• 가정과삶의질연구
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• 제27권1호
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• pp.181-196
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• 2009

This study compared mother-toddler verbal interaction by play type (traditional play, free play, block play), and child's sex and age. Subjects were 10 boys and 10 girls ranging in age from 25- to 36-months and their mothers. An observer videotaped the children and their mothers at play in their homes. Results showed that (1) Mothers attempted more positive verbal interaction in traditional than in block play. (2) Mothers expressed more positive emotion in free than in traditional and block play. (3) Mothers more answer 'reflection' in traditional than in free play (4) Toddlers attempted more positive verbal interaction in block than in traditional and free play. (5) Toddler's positive emotion express was not distinguished by play type or by child's sex or age. (6) From 31- to 36-months's boys expressed more play situation than from 25- to 30-months' girls. This study provides groundwork for mother-toddler traditional play programs with potential for improving positive expression of emotion and language development.

• 대한수학회보
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• 제29권2호
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• pp.265-275
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• 1992

The characteristic free representation theory of the general linear group has found a wide range of applications, ranging from the theory of free resolutions to the symmetric function theory. Representation theory is used to facilitate the calculation of explicit free resolutions of large classes of ideals (and modules). Recently, K. Akin and D. A. Buchsbaum [2] realized the Jacobi-Trudi identity for a Schur function as a resolution of GL$_{n}$-modules. Over a field of characteristic zero, it was observed by A. Lascoux [6]. T.Jozefiak and J.Weyman [5] used the Koszul complex to realize a formula of D.E. Littlewood as a resolution of schur modules. This leads us to further study resolutions of Schur modules of a particular form. In this article we will describe some new classes of finite free resolutions associated to the Pieri type skew Young diagrams. As a special case of these finite free resolutions we obtain the generalized Koszul complex constructed in [1]. In section 2 we review some of the basic difinitions and properties of Schur modules that we shall use. In section 3 we describe certain exact complexes associated to the Pieri type skew partitions. Throughout this article, unless otherwise specified, R is a commutative ring with an identity element and a mudule F is a finitely generated free R-module.e.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1127-1130
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• 2009

The effects of different dihydroxybenzoic acid (DHB) isomers, when used as matrix materials in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), were investigated in analyses of polyethylene glycol (PEG) polymers. PEG polymers ranging from 400 to 8,000 Da were prepared in different DHB isomer matrices using solvent-based and solvent-free methods. PEG samples were detected only in matrices of 2,3-DHB, 2,5-DHB, and 2,6-DHB while the most intense peaks were observed using 2,6-DHB in both solvent-free and solvent-based preparations.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.61-69
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• 1999

A dynamic stability test was performed to determine dynamic stability derivatives for the pure pitching motion of air-to-ground missile model in the low speed wind tunnel. The free vibration technique was employed to acquire oscillation characteristics of the model for damping coefficients. Damping coefficients are obtained by the method of logarithmic decrement. Results show good damping effects and stability capability at Mach numbers 0.1 and 0.2, with the angle of attack ranging from -15 to +20 degrees.

• Advances in aircraft and spacecraft science
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• 제10권4호
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• pp.303-315
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• 2023

The primary goal of this research is to investigate flow separation phenomena using various turbulence models. Also investigated are the effects of free-stream turbulence intensity on the flow over a NACA 0018 airfoil. The flow field around a NACA 0018 airfoil has been numerically simulated using RANS at Reynolds numbers ranging from 100,000 to 200,000 and angles of attack (AoA) ranging from 0° to 18° with various inflow conditions. A parametric study is conducted over a range of chord Reynolds numbers for free-stream turbulence intensities from 0.1 % to 0.5 % to understand the effects of each parameter on the suction side laminar separation bubble. The results showed that increasing the free-stream turbulence intensity reduces the length of the separation bubble formed over the suction side of the airfoil, as well as the flow prediction accuracy of each model. These models were used to compare the modeling accuracy and processing time improvements. The K- SST performs well in this simulation for estimating lift coefficients, with only small deviations at larger angles of attack. However, a stall was not predicted by the transition k-kl-omega. When predicting the location of flow reattachment over the airfoil, the transition k-kl-omega model also made some over-predictions. The Cp plots showed that the model generated results more in line with the experimental findings.

• 한국군사과학기술학회지
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• 제22권4호
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• pp.467-474
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• 2019

Recently, optical phased array(OPA) based laser detection and ranging(LADAR) has gained great interest to replace the traditional mechanical light detection and ranging technique(LiDAR). In OPA-based LADAR, it is well known that phases of laser pulses traveling through each of channels should be the same to obtain a narrow free-space single beam without noise-like ripples in the far field. However, it is difficult to provide such ideal condition due to the fabrication errors. To tackle this problem, any algorithms should be necessary to compensate the initial random phases of each channel in OPA antenna. In this paper, we propose a hill-climbing based phase calibration algorithm and evaluate the performance of the proposed algorithm.

• 한국식품과학회지
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• 제28권6호
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• pp.1135-1141
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• 1996

본 연구는 시판되고 있는 새우젓의 맛과 밀접한 관계를 가지고 있는 함질소 엑스성분을 분석하여 품질상태를 파악하는 한편 품질개선과 품질지표에 관한 자료를 얻고자 하였다. 시료는 4개 회사 제품을 1994년 7월과 8월, 그리고 1995년 1월과 11월에 구입하여 고형물과 액즙으로 구분한 다음 엑스분을 추출하여 엑스분질소, 유리아미노산, oligopeptide류. 핵산관련물질, betaine류, 4급암모늄염기 및 구아니디노 화합물을 분석하였다. 새우젓의 수분함량은 고형물보다 액즙에서 6.1% 높고, 단백질은 고형물에서 4.1% 높았다. 염분은 $21.7{\sim}25.3%$(평균 24.1%)로서 매우 높았으며, 저염화가 요망된다. 엑스분 질소는 $430{\sim}528{\;}mg$(평균 458 mg)으로서 젓새우와 같은 수준이었고, 멸치액젓의 53.3% 수준이었다. 새우젓에서는 32종의 유리아미노산이 검출되었고, 총량은 $1,509{\sim}2,131\;mg$(평균 1,803 mg) 범위로서 멸치액젓의 42.0%수준이었다. 함량이 많은 유리아미노산으로는 lysine, glutamic acid, leucine, arginine, glycine, histidine, glutamine의 순이었다. 핵산관련물질은 $1.38{\sim}7.41\;{\mu}mol$ (평균 $3.46\;{\mu}mol) 범위로서 시판 멸치액젓과 비슷한 수준이었고, 제품에 따른 차이가 많았다. Betaine류는 homarine, trigonelline, ${\beta}-alaninebetaine$, glycinebetaine이 검출되었으며, homarine이 $97{\sim}224\;mg$ (평균 163 mg)으로 대부분을 차지하였고, 그 외에는 미량이었다. 새우젓의 TMAO는 $13{\sim}80{\;}mg$(평균 43 mg), TMA는 $12{\sim}280{\;}mg$ (평균 155 mg) 범위였고, 원료에 비해 TMAO는 낮았고, TMA는 높았다. Creatine과 creatinine는 6 mg과 1 mg 이하로서 미량이었다. 새우젓에서 함질소 엑스성분 조성은 유리아미노산이 평균 63.4%로서 가장 많았으며, 다음은 oligopeptide 11.8%, TMAO와 TMA 9.7% 핵산관련물질 4.4%, betaine류 3.8%, creatine과 creatinine 0.3%의 순으로서 질소의 회수율은 평균 93.4%였다.

• 대한약침학회지
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• 제11권2호
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• pp.63-73
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• 2008

Objectives The purpose of this study is to investigate the effects of Crataegi Fructus Pharmacopuncture(CFP) on the adipogenesis in 3T3-L1 cells, lipolysis in rat epididymal adipocytes and histological changes in porcine adipose tissue. Methods Inhibiton of preadipocyte differentiation and/or stimulation of lipolysis play important roles in reducing obesity. 3T3-L1 preadipocytes were differentiated with adipogenic reagents by incubating for 3days in the absence or presence of CFP ranging from 0.01 to 1mg/mL. The effect of CFP on adipogenesis was examined by measuring GPDH activity and by Oil Red O staining. Mature adipocytes from rat epididymal fat pad was incubated with CFP ranging from 0.01 to 1mg/mL for 3 hrs. The effect of CFP on lipolysis was examined by measuring free glycerol released. Fat tissue from pig skin was injected with CFP ranging from 0.1 to 10mg/mL to examine the effect of CFP on histological changes under light microscopy. Results The following results were obtained from present study on adipogenesis of preadipocytes, lipolysis of adipocytes and histological changes in fat tissue. 1. Crataegi Fructus Pharmacopuncture inhibited adipogenic differentiation at the concentration of 1.0mg/mL. 2. Crataegi Fructus Pharmacopuncture decreased the activity of glycerol-3-phosphate dehydrogenase(GPDH) at the concentration of 0.1mg/mL. 3. Crataegi Fructus Pharmacopuncture ok. lipolysis at the concentration of 0.1mg/ml. 4. Crataegi Fructus Pharmacopuncture ranging 0.1 to 10mg/mL failed to exert lysis of cell membrane in porcine fat tissue. Conclusions These results suggest that Crataegi Fructus Pharmacopuncture at relatively high concentration inhibited adipogenesis and increased lipolysis of adipocytes. However, Crataegi Fructus Pharmacopuncture didn't exert any effect on lysis of cell membrane in fat tissue.

• 한국대기환경학회지
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• 제27권6호
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• pp.681-691
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• 2011

The size distributions of smoke particles from fire are prerequisite for the studies on fire detection and adverse health effects. Above the flame of the fire, coagulation dominates and the smoke particles grow from 1 to 50 nm up to 100 to 3,000 nm, sizes ranging from the free-molecular regime to the continuum regime. The characteristics of the agglomeration of the smoke particles are well known, independently for each of the free-molecular and continuum regimes. However, there are not many systematic studies in the entire regime by the complexity of the mechanisms. The purpose of this work is to find the characteristics of the development of the size distribution of smoke particles by agglomeration in the entire size range covering the free-molecular regime, via transition regime, to the near-continuum and continuum regime for each variation of parameters such as fractal dimension, primary particle size and dimensionless coagulation time. In this work, the dynamic equation for the discrete-size spectrum of the particles was solved using a nodal method based on the modification of a sectional method. In the calculation, the collision frequency function for the entire regime, which is derived by using the concept of collision volume and general enhancement function, was applied. The self-preserving size distribution for the entire regime is compared with the ones for the free-molecular or continuum regimes for each variation of the parameters.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3099-3102
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• 2010

A label-free DNA detection method was developed for a simple electrochemical DNA sensor with a short assay time. Self-assembled monolayers of peptide nucleic acid were used as a probe on gold electrodes. The formation of the self-assembled monolayers on the gold electrodes was successfully checked by means of cyclic voltammetry. The target DNA, hybridized with peptide nucleic acid, can be detected by the anodic peak current of ferrocene dendrimers, which interact electrostatically with the target DNA. This anodic peak current was measured by square wave voltammetry at 0.3 V to decrease the detection limit on the order of the nanomolar concentrations. As a result, the label-free electrochemical DNA sensor can detect the target DNA in concentrations ranging from 1 nM to $1\;{\mu}M$ with a detection limit of 1 nM.