• 대한치과의사협회지
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• 제57권12호
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• pp.728-735
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• 2019

Objective: Previous studies suggested the potential influence of YouTube videos regarding dentistry on the mass population. However, there was not any clear investigation for Korean population. We aimed to systemically analyze the type of the dentistry-related videos uploaded on YouTube Korea and the accounts used for uploading, and to assess their effect on the view count of the content. Methods: Classification, type of the accounts, and view count of the videos listed by the keyword 'dentistry' were analyzed, which were uploaded on YouTube Korea platform from September 2017 to April 2019. Kruskal-Wallis test with post hoc analysis was used to assess the effect of the classification of the videos and the type of accounts on the view count. Results: 1.026 videos were enrolled to the analysis. Primary classification of the videos was information/education, advertisement, life, news, child contents, autonomous sensory meridian response, broadcast, cartoon/game, humor, and music. Secondary classification of the videos was dental experience, advertisement, role-playing, information/education., humor, cartoon/game, child contents, life, and broadcast. Type of the accounts was dentistry associates, general public, media company, and government office (sorted by frequency). Subject of the most videos (93.6%) was general public. There was statistically significance in the view count of the videos according to the primary and secondary classifications, the account used for uploading, and target subject of the videos. Conclusion: Dentists and their associates should recognize the importance of YouTube platform and try to monitor and intervene the dentistry-related contents, considering its huge impact on the general public.

• Asian Journal of Atmospheric Environment
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• 제9권3호
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• pp.228-235
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• 2015

In order to clarify the thermal and hygroscopic properties of indoor particulate matter (PM) in a semiclosed subway space, which is critically important for understanding of the distinctive particle formation processes as well as the assessment of their health effects, the size-resolved PMs (i.e., $PM_{2.5}$ and $PM_{10-2.5}$) were intensively collected on the platform of Miasageori station on the Seoul Subway Line-4. The elemental concentrations in soluble and insoluble fractions were determined by PIXE from the bulkily pretreated $PM_{2.5}$. The thermal and hygroscopic characteristics of individual particles were investigated via a combination of the unique pretreatment techniques (i.e., the high-temperature rapid thermal process and the water dialysis) and SEM-EDX analysis. Iron and calcium were unequaled in insoluble and soluble $PM_{2.5}$ fractions, respectively, with overwhelming concentration. The SEM-EDX's elemental net-counts for the pre- and post-pyrolyzed PMs newly suggest that magnesium and several elements (i.e., silica, aluminum, and calcium) may be readily involved in the newly generated subway fine PM by a high-temperature thermal processing when trains are breaking and starting. Through the water dialysis technique, it turned out that calcium has meaningful amount of water soluble fraction. Furthermore, the concentrations of the counter-ions associated with the calcium in subway $PM_{10-2.5}$ were theoretically estimated.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.106-112
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• 2020

Analyzing vitamin D levels is important for monitoring health conditions because vitamin D deficiency is associated with various diseases such as rickets, osteomalacia, cardiovascular disorders and some cancers. However, vitamin D concentration in the blood is very low with optimal level of 75 nmol/L, making quantitative analysis difficult. The objective of this study was to develop a highly sensitive analysis method for vitamin D using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS). 25-hydroxyvitamin D (25(OH)D), which has been used as an indicator of vitamin D metabolites in human biofluids was chemically derivatized using a secosteroid signal enhancing tag (SecoSET) with powerful dienophile and permanent positive charge. The SecoSET-derivatized 25(OH)D provided good linearity (R² > 0.99) and sensitivity (limit of quantitation: 11.3 fmol). Chemical derivatization of deuterated 25-hydroxyvitamin D₃ (d₆-25(OH)D3) with SecoSET enabled absolute quantitative analysis using MALDI-MS. The highly sensitive method could be successfully applied into monitoring of quantitative changes of bioactive vitamin D metabolites after treatment with ketoconazole to inhibit 1α-hydroxylase reaction related to vitamin D metabolism in human breast cancer cells. Taken together, we developed a MALDI-MS-based platform that could quantitatively analyze vitamin D metabolites from cell products, blood and other biofluids. This platform may be applied to monitor various diseases associated with vitamin D deficiency such as rickets, osteomalacia and breast cancer.

• 한국콘텐츠학회논문지
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• 제13권4호
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• pp.8-16
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• 2013

U-Healthcare의 활성화를 위해 모바일 기기를 활용한 원격진료 및 진료지원에 대한 연구가 활발하다. 특히 원격처방시스템을 허용하는 의료법이 개정되면 모바일 처방시스템에 관한 연구는 급속도로 확산될 것이다. 그러나 모바일 앱은 모바일 플랫폼의 특성에 따라서 호환성이 떨어지는 특징을 가지므로, 플랫폼에 맞게 다시 개발해야 하는 제약사항을 가진다. 이러한 문제점을 보완하기 위해 이 논문에서는 모바일 표준 웹 개발 언어로 대두된 HLTML5와 자바스크립트 라이브러리인 jQuery Mobile을 이용하여 모바일 웹 처방 인터페이스를 설계한다. 또한, 기존의 병원정보시스템과의 자료 공유를 위해서 표준 프로토콜인 HL7을 기반으로 하는 메시지 형태로 변환하는 기능을 추가한다. HL7 메시지 송신을 통해 기존의 병원정보시스템과의 연동이 가능하도록 한다. 제안 시스템은 모바일 플랫폼에 독립적이고, 범용 컴퓨터에서도 호환성을 가지므로 다양한 환경에서 활용이 가능한 장점을 가진다.

• Journal of Periodontal and Implant Science
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• 제50권4호
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• pp.209-225
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• 2020

Purpose: Marginal bone loss (MBL) is an important clinical issue in implant therapy. One feature that has been cited as a contributing factor to this bone loss is peri-implant mucosal thickness. Therefore, in this report, we conducted a systematic review of the literature comparing bone remodeling around implants placed in areas with thick (≥2-mm) vs. thin (<2-mm) mucosa. Methods: A PICO question was defined. Manual and electronic searches were performed of the MEDLINE/PubMed and Cochrane Oral Health Group databases. The inclusion criteria were prospective studies that documented soft tissue thickness with direct intraoperative measurements and that included at least 1 year of follow-up. When possible, a meta-analysis was performed for both the overall and subgroup analyses. Results: Thirteen papers fulfilled the inclusion criteria. A meta-analysis of 7 randomized clinical trials was conducted. Significantly less bone loss was found around implants with thick mucosa than around those with thin mucosa (difference, -0.53 mm; P<0.0001). Subgroups were analyzed regarding the apico-coronal positioning, the use of platform-matched vs. platform-switched (PS) connections, and the use of cement-retained vs. screw-retained prostheses. In these analyses, thick mucosa was found to be associated with significantly less MBL than thin mucosa (P<0.0001). Among non-matching (PS) connections and screw-retained prostheses, bone levels were not affected by mucosal thickness. Conclusions: Soft tissue thickness was found to be correlated with MBL except in cases of PS connections used on implants with thin tissues and screw-retained prostheses. Mucosal thickness did not affect implant survival or the occurrence of biological or aesthetic complications.

• 한국전문물리치료학회지
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• 제4권3호
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• pp.34-44
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• 1997

The purpose of this study was to compare the balance ability at different foot angle with KAT 2000 (Breg, Inc., Vista, CA. 1994). Forty-nine (male 24, female 25) normal subjects participated in this study. All subjects were assessed under two conditions. One was eye-opened condition and the other one was eye-closed one in 3 psi surface condition. All subjects were tested at different foot angle that were toe-in $25^{\circ}$, $45^{\circ}$, toe-out $25^{\circ}$ and $45^{\circ}$. The subject attempted to keep the platform as stable as possible with eyes closed and with eyes opened for every 20 seconds. The starting position was that subject crossed their arms across chest and flexed knees slightly. The results of each test were showed by a score on screen, which meant balance index. The se collected data were analyzed by using oneway ANOVA, Scheffe test, and t-test. The results of this study were as follows: 1. When the foot angle were changed, balance index was the lowest in toes-out $25^{\circ}$ condition and greatest with toes-in $45^{\circ}$ with eyes opened and with eyes closed. There were statistically significant difference with eyes opened and with eyes closed (p<0.05). 2. There was statistically significant difference in balance index according to visual condition and the balance index tested with eyes closed was higher than with eyes closed(p<0.05). 3. There was statistically significant difference in balance index by gender(p<0.05).

• 한국안전학회지
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• 제35권5호
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• pp.1-8
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• 2020

Mobile elevating work platforms (MEWPs) consist of a work platform, extending structure, and chassis, and are used to move persons to working positions. MEWPs are useful but are composed of pieces of equipment, and accidents do occur owing to equipment defects. Among these defects, accidents caused by the fracture of bolts fixed to the extension structure and swing system are increasing. This paper presents a failure analysis of the fixing bolts of MEWP. Standard procedure for failure analysis was employed in this investigation. Visual inspection, chemical analysis, tensile strength measurement, microstructural characterization, fractography analysis by Optical Microscope(OM) and Scanning Electron Microscopy(SEM), and finite element analysis (FEA) were used to analyze the failure of the fixing bolts. Using this failure analysis approach, we found the root cause of failure and proposed a means for solving this type of failure in the future. First, the chemical composition of the fixing bolt is obtained by a spectroscopy chemical analysis method, which determined that the chemical composition matched the required standard. The tensile test showed that the tensile and yield strengths were within the required capacity. The stress analysis was carried out at five different boom angles, and it was determined that the fixing bolt of MEWP can withstand the loads at all the boom angles. The outcomes of the fatigue analysis revealed that the fixing bolt fails before reaching the design requirements. The results of the fatigue analysis showed primarily that the failure of the fixing bolt was due to fatigue. A visual inspection of the fractured section of the fixing bolt also confirmed the fatigue failure. We propose a method to prevent failure of the fixing bolt of the MEWP from four different standpoints: the manufacturer, safety certification authority, safety inspection agency, and owner.

• 한국ITS학회 논문지
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• 제20권5호
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• pp.172-185
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• 2021

자율주행시대가 우리 삶에 다가오면서 삶의 변화에 많은 영향을 미칠 것으로 예상된다. 자율주행자동차가 등장하면 운전자의 부담을 줄임으로 차내에서 생산적 가치가 확장되는 만큼 이를 평가할 수 있는 지표개발이 필요하다. 이번 연구는 경기도 직장인 중 승용차를 이용하는 통근자를 대상으로 자율주행 자동차가 통근시간 및 통근시간 만족도에 어떠한 영향을 미치는지 분석하였다. 통근시간 및 통근시간 만족도는 비선형 관계(V)가 도출되었다. 여기서, 자율주행시대에 영향받을 가능성이 높은 비선형 구간인 통근시간 70분 이상영역을 중심으로 이항로지스틱 모형을 통해 분석하였다. 분석결과 자율주행시대의 영향변수로는 건강도, 수면시간, 근무시간, 여가시간 등이 도출되었다. 자율주행자동차의 등장은 이러한 변수를 개선시킬 가능성이 높으므로 장거리 통근자의 통근시간 만족도는 개선될 가능성이 높다.

• 한국건설안전학회 논문집
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• 제2권1호
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• pp.9-15
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• 2019

건설산업에서의 안전 수준 향상 노력에도 불구하고, 건설산업은 타 산업에 비해 높은 사망자수를 보이고 있다. 이러한 높은 사고율은 건설산업의 안전관리 측면에서 효과적인 대책이 필요함을 명확히 의미한다. 기존의 연구에서 주장하듯, 사고의 발생 가능성이 높은 공종이나 기인물을 파악하고 이에 적합한 안전대책을 세우는 것이 중요하다. 다수의 추락관련 건설재해가 작업발판 및 안전통로에서 발생한다는 점을 고려해보면, 안전관리 측면에서 가시설물을 중점적으로 다루어야 할 것이다. 이를 위해 본 연구에서는, 작업발판 및 안전통로와 관련된 6개년 1663개의 사망사고를 공사규모, 공정률, 공종, 직종에 의해 분류하고, 각 사망재해가 발생한 사례들을 분석함으로써 보다 중점적으로 관리되어야할 요소를 추출하였다.

• 산업식품공학
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• 제21권1호
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• pp.12-21
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• 2017

Foods are becoming more customized and consumers demand food that provides great taste and appearance and that improves health. Food three-dimensional (3D)-printing technology has a great potential to manufacture food products with customized shape, texture, color, flavor, and even nutrition. Food materials for 3D-printing do not rely on the concentration of the manufacturing processes of a product in a single step, but it is associated with the design of food with textures and potentially enhanced nutritional value. The potential uses of food 3D-printing can be forecasted through the three following levels of industry: consumer-produced foods, small-scale food production, and industrial scale food production. Consumer-produced foods would be made in the kitchen, a traditional setting using a nontraditional tool. Small-scale food production would include shops, restaurants, bakeries, and other institutions which produce food for tens to thousands of individuals. Industrial scale production would be for the mass consumer market of hundreds of thousands of consumers. For this reason, food 3D-printing could make an impact on food for personalized nutrition, on-demand food fabrication, food processing technologies, and process design in food industry in the future. This article review on food materials for 3D-printing, rheology control of food, 3D-printing system for food fabrication, 3D-printing based on molecular cuisine, 3D-printing mobile platform for customized food, and future trends in the food market.