• Title/Summary/Keyword: Coping type

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A COMPARISON OF FRACTURE STRENGTHS OF PORCELAIN-FUSED-TO-TITANIUM CROWN AMONG TITANIUM SURFACE COATING TREATMENTS (타이타늄 표면 코팅 처리에 따른 타이타늄도재관의 파절강도 비교)

  • Kim, Ji-Hye;Park, Sang-Won;Vang, Mong-Sook;Yang, Hong-So;Park, Ha-Ok;Lim, Hyun-Pil;Oh, Gye-Jeong;Kim, Hyun-Seung;Lee, Kwang-Min;Lee, Kyung-Ku
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.2
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    • pp.203-215
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    • 2007
  • Statement of problem: Titanium and its alloy, with their excellent bio-compatibility and above average resistance to corrosion, have been widely used in the field of dentistry. However, the excessive oxidization of titanium which occurs during the process of firing on porcelain makes the bonding of titanium and porcelain more difficult than that of the conventional metal-porcelain bonding. To solve this problem related to titanium-porcelain bonding, several methods which modify the surfaces, coat the surfaces of titanium with various pure metals and ceramics, to enable the porcelain adhesive by limiting the diffusion of oxygen and forming the adhesive oxides surfaces, have been investigated. Purpose: The purpose of this study was to know whether the titanium-porcelain bonding strength could be enhanced by treating the titanium surface with gold and TiN followed by fabrication of clinically applicable porcelain-fused-to-titanium crown Material and method: The porcelain-fused-to-titanium crown was fabricated after sandblasting the surface of the casting titanium coping with $Al_2O_3$ and treating the surface with gold and TiN coating followed by condensation and firing of ultra-low fusing porcelain. To compare with porcelain-fused-to-titanium crowns, porcelain-fused-to-gold crowns were fabricated and used as control groups. The bonding strengths of porcelain-fused-to-gold crowns and porcelain-fused-totitanium crowns were set for comparison when the porcelain was fractured on purpose to get the experimental value of fracture strength. Then, the surface were examined by SEM and each fracturing pattern were compared with each other Result:Those results are as follows. 1. The highest value of fracture strength of porcelain-fused-to-titanium crowns was in the order of group with gold coating, group with TiN coating, group with $Al_2O_3$ sandblasting. No statistically significant difference was found among the three (P>.05). 2. The porcelain-fused-to-gold crowns showed the highest value in bonding strength. The bonding strength of crowns porcelain-fused-to-titanium crowns of rest groups showed bonding strength reaching only 85%-94% of that of PFG, though simple comparision seemed unacceptable due to the difference in materials used. 3. The fracturing patterns between metal and porcelain showed mixed type of failure behavior including cohesive failure and adhesive failure as a similar patterns by examination with the naked eye and SEM. But porcelain-fused-to-gold crowns showed high incidence of adhesive failure and porcelain-fused-to-titanium crowns showed high incidence of cohesive failure. Conclusion: Above results proved that when fabricating porcelain-fused-to-titanium crowns, treating casting titanium surface with gold or TiN was able to enhance the bonding strength between titanium and porcelain. Mean value of masticatory force was found to showed clinically acceptable values in porcelain bonding strength in all three groups. However, more experimental studies and evaluations should be done in order to get better porcelain bonding strength and various surface coating methods that can be applied on titanium surface with ease.

A Study on the Effects of Meterological Factors on the Distribution of Agricultural Products: Focused on the Distribution of Chinese Cabbages (기상요인이 농산물 유통에 미치는 영향에 관한 연구: 배추 유통 사례를 중심으로)

  • Lee, Hyunjoung;Hong, Jinhwan
    • Journal of Distribution Research
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    • v.17 no.5
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    • pp.59-83
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    • 2012
  • Agriculture is a primary industry that influenced by the weather or meterological factors more than other industry. Global warming and worldwide climate changes, and unusual weather phenomena are fatal in agricultural industry and human life. Therefore, many previous studies have been made to find the relationship between weather and the productivity of agriculture. Meterological factors also influence on the distribution of agricultural product. For example, price of agricultural product is determined in the market, and also influenced by the weather of the market. However, there is only a few study was made to find this link. The objective of this study is to investigate the effects of meterological factors on the distribution of agricultural products, focusing on the distribution of chinese cabbages. Chinese cabbage is a main ingredient of Kimchi, and basic essential vegetable in Korean dinner table. However, the production of chinese cabbages is influenced by weather and very fluctuating so that the variation of its price is so unstable. Therefore, both consumers and farmers do not feel comfortable at the unstable price of chinese cabbages. In this study, we analyze the real transaction data of chinese cabbage in wholesale markets and meterological factors depending on the variety and geography. We collect and analyze data of meterological factors such as temperatures, humidity, cloudiness, rainfall, snowfall, wind speed, insolation, sunshine duration in producing and consuming region of chinese cabbages. The result of this study shows that the meterological factors such as temperature and humidity significantly influence on the volume and price of chinese cabbage transaction in wholesale market. Especially, the weather of consuming region has greater correlation effects on transaction than that of producing region in all types of chinese cabbages. Among the whole agricultural lifecycle of chinese cabbages, 'seeding - harvest - shipment - wholesale', meterological factors such as temperature and rainfall in shipment and wholesale period are significantly correlated with transaction volume and price of crops. Based on the result of correlation analysis, we make a regression analysis to verify the meterological factors' effects on the volume and price of chines cabbage transaction in wholesale market. The results of stepwise regression analysis are shown in

    and
    . The type of chinese cabbages are categorized by 5 types, i.e. alpine, gimjang for winter, spring, summer, and winter crop, and all of the regression models are shown significant relationship. In addition, meterological factors in shipment and wholesale period are entered more in regression model than those in seeding and harvest period. This result implies that weather in consuming region is also important in the distribution of chinese cabbages. Based on the result of this study, we find several implications and recommendations for policy makers of agricultural product distribution. The goal of agricultural product distribution policy is to insure proper price and production cost for farmers and provide proper price and quality, and stable supply for consumers. Therefore, coping with the uncertainty of weather is very essential to make a fruitful effect of the policy. In reality, very big part of consumer price of chinese cabbage is made up of the margin of intermediaries, because they take the risk. In addition, policy makers make efforts for farmers to utilize AWIS (Agricultural Weather Information System). In order to do that, it should integrate the relevant information including distribution and marketing as well as production. Offering a consulting service to farmers about weather management is also expected to be a good option in agriculture and weather industry. Reflecting on the result of this study, the distribution authorities can offer the guideline for the timing and volume of harvest, and it is expected to contribute to the stable equilibrium of supply and demand of agricultural products.

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  • An Exploratory Study on Female Caregivers' Experiences of Aggression by Older Residents in Nursing Homes (노인요양시설 입소노인에 의한 여성요양보호사의 폭력 경험에 대한 탐색적 연구)

    • Yoo, Seong Ho;Kim, Bo Kyung;Moon, Yu Jin;Shim, Il Kwang;Cho, Hee Ju
      • 한국노년학
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      • v.36 no.4
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      • pp.1037-1058
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      • 2016
    • This study aims to investigate the female caregivers'experiences of aggression by nursing home residents, and to identify the policy strategies for violence prevention referred by the female caregivers. A total of 121 female caregivers with more than 6 months of working experiences had participated in this study. Of these, 56.2% had experienced verbal aggression, 51.2% physical aggression, and 27.3% sexual aggression, which reveals that client violence toward caregivers in nursing homes was at an alarming level. Although, physical and verbal violences were mostly caused unintentionally, about a half of the sexual aggression were caused deliberately. Aggression occurred the most when caregivers were providing the following services: changing the diapers or clothes, giving a bath, and serving meals. It was found that 'hitting' was the most common form of physical aggression and it was 'swearing' and 'touching or physical contacting' in the case of verbal and sexual aggression, respectively. Though there was a difference depending on the type of aggression, the most frequent reactions against client violence were to start a conversation or calm down the nursing home residents, and to leave the scene or ignore the incident. This means that the caregivers are coping very passively through resolving the aggressions by themselves, or overlooking the situation. The most frequently recommended strategy to prevent resident aggression was to provide educational programs on violence prevention to nursing home residents and caregivers(42.7%). Compared to the previous studies, this study indicates some differentiated strategies to prevent violence in nursing homes, which include hiring male caregivers, assuring directors to pay closer attention toward caregivers, using refined language between caregivers and residents, and keeping caregivers to wear appropriate clothes. Based on the study results, some policy recommendations on the prevention of client violence in nursing homes were suggested.

    The Effect of the Shift Work on Drinking and the Mediating Effect of Sleep (교대근무가 음주에 미치는 영향 및 수면의 매개효과)

    • Jeong, Heeju;Kong, Ji-Sook;Kim, Mi Kyung;Kim, Seok Hyeon
      • Korean Journal of Psychosomatic Medicine
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      • v.29 no.2
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      • pp.111-120
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      • 2021
    • Objectives : Shift work has been known to cause various health problems by making it difficult for humans to adapt to their natural circadian rhythms. In particular, shift workers tend to complain of sleep difficulties associated with work schedules, and sometimes use alcohol as a self-medication to induce sleep. To date, no clear mechanism has been identified regarding the link between shift work and sleep, between shift work and drinking. This study aims to confirm the relationship between shift work and sleep, and to analyze whether the change in sleep caused by shift work causes drinking. Methods : This study included 11360 people (5704 men and 5656 women) among the Korean National Health and Nutrition Survey data in 2014, 2016 and 2018. The work type between 6am-6pm was defined as day work, and other work types were defined as shift work. Using logistic regression analysis, the relationship between shift work and sleep quality, shift work and high risk drinking, drinking amount at 1 time, drinking frequency were analyzed. In addition, we analyzed whether sleep mediates the relationship between shift work and drinking using mediated analysis. Results : Shift work showed a significant negative relationship with sleep quality in men and women (male OR=1.37, 95% CI 1.11-1.70, female OR=1.26, 95% CI=1.05-1.50). There was no significant relationship between shift work and alcohol in the case of men, but in the case of women, there was a significant positive relationship between shift work and the number of alcohol consumption (OR=1.34, 95% CI=1.04-1.72). When mediation analysis was conducted, it was found that women's sleep quality partially mediated the relationship between shift work and the frequency of drinking. Conclusions : The results of this study suggest that shift work causes sleep difficulties, and in the case of women, drinking can be induced through the partial mediating effect of sleep. Considering that women are more likely to choose drinking as a coping method for sleep problems, more active interventions for female shift workers are needed.

    Automatic gasometer reading system using selective optical character recognition (관심 문자열 인식 기술을 이용한 가스계량기 자동 검침 시스템)

    • Lee, Kyohyuk;Kim, Taeyeon;Kim, Wooju
      • Journal of Intelligence and Information Systems
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      • v.26 no.2
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      • pp.1-25
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      • 2020
    • In this paper, we suggest an application system architecture which provides accurate, fast and efficient automatic gasometer reading function. The system captures gasometer image using mobile device camera, transmits the image to a cloud server on top of private LTE network, and analyzes the image to extract character information of device ID and gas usage amount by selective optical character recognition based on deep learning technology. In general, there are many types of character in an image and optical character recognition technology extracts all character information in an image. But some applications need to ignore non-of-interest types of character and only have to focus on some specific types of characters. For an example of the application, automatic gasometer reading system only need to extract device ID and gas usage amount character information from gasometer images to send bill to users. Non-of-interest character strings, such as device type, manufacturer, manufacturing date, specification and etc., are not valuable information to the application. Thus, the application have to analyze point of interest region and specific types of characters to extract valuable information only. We adopted CNN (Convolutional Neural Network) based object detection and CRNN (Convolutional Recurrent Neural Network) technology for selective optical character recognition which only analyze point of interest region for selective character information extraction. We build up 3 neural networks for the application system. The first is a convolutional neural network which detects point of interest region of gas usage amount and device ID information character strings, the second is another convolutional neural network which transforms spatial information of point of interest region to spatial sequential feature vectors, and the third is bi-directional long short term memory network which converts spatial sequential information to character strings using time-series analysis mapping from feature vectors to character strings. In this research, point of interest character strings are device ID and gas usage amount. Device ID consists of 12 arabic character strings and gas usage amount consists of 4 ~ 5 arabic character strings. All system components are implemented in Amazon Web Service Cloud with Intel Zeon E5-2686 v4 CPU and NVidia TESLA V100 GPU. The system architecture adopts master-lave processing structure for efficient and fast parallel processing coping with about 700,000 requests per day. Mobile device captures gasometer image and transmits to master process in AWS cloud. Master process runs on Intel Zeon CPU and pushes reading request from mobile device to an input queue with FIFO (First In First Out) structure. Slave process consists of 3 types of deep neural networks which conduct character recognition process and runs on NVidia GPU module. Slave process is always polling the input queue to get recognition request. If there are some requests from master process in the input queue, slave process converts the image in the input queue to device ID character string, gas usage amount character string and position information of the strings, returns the information to output queue, and switch to idle mode to poll the input queue. Master process gets final information form the output queue and delivers the information to the mobile device. We used total 27,120 gasometer images for training, validation and testing of 3 types of deep neural network. 22,985 images were used for training and validation, 4,135 images were used for testing. We randomly splitted 22,985 images with 8:2 ratio for training and validation respectively for each training epoch. 4,135 test image were categorized into 5 types (Normal, noise, reflex, scale and slant). Normal data is clean image data, noise means image with noise signal, relfex means image with light reflection in gasometer region, scale means images with small object size due to long-distance capturing and slant means images which is not horizontally flat. Final character string recognition accuracies for device ID and gas usage amount of normal data are 0.960 and 0.864 respectively.


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