• 한국세라믹학회지
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• 제49권5호
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• pp.454-460
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• 2012

The nano-sized zirconia powders were synthesized in an impregnation method using pulp and $ZrOCl_2{\cdot}8H_2O$ as an initial material. The synthesized powders were characterized by XRD and FE-SEM. The particle size of the powder was controlled by preparation conditions, such as drying temperature and time. As a result of the various drying and calcination conditions, 30~50 nm sized homogeneous zirconia particles were obtained at $800^{\circ}C$ for 1 h. Crystallization and the rapid growth of particles were accelerated with increasing calcination temperature and time. Tetragonal phase generated below $800^{\circ}C$ were transferred to monoclinic phase with increasing calcination temperature and time. Moreover, above $800^{\circ}C$, heat treatment time had very large influence on the particle growth, and the change of drying condition also had large influence on the growth of a crystal.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1817-1822
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• 1991

A method of reducing overhead caused by the processor synchronization process and common memory accesses in finely grained tasks is described. We propose a scheduler which considers the preparation time during searching to minimize the redundant accesses to shared memory. Since the suggested hardware (synchronizer) determines the access order of processors and bus arbitration simultaneously by including the synchronization process into the bus arbitration process, the synchronization time vanishes. Therefore this synchronizer has no overhead caused by the processor synchronization[l]. The proposed scheduler algorithm is processed in parallel. The processes share the upper bound derived by each searching and the lower bound function is built considering the preparation time in order to eliminate as many searches as possible. An application of the proposed method to a multi-DSP system to calculate inverse dynamics for robot arms, showed that the sampling time can be twice shorter than that of the conventional one.

• 대한가정학회지
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• 제25권2호
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• pp.79-87
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• 1987

Paeksolgi is a typical Korean rice cake made by steaming rice powder added sugar, water and salt. This study attempted to clarify the factors which affect the textural characteristics, and to examine the effects of various steaming time and volume of adding water on sensory characteristics and Instron measurement on textures of Paeksolgi. Evaluation was conducted through sensory evaluation and objective evaluation. The results were summarized as follows. 1. In the preparation, the significant factors were soaking time, volume of sugar, and the interaction between soaking time and volume of adding water. And, Kind of sweetener, volume of adding water, steaming time, condition of powder, and the interaction between soaking time and steaming time, and between soaking time and volume of adding water, and between kind of sweetener and condition of powder, and between steaming time and volume of sugar were the significant factors which affected the textural characteristics of Paeksolgi. 2. In sensory evaluation on the various steaming time and volume of adding water, Paeksolgi made by steaming rice powder added water of 10% for 30 min. showed the most favorite tendency on the overall quality. The results of Instron measurement indicated that hardness, gumminess and chewiness tended to decrease as volume of adding water increased in same steaming time.

• Restorative Dentistry and Endodontics
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• 제26권5호
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• pp.418-435
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• 2001

Root canal preparation process is of utmost importance in successful treatment of root canal. Also, one of the most important purpose of the root canal preparation is to enlarge the root canal three dimensionally without changing the curvature of the root canal However as the curvature of the root canal increases, there are many difficulties involved in formation of optimum root canal. Therefore in order to solve the above mentioned problems, new developments in methods of root canal preparation and equipments for such purposes were made. Recently, vigorous studies about newly introduced engine-driven nickel-ti-tanium rotary file are conducted. As shown in research results to dates, it is well established that the use of nickel-titanium file is better suited for curved root canal than stainless steel file in maintaining the curvature or root canal and reducing the deformation of root canal. However it is also acknowledged that there are a few discrepancies in research results according to protocol, due to failure to remove variables in experiments. In addition, although it is recommended by the manufacturer that the GT rotary file should maintain a low rotational speed of 150~350rpm and 'light pressure' as light as not to break the lead of a pencil, academic studies about the vertical force which is not yet standardized are not sufficiently explored. Therefore, this research devised and utilized a special research equipment to standardize the appropriate range of vertical force for GT rotary file through experiments by breaking of the lead of a pencil as expressed by the manufacturer and to accurately measure factors involved through repeating and recreating the environment of root canal preparation. Forming nine experimental groups by varying the vertical forces (150g. 220g, 300g) and rpm (150rpm, 250rpm, 350rpm), the effects of changing vertical forces and rpm on working efficiency were measured in terms of time expended in root canal preparation by crown-down method using a transparent resin block with 35 degree curvature and GT rotary file (z-test). The following research using this special research equipment that involved nine experimental groups and varying the vertical force for root canal preparation from 300g which is within the normal vertical force range to 700g and 1000g which fall outside the normal rpm range. The results were as follows : 1. Analysis of the experiment results revealed that the time spent in root canal preparation decreased as the vertical forces and rpm increased (p<0.05). Also, the effects of rpm were greater than those of the vertical forces within the normal vertical force range ($\beta$-weight test). 2. Observation of the deformation of GT rotary file revealed that deformation increases in a direct correlation with the vertical force increase and in a reverse correlation with the rpm decrease. In the case of the vertical forces close to the normal range, the probability of GT rotary file deformation were quite different depending on the rpm changes. In the case of greater vertical forces, the occurrences of deformation of the file were more frequent regardless of the rpm changes. 3. Deformation and breakage of file were also commonly observed in the expended time measurement experiments and GT rotary file deformation experiments in which low speed rpm (150rpm) was used and at the curved portion of the resin block.

• 한국지역사회생활과학회지
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• 제21권3호
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• pp.411-425
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• 2010

The purpose of this study is to examine the middle aged social preparation for later life and to explore the effect of social activities and social relationships on social preparation for later life. This research is also focused on gender differences in social activities, social relationships and social preparation for later life. The survey data was gathered from 424 middle aged citizens who live in the Gwangju & Jeonnam area, using a structured questionnaire. The statistical methods used for data analysis were descriptive statistics, cross tables, t-test, correlations, and hierarchical regression with SPSS win 18.0 program. The major findings of this study are as follows: Most of the respondents perceive an importance of social activities and social relationships. Middle aged women enjoy leisure activities such as learning and religious activity more than men. Middle aged men engage in hobby activities more than women. And most of respondents perceive they are making an effort to keep a relationship with spouses, family & friends. The results show that there are no differences in social preparation for later life between gender groups, but the variables which have an effect in social preparation for later life are different between gender groups. Social activities and Social relationships play an important role in social preparation for later life of Middle aged men and women. At the same time, Social activities and Social relationships have more positive effect on the social preparation of women. Implications of the results are discussed.

• 한국식품조리과학회지
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• 제11권5호
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• pp.557-564
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• 1995

This study was attempted to standardize preparation methods of Korean foods; Pibimbab (mixed rice) and Kongnamul Pibimbab (sprout mixed rice with soybean). We followed cooking method by using cookbooks, food service operation recipes , materials distributed by commercial food restaurants from their own experimental kitchens, and home recipes. Before those recipes were standardized, we thoroughly analyzed and modified. The total yield and portions were determined together with weights and procedures. And we evaluated food made by standardized recipes for acceptability by taste panels from Sookmyung Women's University. It concluded that yield volume for Pibimbab and Kongnamul Pibimbab after cooking for 10 persons was 6.5 kg, optimum service temperature was 7$0^{\circ}C$, preparation time was 6 hours, service volumes by one person was 650 g. This presentation for above on food materials and material weights, preparation methodsas well as cautions and references are attached in this research paper.

• 한국식품조리과학회지
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• 제11권3호
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• pp.220-225
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• 1995

This study was attempted to standardize preparation methods of Korean foods; Chigae (Stew) such as Deonjang chigae (soybean stew) and Kimchi chigae (Kimchi stew). We followed cooking methods by using cookbooks, food service operation recipes, materials distributed by commercial food restaurants from their own experimental kitchens, and home recipes. Before this recipes were standardized, we thoroughly analyzed and modified them. The total yield and portions were determined together with material weights and procedures. And we evaluated food made by standardized recipes for acceptability, by taste panels from Sookmyung Women＇s University. It concluded that yield volune for doenjang chigae and kimchi chigae after cooking for 10 persons was 3 kg, optimum service temperature was 7$0^{\circ}C$, preparation time was 50 minutes, service volumes by one person was 300 g. This presentantion for the above on food materials and material weights, preparation methods as well as cautions and references are attached in this research paper.

• 약학회지
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• 제47권3호
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• pp.154-158
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• 2003

Lincomycin, a selective tyrosinase blocker, has been thought to be effective in the treatment of melanogenesis, ephelis, post inflammatory pigmentation, and facial discoloration. In an attempt to develop a transdermal perparation for lincomycin, this study was designed to examine the appropriate contents of various surfactants and ethanol in the cream preparation. Frans type diffusion cell was used to investigate permeation efficiency of the preparation, and lincomycin in the receptor phase was measured by HPLC. After having a 1.5 hrs of leg time, the permeability of lincomycin was rapidly increased by adding surfactants, and varied with different types of surfactants after 10 hrs, the permeability of Brij 56$^{(R)}$ preparation (501.4$\pm$45 $\mu\textrm{g}$/mι) was greater than that either of Labrasol$^{(R)}$ (263.9$\pm$33.7 $\mu\textrm{g}$/mι) or Tween$^{(R)}$20(386.2$\pm$26.7 $\mu\textrm{g}$/mι). Ethanol also increased the permeability of lincomycin.mycin.

• Mass Spectrometry Letters
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• 제15권1호
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• pp.62-68
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• 2024

The Suspension Trapping (S-Trap) method has been a prominent sample preparation technique since its introduction in 2014. Its capacity to induce protein aggregation using organic solvents has significantly improved protein purification and facilitated peptide identification. However, its full potential for automation has been limited by the lack of a suitable liquid handling system until recently. In this study, we aimed to enhance the automation of S-Trap sample preparation by optimizing the S-Trap digestion process, incorporating triethylammonium bicarbonate (TEAB) and CaCl₂. The utilization of TEAB buffer conditions in this innovative process led to a noteworthy 12% improvement in protein identification. Additionally, through careful observation of various incubation conditions, we streamlined the entire sample preparation workflow into a concise 4 hours timeline, covering reduction, alkylation, and trypsin incubation stages. This refined and expedited automated S-Trap digestion process not only showcased exceptional time efficiency but also improved trypsin digestion, resulting in increased protein identification.

• 의학교육논단
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• 제23권3호
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• pp.168-175
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• 2021

To analyze medical professors' evaluation of their online education experiences in an attempt to support faculty members and indicate the future direction of medical education. Faculty members who taught online in the first semester of 2020 at Yonsei University College of Medicine in South Korea were surveyed. The results of the survey were analyzed in June 2020. There were 88 respondents (35.1% of 251): 59 professors (67.0%), 16 associate professors (18.2%), and 13 assistant professors (14.8%). Their specialties lay in basic medicine (25.0%), clinical medicine (65.9%), and research and special purposes (9.1%). Sixteen participants (18.2%) had previous experience in online lectures; 23 (26.1%) reported that preparation time for online lectures was the same as before; 65 (73.9%) reported that the preparation time had increased; 38 (43.2%) faced difficulties in preparation and lecturing online, and among them 16 (42.1%) indicated inadequate interaction with students; 11 (28.9%) needed extra preparation time; and 11 (28.9%) attributed their difficulties to technical issues with the online platform. Participants' satisfaction with online lectures was low (p<0.001). In the free response question on overall experience with online education, 38.3% mentioned the need for an instructional design that allows students to actively participate and interact with professors, 29.5% mentioned the need for the establishment of an information & communications technology system, and 17.0% mentioned the necessity of faculty development. To prepare for the current pandemic and more in the long term, an appropriate educational support system must be constructed, and a learner-centered instructional design that enables wider interactions and active learning is needed.