• Journal of dental hygiene science
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• v.12 no.6
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• pp.624-633
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• 2012

This study was executed to provide the basic data that can be helpful for a program aiming at the enhancement of life quality or establishment of policy related to public health by analyzing the importance of health state among the middle-aged adults when it came to the decision of life quality. For 160 adults who were older than 40 years old, a survey was conducted and the results were derived by using t-test, one way ANOVA, and multiple regression analysis. Followings are the outcome of the study. According to such results, it was known that the level of general life quality and oral health related life quality were shown to be different depending on symptoms of depression and xerostomia. Therefore, it suggests that prevention and early intervention of depression and xerostomia will make a great contribution to improve the life quality among the middle-aged adults.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.1
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• pp.29-34
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• 2021

Near infrared reflectance spectroscopy (NIRS) is routinely used for the determination of nutrient components of forages. However, little is known about the impact of sample preparation and wavelength on the accuracy of the calibration to predict minerals. This study was conducted to assess the effect of sample preparation and wavelength of near infrared spectrum for the improvement of calibration and prediction accuracy of Calcium (Ca) and Phosphorus (P) in imported hay using NIRS. The samples were scanned in reflectance in a monochromator instrument (680-2,500 nm). Calibration models (n = 126) were developed using partial least squares regression (PLS) based on cross-validation. The optimum calibrations were selected based on the highest coefficients of determination in cross validation (R2) and the lowest standard error of cross-validation (SECV). The highest R2 and the lowest SECV were obtained using oven-dry grinded sample preparation and 1,100-2,500 nm wavelength. The calibration (R2) and SECV were 0.99 (SECV: 468.6) for Ca and 0.91 (SECV: 224.7) for P in mg/kg DM on a dry weight, respectively. Results of this experiment showed the possibility of NIRS method to predict mineral (Ca and P) concentration of imported hay in Korea for routine analysis method to evaluate the feed value.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.389-396
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• 2014

Purpose: The study examined dry eye symptoms of occupants in a newly constructed building and its effects on their work productivity and general activity. Methods: The study subjects were 33 office workers who spent more than eight hours per day on average in a new building constructed in the past three months. The indoor air quality of the new building was evaluated by measuring aldehydes, temperature and humidity. The level of dry eye symptoms was classified into normal, mild, moderate and severe by using the Ocular Surface Disease Index (OSDI). The experience of LASIK surgery, use of eye makeup, daily use time of a computer and smart-phone, and average daily working hours were also examined. The Work Limitation Productivity Questionnaire was used as the questionnaire about work productivity and general activity to measure the impairment level on a ten-point scale. Results: The concentration variation of formaldehyde in the office was $42.42{\pm}6.30{\mu}g/m^3$. The temperature and humidity were $26.2{\pm}0.70^{\circ}C$ and $40{\pm}1%$, respectively. The respondents with normal, mild, moderate and severe dry eye symptoms were 15.2%, 18.2%, 18.2% and 48.5%, respectively. The severity of dry eye symptoms and impairment of work productivity and general activity demonstrated high correlations of 0.599 and 0.655, respectively (p<0.001). Compared to the normal case, severe dry eye symptoms demonstrated significantly high impairment of work productivity and interruption of general activity (p<0.001). The case of serious dry symptoms showed the possibilities of having impairment level of work productivity and interruption of general activity above three points 3.26 times (p=0.032) and 2.25 times (p=0.045), respectively, higher than that of the normal case. Conclusions: It was confirmed that dry eye symptoms among office workers in a newly constructed building affects work productivity and general activity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1921-1927
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• 2009

In this paper, a point-to-multipoint wireless communication system based on Bluetooth specifications, which is possibly applied to very large vessels, is implemented and analyzed. Here, a communication network is composed of a slave Bluetooth module connected to the task computer and multiple master Bluetooth modules equipped with a sensor. And exploiting the point-to-multipoint data communication among the Bluetooth modules, a surveillance system that recognizes and controls a variety of emergency situations happened on a large vessel is implemented. It is, therefore, considered that the wireless communication system implemented in this paper is possibly exploited a basic technology for the digital shipbuilding of the next generation.

• Culinary science and hospitality research
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• v.7 no.3
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• pp.35-44
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• 2001

Kimchi aged for 10-15 days at 1$0^{\circ}C$ was freeze dried to make soup. Flour was roasted to make roux for 2 hr. at 17$0^{\circ}C$, and the roasted flour was mixed with butter, beef and various seasonings like ginger garlic. Materials containing much moisture were roasted to eliminate water and used for soup preparation. Freeze-dried kimchi was added with 10%, 20% and 30%, respectively. The control kimchi soup was a little affected by butter flavor and the kimchi soup made by adding 20% of freeze-dried kimchi powder showed the best acceptability in quality description analysis.

• The Journal of Engineering Research
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• v.4 no.1
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• pp.87-91
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• 2002

Nano-size Alumina powders were prepared by heat treatments which were products obtained using supercritical drying and fluid method. Al-isopropoxide dispersed in ethylene glycol as solvents were used as starting materials. The alumina powders were made by supercritical drying fluid method at Autoclave, those were characterize examined closely by XRD, SEM and TG-DTA. The powders were transformed $\alpha-A12O3$ in new route after heat treatment.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.342-349
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• 1982

Filefish muscle in the form of thin plate $(5{\times}10{\times}0.4\;cm)$ was dried in a forced air dryer at $47.5^{\circ}C$ to study the relation between dehydration mechanism and water activity. The dryer was designed in such a way that the temperature, relative humidity and velocity of air could be controlled. The whole dehydration process of the filefish muscle was divided into two different drying rate periods, constant and falling rate period. During the constant drying rate period, the drying rate was proportional to the square root of air velocity under the conditions of constant temperature and relative humidity of air. The falling rate period was further divided into two different falling drying rate periods, first and second falling rate period. The first falling rate period was an unsaturated surface drying period caused by partial unsaturation of the drying surface with capillary condensed free water diffused from the internal part of the filefish muscle. At this stage he drying rate was mainly dependent on the relative humidity at constant air temperature, and case-hardening phenomenon started at the end of this stage. The moisture content and the water activity at which the second falling rate period started were not constant, because the drying rate of the first falling rate period was strongly dependent on the air humidity. The second falling rate period was again divided into two drying rate periods, former and latter period. The drying rates of both of these periods were independent on the external air humidity. During the former period of the second falling rate period, the dehydration was proceeded by diffusion and vaporization of capillary condensed free water in filefish muscle. The diffusion coefficient of water was $2.89{\times}10^{-10}m^2/sec\;at\;47.5^{\circ}C$. At this stage, the case-herdening continued until the water activity reduced to 0.7. The latter period of the second falling rate period started at the water activity of 0.45. The dedydration was proceeded by diffusion and vaporization of bound water, which adsorbed in multimolecular layers, through the hardened drying surface. The number of molecular layers was 4, and the diffusion coefficient of water during this stage was $4.38{\times}10^{-11}m^2/sec\;at\;47.5^{\circ}C$.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.189-194
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• 2001

A simultaneous visualization of the behavior of bubbles and dry spots has been carried out for pool boiling of R-1l3 on a horizontal heater. From video imaging and image processing analysis, the formation of bubbles and dry spots occurs simultaneously, and therefore they should be considered as a synchronized concept rather than independent identities. The dry spot density is equivalent to the active site density in the region before CHF. At CHF point, large dry areas due to the coalescence of neighboring dry areas cover the heater surface.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.22-24
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• 2007

최근 소형선박의 선체 재료로써 기존의 FRP선이 갖는 환경문제와 자원의 재활용 및 선체중량경감의 측면에서 소형선박을 중심으로 알루미늄선으로의 전환이 이루어져 왔지만, 알루미늄에 대한 용접 기능공 및 기술이 부족하여 건조 공정에 많은 시간과 비용이 소요되어 중소조선소에선 알루미늄선체 건조에 많은 애로 점을 가지고 있다. 이에, 본 연구를 통해 알루미늄선체의 구조부재 제작시 용접에 의한 공정을 압출성형 기법으로 대체하고 알루미늄선체의 용접에 소요되는 높은 인건비와 시간을 절약하여 원가 절감의 효과를 도모하며 또한 알루미늄선박 일체형 구조부재의 경량화 기법과 한국선급의 알루미늄선체 강도 기준을 적용하여 표준화된 구조부재의 압출성형 기법을 정립하고자 한다.

• The tire
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• s.69
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• pp.12-16
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• 1977

타이어의 실노면상에서의 트랙션성능을 측정, 평가하는것은 자동차의 발진, 가속, 제동 및 시회성능의 점으로브터 중요하면 이것을 측정하기 위해서 타이어 트랙션시험차를 개발했다. 이시험차는 타이어의트랙션성능을 미끄럼율과제동, 구동계수의 관계, 횡화각과 사이드포오스계수, 어라이닝토루크의 관계로 측정되는 특장을 갖는다. 이시험차를 이용해서, 건조및 습윤아스팔트노상과 설노상에서의 트랙션성능에 대한 타이어트랫드의 기본적 페턴의영향을 측정한 결과, 다음과 같은 지견을 얻었다. (1)도로의 상태의 상위에 의한 타이어트랙션 성능은 건조상태에선 습윤상태보다 크며 노설상에선 전양자보다 훨씬 작다. (2)트랫드의 종방향의 구본수의 영향에 대해선 여하한 노면상태에서든 구본수가 증가한만큼 트랙션성능은 증가하나 어느구본수에선 포화하는 경향이 있다. (3)설노상에서의 트랫드의 구각도에 대해서는 구의각도가 타이어의 진행방향에 대해서 직각의 페턴이 좋다고 할 수 있다.