱 bottle을 사용하였으며, 성숙률의 정량화를 위하여 암생식기탁을 절단하여 수차례 멸균해수에서 세척후 멸균된 5cm직경의 petri dish에 멸균해수20$m\ell$와 함께 수용하여 Multi-chamber incubator에서 배양하였다. 배양조건은 5개 온도조건 (5, 10, 15, 20, $25^{\circ}C$)과16:8h의 장일 광주기 조건으로하였으며 조도는 80 $\mu$molm$^{-2}$ s$^{-1}$로 하였다. 모든 실험구는 3반복 실험하였으며 2일 간격으로 생식기탁의 생장 및 성숙 그리고 난방출 여부를 현미경하에서 측정하였다. 난이 방출된 모조로부터 유배를 분리하여 3개 조도 구간 (30, 60, 100 $\mu$molm$^{-2}$ s$^{-1}$)과 5개 온도 구간 (5, 10, 15, 20, $25^{\circ}C$)의 조합인 15개 배양 조건하에서 엽체의 길이생장을 측정하였다. 생식기탁으로부터 난의 방출은 15$^{\circ}C$와 2$0^{\circ}C$ 조건에서 배양 2일후부터 방출되기 시작하였으며, 배양 9일후 2$0^{\circ}C$ 조건에서 가장 높은 96.7$\pm$5.8%의 난방출율을 보였다. 또한 15$^{\circ}C$ 조건에서는 배양 9일후 76.7%의 난방출율을 보였다. 1$0^{\circ}C$와 $25^{\circ}C$ 조건에서는 배양 11일까지 36.7%의 난방출율을 나타내어 온도 조건에 따라 난방출 비율에 차이를 보였다. 따라서 이러한 실내 배양 결과를 다량의 모조를 조기에 성숙시키기 위해 모조 수용 수조의 수온을 자연수온보다 2~5$^{\circ}C$ 높은 12~15$^{\circ}C$ 조건으로 유지하여 15일간의 수조 관리 후 모조의 대량 유배 방출을 유도할 수 있었다. 모조 성숙을 위한 사육 수조의 수온을 2$0^{\circ}C$ 이상으로 가온할 경우 엽체의 끝녹음을 유발하였으며 가온에 따르는 가온 비용이 수반되므로 엽체의 난방출율이 70% 이상에 도달하는 15$^{\circ}C$ 조건으로 유지하는 것이 경제적일 뿐만 아니라 엽체의 건전도 유지에도 바람직하였다. 유배의 초기생장은1$0^{\circ}C$와15$^{\circ}C$의 온도조건에서 길이생장이 빠르게 증가하여, 배양 35일 후 15$^{\circ}C$와 60 $\mu$molm$^{-2}$ s$^{-1}$의 조건에서 3.9$\pm$0.2mm로 가장 높은 값을 나타내었다. 엽체의 초기 길이생장은 15$^{\circ}C$, 60 $\mu$molm$^{-2}$ -s$^{-1}$의 조도 조건에서 가장 우세하였으며, 다음으로 30과 100 $\mu$molm$^{-2}$ s$^{-1}$의 조건 순으로 나타났다. 2$0^{\circ}C$와 $25^{\circ}C$의 온도 조건에서는 각각 1.8~2.1mm로 길이생장에 있어 유의한 차이가 없는 것으로 나타났다.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.4
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• pp.32-50
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• 2019

The present study examines the circumstances around the establishment of the Seonyu Eight Scenic Spots (仙遊八景) in Gogunsan Islands and the characteristics of the landscape of each viewing point. The study conclusions are as follows. First, since the scenic spots were first established in 1969, their content and sequences have been changed several times, and their names have also been changed to some extent. Until the 1970s, these scenic spots did not have official names for them and were often specified as 'Gogunsan Eight Scenic Spots', and excluded 'the Musan Twelve Peaks (巫山十二峰)'. In addition, viewing points of the eight scenic spots varied across periods. This suggests that, for the early form of Seonyu Eight Scenic Spots, the picturesque scenery of Gogunsan Islands, and Seonyudo Island in particular, was chosen, while eight scenic spots in its vicinity were regarded. Second, the Seonyu Eight Scenic Spots of the early 2000s, which has all eight scenic spots of now, follows the nomenclature of the traditional eight scenic spots by specifying the sequence number with a refined name in four syllables. Its first scenic spot was Mangju Waterfall (望主瀑布) and its eighth scenic spot was Seonyu Sunset (仙遊落照); currently, the first scenic spot is Seonyu Sunset and the second scenic spot is Mangju Waterfall. Such change in the sequence of viewing points resulted from differences in representative landscape resources between the periods. Third, the lack of structure and finesse due to continuous changes is directed related to the identity issue of the Seonyu Eight Scenic Spots. Above all, it is unclear by whom and when Seonyu Eight Scenic Spots was established, and there are clear traces of following the eight scenic spots in the neighboring areas such as Okgu (沃溝) and Impi (臨陂)'s Eight Scenic Spots. Moreover, it is evaluated to have an unrefined, incomplete structure due to the lack of clarity in the knowledge and information about viewing objects, when to view, and historical and cultural background. Fourth, the first scenic spot, Seonyu Sunset, has the image that dominates the entire Eight Scenic Spots. The temporary landscape, the sunset, became the best view because it was perceived as the entirety of the landscape created by the fusion of the beautiful natural elements of Seonyudo Island. Therefore, there is ample room for raising the value of other landscape resources of Gogunsan Islands by utilizing the existing perception of exploring the entire landscape of Seonyudo Island and Gogunsan Islands starting with Seonyu Sunset. This likely requires additional work to imbue each viewing point with identity and completion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.1
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• pp.11-26
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• 1984

The aim of this study is to establish a synthetical optimal method that simultaneously analyze and design reinforced concrete flat slab-column structures involving multi-constraints and multi-design variables. The variables adopted in this mathematical models consist of design variables including sectional sizes and steel areas of frames, and analysis variable of the ratio of bending moment redistribution. The cost function is taken as the objective function in the formulation of optimal problems. A number of constraint equations, involving the ultimate limit state and the serviceability limit state, is derived in accordance with BSI CP110 requirements on the basis of limit state design theory. Both objective function and constraint equations derived from design variables and an analysis variable generally become high degree nonlinear problems. Using SLP as an analytical method of nonlinear optimal problems, an optimal algorithm is developed so as to analyze and design the structures considered in this study. The developed algorithm is directly applied to a few reinforced concrete flat slab-column structures to assure the validity of it and the possibility of optimization From the research it is found that the algorithm developed in this study is applicable to the optimization of reinforced concrete flat slab column structures and it converges to a optimal solution with 4 to 6 iterations regardless of initial variables. The result shows that an economical design can be possible when compared with conventional designs. It is also found that considering the ratio of bending moment redistribution as a variable is reasonable. It has a great effect on the composition of optimal sections and the economy of structures.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.1
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• pp.42-55
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• 2008

Purpose: A new health policy, referred to as the National Health Screening Program for Infants and Children, was launched in November 2007 by the Ministry of Health and Welfare and National Health Insurance Corporation in Korea. We have developed a nutrition-counseling program that was incorporated into this project. Methods: We reviewed the nutritional guidelines published by The Korean Pediatric Society and internationally well-known screening programs such as Bright Future in the United States. We also reviewed the recent Korean national surveys on nutritional issues, including the Korea National Health and Nutrition Examination Survey (KNHANES) and the 2005 National Survey of Physical Body and Blood Pressure in Children and Adolescents. The development of questions, pamphlets, computer programs, and manuals for doctors was carried out after several meetings of researchers and governmental officers. Results: We summarized the key nutritional issues according to age, including breastfeeding in infants, healthier complementary feeding, and prevention of iron deficiency anemia, establishment of healthier diets, as well as dietary prevention of overweight children with an emphasis on physical exercise. We have constructed a new Korean nutrition questionnaire and an anticipatory guidance program based on the primary care schedule of visits at 4, 9, 18, 30, and 60 months of age. Five to eight questions were asked at each visit and age-matched pamphlets for parents and guidelines for doctors were provided. Conclusion: We developed a nutrition-counseling program based on recent scientific evidence for Korean infants and children. Further research on this national program for screening the nutritional problems in detail and setting the therapeutic approaches may help identify areas of success as well as those that need further attention.

• Journal of Global Scholars of Marketing Science
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• v.20 no.1
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• pp.70-79
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• 2010

There has been some research conducted that addressed immoral consumer behaviors in Korea; however, most of this research focused on purchasing counterfeits or shoplifting. High return rates of apparel and used apparel returns have been acknowledged as problem areas within the fashion industry. However, very few researchers have addressed this issue. Therefore, the goal of this research was to explore consumer's retail borrowing experience using a mixed methods approach. In study 1 Korean consumer's retail borrowing experiences was explored through focus group interviews. Findings informed study 2 an examination of apparel consumers' attitudes toward retail borrowing behavior via an online survey. Findings assist both researchers' and practitioners' understanding of retail borrowing behaviors and provide insight into retail borrowing issues in the apparel retail industry. For study 1, five focus-group interviews were conducted with seven panels of individuals that had retail borrowing experience within the past year. Thirty-five Korean consumers who lived in a metropolitan area participated in the focus group interviews. Most of consumers were in their 20's (n=21) and were women (n=24). Most participants purchased apparel items from a retail store and returned the worn items for either a full refund or exchanged the worn item for another item. Motives underlying retail borrowing behavior included social needs, job-related needs, fashion needs, and "smart shopping." Similar to existing research findings from other countries, social needs were the most frequently mentioned cause of retail borrowing in fashion stores. Consumers' moral values, attitude toward large corporations, and prior retail borrowing experience were mentioned as possible factors affecting consumers' retail borrowing behavior. For study 2, the questionnaire used to gather the data was developed based on the findings of part I and existing research. Questions concerning consumers' moral beliefs, sensation seeking tendencies, self-worth, past retail job experience, retail borrowing experience, and some demographic characteristics were included in the questionnaire. The data were collected via an online survey using an online panel provided by a commercial online research company located in Seoul, Korea. In order to obtain various consumers, a quota sample was (male: female=1:1, 20's:30's:40's=1:1:1, retail experience: no retail experience=1:3) obtained from the company. A total of 401 consumers who had shopped for apparel items during the prior 6 months participated in the online survey. The results indicated that 19.7% of the respondents reported they had experience borrowing fashion merchandise. Among these individuals, male borrowers (57%) outnumbered female borrowers. In terms of age distribution, x2 revealed that there was a statistical difference between respondents with and without retail borrowing experiences: 41.8% of the respondents with retail borrowing experience were in their 40's, while respondents without retail borrowing experience were evenly distributed between their 20's to 40's. There was also a significant difference between respondents with and without retail borrowing experience in terms of income: respondents with retail borrowing experience tended to have higher incomes than those without retail borrowing experience. T-tests were performed to compare respondents' fashion shopping behavior, moral beliefs, sensation-seeking tendencies, and attitudes toward retail borrowing behavior between participants with and without retail borrowing experience. As compared to those with no borrowing experience, respondents with experience tended to shop for fashion items more frequently and spent more on shopping for fashion items. Consumers with experience borrowing tended to have higher sensation-seeking tendencies than consumers without retail borrowing experience. A regression analysis revealed that attitudes toward fashion retail borrowing were negatively related to consumers' moral beliefs, but positively related to monthly fashion shopping frequency, sensation-seeking tendencies, and past fashion retail borrowing experience. Among these variables, past retail borrowing experience was the most significant predictor, followed by moral beliefs. This research serves as an initial attempt to address the motives that underlie retail borrowing behaviors and the factors affecting those behaviors. The findings of this study may facilitate an understanding of the consumer's retail borrowing, which will provide a basis for approaches that may help decrease retail borrowing and inappropriate returns at fashion retail stores. The findings may also provide materials for consumer education over the long term. In order to better understand fashion retail borrowing behavior, more research is needed in the future.