• Title/Summary/Keyword: 과학작업

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Esthetic restoration of maxillary anterior teeth considering facial features in digital diagnostic wax-up: a case report (디지털 진단 왁스업을 통하여 안모를 고려한 상악 전치부 심미수복 증례)

  • Sung-Ji Gong;Sang-Won Park;Hyun-Pil Lim;Kwi-dug Yun;Chan Park;Woohyung Jang
    • Journal of Dental Rehabilitation and Applied Science
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    • v.40 no.3
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    • pp.179-188
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    • 2024
  • To enhance the predictability of aesthetic treatment outcomes in aesthetic prosthetic restorations, considerations must include analysis of facial features, the relationship between teeth and lips, proportions of tooth width/length, gingival form, and more. Traditional diagnostic wax-ups have limitations in considering the patient's facial features and are unable to facilitate rapid form modifications. With recent advancements in digital technology, it is now possible to digitize the patient's facial features in three dimensions, enabling the design of restorations that harmonize with facial features. These digital workflows not only improve efficiency but also provide patients with faster visualization of treatment outcomes, thereby enhancing motivation. Therefore, in this case, a treatment plan is devised to utilize digital diagnostic wax-ups considering the patient's facial features for the final prosthetic design.

A Review of the Neurocognitive Mechanisms for Mathematical Thinking Ability (수학적 사고력에 관한 인지신경학적 연구 개관)

  • Kim, Yon Mi
    • Korean Journal of Cognitive Science
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    • v.27 no.2
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    • pp.159-219
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    • 2016
  • Mathematical ability is important for academic achievement and technological renovations in the STEM disciplines. This study concentrated on the relationship between neural basis of mathematical cognition and its mechanisms. These cognitive functions include domain specific abilities such as numerical skills and visuospatial abilities, as well as domain general abilities which include language, long term memory, and working memory capacity. Individuals can perform higher cognitive functions such as abstract thinking and reasoning based on these basic cognitive functions. The next topic covered in this study is about individual differences in mathematical abilities. Neural efficiency theory was incorporated in this study to view mathematical talent. According to the theory, a person with mathematical talent uses his or her brain more efficiently than the effortful endeavour of the average human being. Mathematically gifted students show different brain activities when compared to average students. Interhemispheric and intrahemispheric connectivities are enhanced in those students, particularly in the right brain along fronto-parietal longitudinal fasciculus. The third topic deals with growth and development in mathematical capacity. As individuals mature, practice mathematical skills, and gain knowledge, such changes are reflected in cortical activation, which include changes in the activation level, redistribution, and reorganization in the supporting cortex. Among these, reorganization can be related to neural plasticity. Neural plasticity was observed in professional mathematicians and children with mathematical learning disabilities. Last topic is about mathematical creativity viewed from Neural Darwinism. When the brain is faced with a novel problem, it needs to collect all of the necessary concepts(knowledge) from long term memory, make multitudes of connections, and test which ones have the highest probability in helping solve the unusual problem. Having followed the above brain modifying steps, once the brain finally finds the correct response to the novel problem, the final response comes as a form of inspiration. For a novice, the first step of acquisition of knowledge structure is the most important. However, as expertise increases, the latter two stages of making connections and selection become more important.

Development of a Small Size Hammer Mill for Farm Use (I) (농가용(農家用) 소형(小型) 사료(飼料) 분쇄기(粉碎機) 개량(改良)에 관(關)한 연구(硏究) (I))

  • Chang, D.I.;Kim, S.R.;Kim, M.S.;Lee, B.D.;Yi, K.J.
    • Korean Journal of Agricultural Science
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    • v.10 no.2
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    • pp.334-344
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    • 1983
  • This study was conducted to investigate the variables affecting the performance of hammer mills by the theoretical and dimensional analysis, and evaluate the power requirements of hammer mills for farm use in Korea. From the theoretical analysis, 16 variables affecting the performance of hammer mills were defined. In order to develop the mathematical relationships among the variables, the dimensional analysis was made for power requirements and $12{\pi}$ parameters were obtained. For the evaluation of the power requirements of hammer mills, approximate rates of grinding for 1HP, 3HP, 5HP, 6HP, 8HP, and 10HP were analyzed. Then, the fineness of grinding recommendation and average feeding rate of grain for livestock which is native cattle, dairy cattle, beef cattle, swine, broilers, and layers, were estimated. Finally number of livestock feeding shelled corn and barley were estimated from the above for one hour's hammer mill operation having the various power requirements. From this study it is known that 5HP is considered as an enough power for feed grinding of any kinds of livestock of Korean farm, as far as the grinding capacity is concerned.

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Characteristics of Percutaneous Absorption of Glycol ethers (Glycol ethers에 대한 피부 투과 특성)

  • Lee, Han-Seob;Choi, Sung-Boo;Kim, Nac-Joo;Keun, Jang-Hyoun;Hwang, Hyun-Suk;Baek, Jung-Hun;Choi, Jin-Ho;Lee, Ho-Joon
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.116-126
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    • 2013
  • Glycol ethers are a group of solvents based on alkyl ethers of ethylene glycol commonly used in paints. These solvents typically have a higher boiling point, together with the favorable solvent properties of lower-molecular weight ethers and alcohols. The word "Glycol ethers" was registered as a United States trademark by Union Carbide Corp. Typically, glycol ethers are found in pharmaceuticals, sunscreens, cosmetics, inks, dyes and water based paints. On the other hand, glycol ethers are used in degreasers, cleaners, aerosol paints and adhesives. Most glycol ethers are relatively water soluble, biodegradable and only a few are considered toxic. Therefore, they are unlikely to pose an adverse risk to the environment. Recent study suggests that occupational exposure to glycol ethers is related to low motile sperm count in men, but the finding has been disputed by others. In this study, skin permeation of 3 types glycol ethers were studied in vitro using matrix such as solvent and detergent. The absorption of glycol ethers[methyl glycol ethers(MC), ethyl glycol ethers(EC) and butyl glycol ethers(BC)] has been measured in vitro through rat skin. Epidermal membranes were set up in Franz diffusion cells and their permeability to PBS measured to establish the integrity of the skin before the glycol ethers were applied to the epidermal surface. Absorption rates for each glycol ethers were determined and permeability assessment made to quantify any irreversible alterations in barrier function due to contact with the esters. Types of glycol ethers in vitro experimental results on MC> EC> BC quickly appeared in the following order: skin permeation was beneficial to the skin permeation small molecular weight, the difference in chemical structure, such as hydrophilic, because with the partition coefficient and solubility mechanisms and passive diffusion to increase the speed at which transmission is considered.

Study about porous of Korean traditional pottery (한국전통옹기의 통기성에 관한연구)

  • Kim, Seok-Ho
    • Journal of Science of Art and Design
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    • v.9
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    • pp.5-24
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    • 2006
  • Human hunted and picked to survive and a vessel was made naturally to store something being hunted and picket, which was a great invention. In modern times, society changed and development of science gave us convenience in making a vessel and various kinds of store instruments which was made of pure natural material, of new stuff, such as plastic and iron. but human became to be inclined to regress into nature because of problems of environment. We can say that the representative trend is well-being, after all this is a symptom to return to life being persued by predecessors before the science civilization was developed. Ancestors have lived with nature, adapted themselves to it. For examples they have built the house which became to be a part of nature and just like it, and studied a method of storing food to eat for four seasons, then displayed a storagehouse and storage containers everywhere of the house. Now Korean has the custody of kimchi in refrigerator at every house, but our forefathers controled a timing to eat food with studying a method of storage to put to use nature. With hot wind of well-being, Korean food is becoming to be globalized, according to this, concern about the wisdom of progenitors is growing more and more. It's an example that the world shows concern seriously about the pottery, which have stored kimchi for a long time fleshly, in globalization of kimchi. This study have three purposes, the first. checking documents about the development history of pottery which is a kind of ceramic, and then the second, through an scientific experiment, with studying characteristic of pottery being built by the wisdom of ancestors, informing the merit of pottery and necessity to the world, and futhermore, the third, working up the development of close environmental vessels putting to use the characteristic of pottery.

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Distribution and Natural Regeneration of Abies holophylla in Plantations in Gapyeong, Gyeonggi-do (경기도 가평 지역 조림지 내 전나무(Abies holophylla)의 분포와 천연갱신)

  • Nam, Kwanghyun;Joo, Kwang Young;Choi, Eun Ho;Jung, Jong Bin;Park, Pil Sun
    • Journal of Korean Society of Forest Science
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    • v.110 no.3
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    • pp.341-354
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    • 2021
  • A large part of Gapyeong is occupied by Korean pine (Pinus koraiensis) and Japanese larch (Larix kaempferi) plantations. Abies holophylla stands are scattered throughout Gapyeong, but little information on their distribution is available. This study explored the potential of succession from planted species to native A. holophylla in plantations. Trees were inventoried and regeneration of A. holoplhylla and stand management history were examined in Korean pine, Japanese larch, and A. holophylla-dominated stands. The importance percentage of A. holophylla was the highest among species with a range of 36.1% to 79.1% in all stands and the density of A. holophylla in understory (DBH <2 cm or <1.3 m height) ranged from 50 to 5,820 trees ha-1. Non-metric multidimensional scaling classified stands into four types, AN, AP, AM, and P. The AN type showed a reverse J-shape DBH distribution, which was similar to that in natural A. holophylla stands. Both AP and AM types included Korean pine plantations with A. holophylla seed trees within stands. For AP, A. holophylla competed with planted species in overstory and deciduous broadleaved species in understory. The AM type was once thinned from below, thus stem density in the mid DBH classes was lower than upper or lower DBH classes. The P type consisted of plantations without A. holophylla seed trees. However, understory regeneration of A. holophylla was abundant through seed supply from A. holophylla in adjacent stands. Plantations with A. holophylla seed trees within or in adjacent stands showed vigorous natural regeneration of A. holophylla, highlighting the potential for succession from planted species to native A. holophylla in the Gapyeong area. Further studies can help develop techniques to restore plantations to native species-dominated natural stands using ecological succession.

Optimal Operation of Gas Engine for Biogas Plant in Sewage Treatment Plant (하수처리장 바이오가스 플랜트의 가스엔진 최적 운영 방안)

  • Kim, Gill Jung;Kim, Lae Hyun
    • Journal of Energy Engineering
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    • v.28 no.2
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    • pp.18-35
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    • 2019
  • The Korea District Heating Corporation operates a gas engine generator with a capacity of $4500m^3 /day$ of biogas generated from the sewage treatment plant of the Nanji Water Recycling Center and 1,500 kW. However, the actual operation experience of the biogas power plant is insufficient, and due to lack of accumulated technology and know-how, frequent breakdown and stoppage of the gas engine causes a lot of economic loss. Therefore, it is necessary to prepare technical fundamental measures for stable operation of the power plant In this study, a series of process problems of the gas engine plant using the biogas generated in the sewage treatment plant of the Nanji Water Recovery Center were identified and the optimization of the actual operation was made by minimizing the problems in each step. In order to purify the gas, which is the main cause of the failure stop, the conditions for establishing the quality standard of the adsorption capacity of the activated carbon were established through the analysis of the components and the adsorption test for the active carbon being used at present. In addition, the system was applied to actual operation by applying standards for replacement cycle of activated carbon to minimize impurities, strengthening measurement period of hydrogen sulfide, localization of activated carbon, and strengthening and improving the operation standards of the plant. As a result, the operating performance of gas engine # 1 was increased by 530% and the operation of the second engine was increased by 250%. In addition, improvement of vent line equipment has reduced work process and increased normal operation time and operation rate. In terms of economic efficiency, it also showed a sales increase of KRW 77,000 / year. By applying the strengthening and improvement measures of operating standards, it is possible to reduce the stoppage of the biogas plant, increase the utilization rate, It is judged to be an operational plan.

A Systematic Review of Developmental Coordination Disorders in South Korea: Evaluation and Intervention (국내의 발달성협응장애(DCD) 연구에 관한 체계적 고찰 : 평가와 중재접근 중심으로)

  • Kim, Min Joo;Choi, Jeong-Sil
    • The Journal of Korean Academy of Sensory Integration
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    • v.19 no.1
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    • pp.69-82
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    • 2021
  • Objective : This recent work intended to provide basic information for researchers and practitioners related to occupational therapy about Developmental Coordination Disorder (DCD) in South Korea. The previous research of screening DCD and the effects of intervention programs were reviewed. Methods : Peer-reviewed papers relating to DCD and published in Korea from January 1990 to December 2020 were systematically reviewed. The search terms "developmental coordination disorder," "development coordination," and "developmental coordination" were used to identify previous Korean research in this area from three representation database, the Research Information Sharing Service, Korean Studies Information Service System, and Google Scholar. We found a total of 4,878 articles identified through the three search engines and selected seventeen articles for analysis after removing those that corresponded to the overlapping or exclusion criteria. We adopted "the conceptual model" to analyze the selected articles about DCD assessment and intervention. Results : We found that twelve of the 17 studies showed the qualitative level of Level 2 using non-randomized approach between the two groups. The Movement Assessment Battery for Children and its second edition were the most frequently used tools in assessing children for DCD. Among the intervention studies, the eight articles (47%) were adopted a dynamic systems approach; a normative functional skill framework and cognitive neuroscience were each used in 18% of the pieces; and 11% of the articles were applied neurodevelopmental theory. Only one article was used a combination approach of normative functional skill and general abilities. These papers were mainly focused on the movement characteristics of children with DCD and the intervention effect of exercise or sports programs. Conclusion : Most of the reviewed studies investigated the movement characteristics of DCD or explore the effectiveness of particular intervention programs. In the future, it would be useful to investigate the feasibility of different assessment tools and to establish the effectiveness of various interventions used in rehabilitation for better motor performance in children with DCD.

Analysis of Munitions Contract Work Using Process Mining (프로세스 마이닝을 이용한 군수품 계약업무 분석 : 공군 군수사 계약업무를 중심으로)

  • Joo, Yong Seon;Kim, Su Hwan
    • Journal of Intelligence and Information Systems
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    • v.28 no.4
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    • pp.41-59
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    • 2022
  • The timely procurement of military supplies is essential to maintain the military's operational capabilities, and contract work is the first step toward timely procurement. In addition, rapid signing of a contract enables consumers to set a leisurely delivery date and increases the possibility of budget execution, so it is essential to improve the contract process to prevent early execution of the budget and transfer or disuse. Recently, research using big data has been actively conducted in various fields, and process analysis using big data and process mining, an improvement technique, are also widely used in the private sector. However, the analysis of contract work in the military is limited to the level of individual analysis such as identifying the cause of each problem case of budget transfer and disuse contracts using the experience and fragmentary information of the person in charge. In order to improve the contract process, this study analyzed using the process mining technique with data on a total of 560 contract tasks directly contracted by the Department of Finance of the Air Force Logistics Command for about one year from November 2019. Process maps were derived by synthesizing distributed data, and process flow, execution time analysis, bottleneck analysis, and additional detailed analysis were conducted. As a result of the analysis, it was found that review/modification occurred repeatedly after request in a number of contracts. Repeated reviews/modifications have a significant impact on the delay in the number of days to complete the cost calculation, which has also been clearly revealed through bottleneck visualization. Review/modification occurs in more than 60% of the top 5 departments with many contract requests, and it usually occurs in the first half of the year when requests are concentrated, which means that a thorough review is required before requesting contracts from the required departments. In addition, the contract work of the Department of Finance was carried out in accordance with the procedures according to laws and regulations, but it was found that it was necessary to adjust the order of some tasks. This study is the first case of using process mining for the analysis of contract work in the military. Based on this, if further research is conducted to apply process mining to various tasks in the military, it is expected that the efficiency of various tasks can be derived.

Effects of Thermotherapy for Life Care in the Elderly with Chronic Neck Pain (만성 목통증 노인환자의 라이프케어를 위한 온열치료의 효과 연구)

  • Lee, Jong-Min;Shin, Ho-Jin;Kim, Sung-Hyeon;Roh, Young-Chae;Jung, Kyoung-Sim;Hahm, Suk-Chan;Lee, Sung-Jae
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.8
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    • pp.635-645
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    • 2019
  • Non-specific chronic neck pain (CNP) is a prevalent disorder and often accompany with pain, fatigue, reduced range of motion (ROM), and hand function. Although various types of drug are commonly used to manage the symptoms following CNP, there is a need for therapeutic exercise and alternative medicine interventions that have few side effects or are easy to apply. Present study investigated the effects of salt pack and neck exercise for life care of the elderly with non-specific CNP. Sixteen patients with non-specific CNP were recruited and randomly assigned into two groups: the intervention group (n=8) or the control group (n=8). All patients performed neck self-exercise for 30 min/day, 5 times a week for 1 week. And the subjects in the intervention group additionally received salt hot pack for 20 min per session. Visual analogue scale (VAS) and pain pressure threshold (PPT) using algometer were used to assess pain intensity (primary outcome). ROM of shoulder joint and grip strength were measured to test shoulder and hand function (secondary outcome). There were significant improvements in the intervention group (p<.05), while the subjects in the control group did not show a significant change after intervention (p>.05). Also, the intervention group show significant differences in VAS and PPT compared to the control group (p<.05). Thus, our results demonstrated that salt pack and neck exercise have a positive effect for life care in elderly patients with non-specific CNP.