• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권5호
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• pp.224-231
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• 2015

Objectives: The purpose of this study was to evaluate changes in the pharyngeal airway space and hyoid bone position after mandibular setback surgery with bilateral sagittal split ramus osteotomy (BSSRO) and to analyze the correlation between the amount of mandibular setback and the amount of change in pharyngeal airway space or hyoid bone position. Materials and Methods: From January 2010 to February 2013, a total of 30 patients who were diagnosed with skeletal class III malocclusion and underwent the same surgery (BSSRO) and fixation method in the Division of Oral and Maxillofacial Surgery, Department of Dentistry at the Ajou University School of Medicine (Suwon, Korea) were included in this study. Lateral cephalograms of the 30 patients were assessed preoperatively (T1), immediately postoperatively (T2), and 6 months postoperatively (T3) to investigate the significance of changes by time and the correlation between the amount of mandibular setback and the amount of change in the airway space and hyoid bone position. Results: Three regions of the nasopharynx, oropharynx, and hypopharynx were measured and only the oropharynx showed a statistically significant decrease (P<0.01). A significant posterior and inferior displacement of the hyoid bone was found 6 months after surgery (P<0.01). Analysis of the correlation between the amount of mandibular setback and the amount of final change in the airway space and hyoid bone position with Pearson's correlation showed no significant correlation. Conclusion: In this study, the oropharynx significantly decreased after mandibular setback surgery, and changes in the surrounding structures were identified through posteroinferior movement of the hyoid bone during long-term follow-up. Therefore, postoperative obstructive sleep apnea should be considered in patients who plan to undergo mandibular setback surgery, and necessary modifications to the treatment plan should also be considered.

• Tribology and Lubricants
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• 제33권5호
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• pp.228-233
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• 2017

Chemical Mechanical Polishing of chemically stable sapphire substrates is dominantly affected by the mechanical processing of abrasives, in terms of the material removal rate. In this study, we investigated the effect of electrostatic force between the abrasives and substrate, on the polishing. If potassium chloride (KCl) is added to slurry, water molecules are decomposed into $H^+$ and $OH^-$ ions, and the amount of ions in the slurry changes. The zeta potential of the abrasives decreases with an increase in the amount of $H^+$ ions in the stern layer; consequently, the electrostatic force between the abrasives and substrate decreases. The change in zeta potential of abrasives in the slurry is affected by the slurry pH. In acidic zones, the amount of ions bound to the abrasives increases if the amount of $H^+$ ions is increased by adding KCl. However, in basic zones, there is no change in the corresponding amount. In acidic zones, zeta potential decreases as molar concentration of potassium increases; however, it does not change significantly in basic zones. The removal rate tends to decrease with increase in molar amount of potassium in acidic zones, where zeta potential changes significantly. However, in basic zones, the removal rate does not change with zeta potential. The tendencies of zeta potential and that of the frictional force generated during polishing show strong correlation. Through experiments, it is confirmed that the contact probability of abrasives changes according to the electrostatic force generated between the abrasives and substrate, and variation in removal rate.

• Korean Chemical Engineering Research
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• 제56권1호
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• pp.14-23
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• 2018

The effect of dodecylbenzene sulfonic acid (DBSA) with different addition amount of DBSA ($M_{DBSA}$), temperatures and solvent-to-oil ratio (SOR, v/v) on asphaltene aggregation in a solvent deasphalting system was investigated. Increasing the $M_{DBSA}$ at SOR 10 and $55^{\circ}C$ caused the asphaltene removal ratio (ARR) to increase first, then maximize at 1 wt% of $M_{DBSA}$ and then decrease continuously. Based on the SARA (saturate, aromatic, resin, asphaltene) composition, the adsorption amount of DBSA on the asphaltene surface and the self-aggregation of the DBSA, the reason for the change in ARR with $M_{DBSA}$ was found due to the adsorption mechanism. In addition, the asphaltene-resin-DBSA colloidal size confirmed the change of adsorption behavior between the asphaltene and DBSA. Based on the results of this study, a hypothetical adsorption mechanism of DBSA on asphaltene aggregation in the solvent deasphalting system was conceived of and proposed.

• 한국기후변화학회지
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• 제9권1호
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• pp.75-80
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• 2018

The problem of water shortages and water related disasters caused by climate change has increased the seriousness of water problems and the importance of water treatment technology capable of securing clean water is expanding. In this study, we analyzed not only the water pollutant generated by the filtration system technology of various water treatment technologies but also the indirect greenhouse gas emissions generation, and analyzed the influence on the environment. The subjects of study are Fabric Filter, Reverse Osmosis System and Pressurized Microfiltration Device which are widely used for water treatment and we analyzed the impact on the environment using the Life Cycle Assessment (LCA) method using the electricity amount necessary for use, the water purification efficiency, the throughput per ton and the cost. The amount of greenhouse gas generated when the Pressurized Microfiltration Device operates for 1 year is $2.15E+04kg\;CO_2-eq$., Fabric Filter is $3.29E+04kg\;CO_2-eq$., and Reverse Osmosis System is $1.68E+05kg\;CO_2-eq$. As a result of analyzing the amount of greenhouse gas generated at the time of purifying 1 ton of the Pressurized Microfiltration Device and the conventional filtration system, the Pressurized Microfiltration Device was $20.5g\;CO_2-eq$., Fabric Filter was $34.7g\;CO_2-eq$., and Reverse Osmosis System was $191.7g\;CO_2-eq$. The amount of greenhouse gas generated was calculated to be 41.0% less than that of the Fabric Filter by the Pressurized Microfiltration Device and 89.3% less than the Reverse Osmosis System. From the viewpoint of climate change, it is necessary to select a filtration system that takes climate change into account, not from the viewpoint of water quality removal efficiency and economic efficiency according to future water treatment applications, and it is necessary to select a water treatment filtration system more researches and improvements will be made for.

• 산업융합연구
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• 제19권6호
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• pp.81-91
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• 2021

본 연구는 보수볼을 이용한 발목 근력 강화 운동과 테이핑이 엄지발가락가쪽휨증 환자의 정적과 동적 발바닥 압력에 어떠한 영향을 미치는지 알아보고자 실시하였다. 대상자는 엄지발가락가쪽휨증을 가지고 있는 20대 남녀 26명이며, 테이핑군(Taping group, TG; n=13)과 발목 강화 운동군 (Ankle strengthening group, ASG; n=13)으로 무작위로 배치하였고, 각 군은 총 4주에 걸쳐 해당 중재를 실시하였며, 중재 전과 후에 정적, 동적 발바닥 압력을 측정하였다. 집단 간 변화량의 차이를 알아보기 위해 독립 T검증을 실시하였고, 집단 내의 사전-사후값의 측정값 차이가 유의한지 알아보기 위해 대응표본 T검증을 실시하였다. 통계적 유의수준은 α= .05로 설정하였다. 발의 전체 체중에 대한 비율(Foot)은 왼쪽 발의 ASG가 TG에 비해 집단 내 변화량이 유의하게 감소하였고(p<.05), 발의 표면적(Surface area)에서는 오른쪽 발의 TG가 ASG에 비해 집단 내 변화량이 유의하게 증가하였다(p<.05). 발의 엎침 운동의 정도(MP/change ratio)는 오른발의 TG가 ASG에 비해 집단 내 변화량이 유의하게 감소하였고(p<.05), 발의 힘(Force)에서는 왼발의 TG가 ASG에 비해 집단 내 변화량이 유의하게 증가하였으며(p<.05), 집단 간의 변화에서는 TG의 변화량이 ASG의 변화량보다 유의한 차이가 나타났다(p<.05). 따라서 보수볼을 이용한 발목 강화 운동과 테이핑은 엄지발가락가쪽휨증을 가진 환자에게 효과적인 변화를 주기에는 부족하다고 할 수 있다.

• 한국토양비료학회지
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• 제48권5호
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• pp.384-390
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• 2015

Remote sensing can be used to provide information about the monitoring of crop situation. This study was conducted to estimate the amount of nitrogen present in paddy fields by measuring the amount of nitrogen in hairy vetch using an UAV (Unmaned Aerial Vehicle). NDVIs (Normalized Difference Vegetation Index) were calculated using UAV images obtained from paddy fields in Seocheon on May $14^{th}$ 2015. There was strong relationship between UAV NDVI and the amount of nitrogen in hairy vetch ($R^2=0.79$). Spatial distribution maps of green manure nitrogen were generated on each paddy field using the nitrogen-vegetation index relations to help farmers determine the amount of N fertilizers added to their rice fields after the application of green manure such as hairy vetch.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.80-81
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• 2019

Change requests occur persistently in the construction phase of a construction project. The law requires that the contract amount be adjusted in accordance with the relevant regulations when there is a change in the construction amount due to the design change in the construction contract. SAVE international, on the other hand, defines the value methodology as a systematic and structured approach to improving projects, products and processes. Design Changes in the construction projects require organizational efforts to improve value and quality. However, the law does not include change requests in which the VE object is fixed and related data is collected and function analysis can be derived in a short time. Therefore, it is necessary to apply VE to the design change procedure, which can further improve the value of construction work. The application derived from this study need to be presented as simply as possible without compromising the basic concept of VE. If the application is extended to the field and proved to be effective, it is expected to contribute to the overall value of construction work.

• 한국직업건강간호학회지
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• 제19권2호
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• pp.258-267
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• 2010

Purpose: This paper studies the influence of the case-management program on the change of blood sugar, lifestyle, and knowledge level of diabetes mellitus (DM) for medium-sized-enterprise employees suffering from DM. Method: Subjects, divided into experimental and control groups, are 59 workers with FBS higher than 126mg/$d{\ell}$ or under DM medication treatment in the medium-sized enterprises, being managed by two distinct university hospital group occupational health management service teams. The case management program for DM patients consists of 6 different processes in which each subject is treated. Result: FBS decreased in the experimental group after the program, while that of the control group increased significantly. In the experimental group, the amount of smoking, the frequency of drinking and the amount of drinking per week decreased. Also, the knowledge level for DM and the change of nutrition management showed significant increase. In the control group, the amount of smoking increased and the frequency of drinking, the amount of drinking and nutrition level did not change significantly. And the knowledge level for DM decreased. Conclusion: We expect that taking this case management program for DM management may significantly improve diabetic patients' overall health.

• 한국안전학회지
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• 제20권3호
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• pp.58-63
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• 2005

In this research, silicone rubber with additions of inorganic filler, alumina trihydrate$(Al(OH)_3\;:\;ATH)$, was aged acceleratedly and cyclically by the salt-fog and heating. The optimum amount of ATH addition to silicone rubber have been investigated by measurements of leakage current in the change of electrical properties and tensile strength, %elongation in mechanical properties and FT-IR, TG, SEM in the change of the chemical properties. With regard to un-aged silicone rubber, as the ATH addition amount increases, conductive path formation time was shortened in the electrical properties and tensile strength was increased, %elongation was decreased. In case of identical ATH addition amount, as cyclic aging increases, surface resistivity, tensile strength and %elongation were decreased. Considering the cyclic aging, the most effective amount of ATH addition was about 90phr.

• 한방재활의학과학회지
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• 제26권2호
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• pp.85-96
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• 2016

Objectives This study was performed to evaluate the effects of acupuncture, electro-acupuncture and acupuncture with pulsed electromagnetic therapy on upper extremity of healthy people and hemiplegic patients by D.I.T.I.. Methods 20 healthy people and 20 hemiplegic patients caused by stroke were selected. They have been treated three different types of treatment; acupuncture, electro-acupuncture and acupuncture with pulsed electromagnetic therapy. And skin temperature of upper extremity has been measured before and after each treatment by D.I.T.I.. The thermographic data was analyzed by 'Independent T-test' and 'Repeated measures ANOVA test'. Results 1. In healthy group, there was very statistical significant difference (p<0.001) of the amount of thermal change by each treatment, and the amount of change was arranged in descending order; acupuncture with pulsed electromagnetic, acupuncture and electro-acupuncture. 2. In hemiplegic group, the skin temperature of hemiplegic side was $0.97^{\circ}C$ cooler than non-hemiplegic side. 3. Skin temperature of all hemiplegic patients was increased after acupuncture treatment. 4. In hemiplegic group, there was statistical significant difference (p<0.05) of the amount of thermal change by each treatment, and the amount of change was arranged in descending order; acupuncture with pulsed electromagnetic, acupuncture and electro-acupuncture. Conclusions The results indicate that acupuncture, electro-acupuncture and acupuncture with pulsed electromagnetic therapy had good effect on the change of skin temperature by stimulating sympathetic nervous system.