• 한국대기환경학회지
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• 제8권4호
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• pp.262-268
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• 1992

The trend of international concerns on environmental conservation and domestic demand of ambient air quality improvement, specially on sulfur dioxide level has resulted in the establishment of mid-term strategy of environmental improvement and stepwise strengthening of emission regulations in this decade in Korea. Development of flue gas desulfurization(FGD) process is becoming an essential task to be accomplished especially for the power plants and large industrial facilities. This study is an initial stage researc focusing on the mass transfer principles in wet type FGD process and the effects of operating variables of a jet bubbling scrubber utilizing limestone slurry on sulfur dioxide removal efficiency. Experimental results showed this type of scrubbing system has some advantages in terms of mass transfer mechanism and removal efficiency. More rigorous research is needed for the reaction system and the comparison with existing FGD processess for the possible development of a process which is compatative in view of installation cost and treatment of by-products.

• 교통기술과정책
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• 제9권1호
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• pp.49-55
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• 2012

• 한국진공학회:학술대회논문집
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• 한국진공학회 2003년도 제24회 학술발표회 초록집
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• pp.157-157
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• 2003

• 대한가정학회지
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• 제26권3호
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• pp.153-169
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• 1988

This study aimed at investigating the socialization of householdwork to the difference of life style pattern of housewives. For the purpose, questionnaires were administrated to the housewives in Seoul and to analyse of the date, factor analysis F-test, t-test and path analysis were used. The results can be summarized as follows ; 1. By utilizing factor analysis, the life style patterns of housewives were classified into 7 types, they were named, self-improvement type, social activity type, modernistic type, sound and thrifty type, variety-seeking type, passive stability-seeking type, the traditional and conservative type. And the patterns of life style differed significantly according to all of the demographic variables except family type. 2. The level of socialization of householdwork was not reaching the medium, and the mean was 19.45. 3. The socialization of householdwork were influenced indirectly by the age, educational level, income level, family type and social activity type, variety seeking type, traditional and conservative type of the life style pattern. And directly, the age and educational level influenced the socialization of householdwork.

• 호남수학학술지
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• 제41권4호
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• pp.745-756
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• 2019

In this paper, we establish the log convexity and Turán type inequalities of extended (p, q)-beta functions. Likewise, we present the log-convexity, the monotonicity and Turán type inequalities for extended (p, q)-confluent hypergeometric function by utilizing the inequalities of extended (p, q)-beta functions.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.157-163
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• 2006

A new technique utilizing LII signal for the measurement of flow velocities of laminar diffusion flames has been investigated. Soot particles in ethylene diffusion flames are heated by a modulated Ar-ion laser beam. LII signals and their phase angles are measured using a lock-in amplifier at the different flame heights and the axial flow velocity are obtained from the measured phase angle delay. The measured velocities are similar to those from LDV measurements under the same operating conditions. The effects of laser power, LII signal wavelength, and modulation frequency are not sensitive to the velocity measurement. However, the choice of an optical chopper blade type could affect the measurement result. The use of a 6/5 chopper blade showed the better result that is possibly due to the square shape of modulated laser beam. This study successfully demonstrated that axial flow velocities of laminar diffusion flames can be measured by a new technique utilizing LII signal, which does not need particle seeding unlikely to LDV or PIV techniques.

• Journal of Nutrition and Health
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• 제40권8호
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• pp.753-761
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• 2007

The objective of our study was to evaluate the dietary intakes and eating habit for seniors utilizing ten different social welfare centers in Seoul, Korea. The total number of subjects of this study was 543(male: 199, female: 344) of 60 years of age or older. The survey was performed through personal interview questionnaires from May 3rd to June 1st 2006. After assigning subjects to four categories based on family type, single, couple, joint family, and other, these categories were compared with the estimated total nutrient intakes and eating habit. Validity was assessed by comparison with 24-hour dietary recalls and dietary variety score(DVS). The results showed that senior in single family type was far lower than that of couple family type in terms of frequency of meal per day and intake of snacks. Dietary variety score represented that a single female with social security beneficiary showed the lowest variety score compared with other family type. The lunch meal provided by social welfare center turned out to be the most nutritious diet and had significant proportion of daily intakes in essential nutrients such as protein, iron, vitamin A, and vitamin C. Taken together, the family type was a significant factor and the accompaniment is another effector on dietary pattern in the elderly. We strongly suggest that the current lunch program in welfare center should be expanded to breakfast meal, and furthermore the small commodity program is also needed to provide the elderly with meal for social communication.

• 교육시설 논문지
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• 제23권1호
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• pp.43-54
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• 2016

The purpose of this study was to survey teachers' perception of classroom space utilization through analyzing the physical environment of elementary school classrooms (56 classrooms in 10 schools). Most of the teachers arranged desks in the two person parallel type (sectional layout : standard type) for their classes. Although the number was small, some classrooms used the T type, H type, U type, group type, and the teachers of such cases used these layouts for children's play activities or group learning. Some teachers changed the desk layout depending on the contents of learning or for different atmosphere of class, but about 40% of the teachers used the same classroom layout without any change during a semester. When the teachers' perception of classroom space utilization was examined according to the type and change of desk layout, the quantity and characteristics of posts, the position of posting spaces, and the size of activity spaces in the classroom, most of the teachers tended to be conventional without any characteristic, and only 16% of them were relatively active in utilizing classroom spaces. In addition, teachers of a relatively small class were more active in utilizing classroom spaces. In particular, perception was very low to utilize the classroom as a space for children's life or play activities or various types of learning. These findings suggest that it is necessary to improve teachers' perception of classroom space utilization in the future.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권11호
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• pp.555-561
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• 2001

In this paper, the low power (1.5 W) solenoid-type magnetic thin-film transformers utilizing a $Ni_{81}Fe_{19)$ core material were designed and fabricated for 5 MHz-drive DC-DC converter application. The $20\mum$ thick copper films were used as the coils. The transformers fabricated in this work have the sizes of $3.08 mm\times25.5 mm\; and\; 6.15 mm\times12.75 mm.$ The optimum design of solenoid-type magnetic thin film transformers was performed utilizing the conventional equations, a Maxwell computer simulator (Ansoft HFSS V7.0 for PC), and parameters obtained from the magnetic properties of NiFe magnetic core materials. frequency characteristics of inductance, dc resistance (R), coupling factor (k) and gain of developed transformers were measured using HP4194A impedance and gain-phase analyzer. The fabricated transformers with the size of $6.15 mm\time12.75 mm$ exhibit the inductance of $0.83 \muH$, the dc resistance of $2.3\Omega$$\Omega$, the k of 0.91 and the gain of -1 dB at 5 MHz, which show the comparable results to those reported in the recent literatures. The measured high-frequency characteristics for the fabricated transformers agreed well with those obtained by theoretical calculations .

• 대한조선학회논문집
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• 제48권2호
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• pp.113-120
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• 2011

Fins are widely used for roll stabilization of passenger ferries and high performance naval ships, among others. The Coanda effect is noticeable when a jet stream is applied tangentially to a curved wing surface since the jet can augment the lift by increasing the circulation. The Coanda effect has been found useful in various fields of aerodynamics and speculated to have practical applicability in marine hydrodynamics where various control surfaces are used to control motions of ships and the other offshore structures. In the present study, numerical computations have been performed to find proper jet momentum coefficients $C_j$ and trailing edge shapes suitable for the application of the Coanda effect to a stabilizer fin. The results show that the lift coefficient of the modified Coanda fin at the zero angle of attack ${\alpha}$ identically coincides with that of the original fin at ${\alpha}\;=\;25^{\circ}$ when Coanda jet is supplied at the rate of $C_j$ = 0.1. It is also shown that a fixed type fin stabilizer utilizing the Coanda effect can be implemented without changing the fin angle to actively control the motions of ships and the other offshore structures.