• Title/Summary/Keyword: neutral difference equation

Search Result 28, Processing Time 0.021 seconds

A Study on the Impact of Cosmetics Blog Information Characteristics on credibility in the Process of Word of Mouth Acceptance and Word of Mouth Effect (화장품 블로그의 정보특성이 구전수용과정의 신뢰와 구전효과에 미치는 영향)

  • Park, Jeong-Mi;Hwang, Sun-Jin
    • Journal of the Korean Society of Costume
    • /
    • v.62 no.2
    • /
    • pp.13-25
    • /
    • 2012
  • The purpose of this research is to study the influence over confidence and Word-Of-Mouth (WOM) effect in the acceptance process of WOM by information characteristics(consensus, vividness, and message neutrality) of individual cosmetic blog, reflecting that it is widely spreading over the public. Online survey for the consumers using such blogs was performed to collect data(N=200), and credibility analysis through Cronbach-${\alpha}$ and Structural Equation Model(SEM) analysis using AMOS 18.0 were performed. The analysis results are as follows; First, vivid information and neutral message increase WOM effect through the improvement of consumers' credibility whereas information consensus doesn't positively influence over credibility. Second, the examination of a moderating effect by type of cosmetics demonstrated that the consumers of basic cosmetics have most confidence in vivid information, and those of color cosmetics do more confidence in neutral message. Therefore, there is a difference in the credibility factor of online WOM depending on the type of cosmetics consumption so that differentiated information provision strategies for cosmetics groups should be established based on it.

Particle Simulation Modelling of a Beam Forming Structure in Negative-Ion-Based Neutral Beam Injector (중성빔 입사장치에서 빔형성 구조의 입자모사 모형)

  • Park, Byoung-Lyong;Hong, Sang-Hee
    • Nuclear Engineering and Technology
    • /
    • v.21 no.1
    • /
    • pp.40-47
    • /
    • 1989
  • For the effective design of a beam forming structure of the negative-ion-based neutral beam injector, a computer program based on a particle simulation model is developed for the calculation of charged particle motions in the electrostatic fields. The motions of negative ions inside the acceleration tube of a multiple-aperture triode are computed at finite time steps. The electrostatic potentials are obtained from the Poisson's equation by the finite difference method. The successive overrelaxation method is used to solve the matrix equation. The particle and force weighting methods are used on a cloud-in-cell model. The optimum design of the beam forming structure has been studied by using this computer code for the various conditions of elctrodes. The effects of the acceleration-deceleration gap distance, the thickness of the deceleration electrode and the shape of the acceleration electrode on beam trajectories are exmined to find the minimum beam divergence. Some numerical illustrations are presented for the particle movements at finite time steps in the beam forming tubes. It is found in this particle simulation modelling that the shape of the acceleration electrode is the most significant factor of beam divergence.

  • PDF

Contributions of Heating and Forcing to the High-Latitude Lower Thermosphere: Dependence on the Interplanetary Magnetic Field

  • Kwak, Young-Sil;Richmond, Arthur;Ahn, Byung-Ho;Cho, Kyung-Suk
    • Journal of Astronomy and Space Sciences
    • /
    • v.27 no.3
    • /
    • pp.205-212
    • /
    • 2010
  • To better understand the physical processes that maintain the high-latitude lower thermospheric dynamics, we have identified relative contributions of the momentum forcing and the heating to the high-latitude lower thermospheric winds depending on the interplanetary magnetic field (IMF) and altitude. For this study, we performed a term analysis of the potential vorticity equation for the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions, with the aid of the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM). Difference potential vorticity forcing and heating terms, obtained by subtracting values with zero IMF from those with non-zero IMF, are influenced by the IMF conditions. The difference forcing is more significant for strong IMF $B_y$ condition than for strong IMF $B_z$ condition. For negative or positive $B_y$ conditions, the difference forcings in the polar cap are larger by a factor of about 2 than those in the auroral region. The difference heating is the most significant for negative IMF $B_z$ condition, and the difference heatings in the auroral region are larger by a factor of about 1.5 than those in the polar cap region. The magnitudes of the difference forcing and heating decrease rapidly with descending altitudes. It is confirmed that the contribution of the forcing to the high-latitude lower thermospheric dynamics is stronger than the contribution of the heating to it. Especially, it is obvious that the contribution of the forcing to the dynamics is much larger in the polar cap region than in the auroral region and at higher altitude than at lower altitude. It is evident that when $B_z$ is negative condition the contribution of the forcing is the lowest and the contribution of the heating is the highest among the different IMF conditions.

Characteristics of Thermal Environments and Evaluation of Thermal Comfort in Office Building in Winter (겨울철 사무실내 온열환경 특성 및 쾌적성 평가)

  • Bae, G.N.;Lee, C.H.;Lee, C.S.;Choi, H.C.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.7 no.2
    • /
    • pp.310-318
    • /
    • 1995
  • In this study, indoor thermal parameters were measured to investigate the characteristics of thermal environments and 138 occupants were questioned to evaluate Korean thermal comfort in office building in winter. Thermal sensation was estimated by using PMV(Predicted Mean Vote) and ET*(New Effective Temperature) indices. Comparing present experimental result with international standards and that of other research, Korean thermal responses were discussed. Seasonal difference between summer and winter was also discussed. It was found that TSV(Thermal Sensation Vote) is more sensitive than PMV to the variation of temperature and that the measured percentage of dissatisfied is higher than PPD(Predicted Percentage of Dissatisfied) in real office building environments. By regression analysis, the following regression equation has been obtained; TSV=0.432ET*-8.814 and neutral temperature is $20.4^{\circ}C$ in this case. Thermal comfort range based on 80% satisfaction is also $19.4{\sim}22.4^{\circ}C$.

  • PDF

A Study on the Measurement of the Normal Tracheal Length in Korea adults (한국성인의 기관 길이 측정에 관한 연구)

  • 나명훈
    • Journal of Chest Surgery
    • /
    • v.28 no.8
    • /
    • pp.766-771
    • /
    • 1995
  • The trachea is defined as the airway from the inferior border of the cricoid cartilage to the top of the carinal spur. This paper would confirm the normal tracheal length of Korean adults through the actual measurement using the fiberoptic bronchoscopy. The subjects of this study were 25 patients, 13 males and 12 females between the age of 20 to 69 without abnormality on the neck, trachea, mediastinum and lung pharenchyme on the preoperative chest X-ray, who received the operations from the period of July to September, 1994. For those patients who had heart diseases, the cardiothoracic ratio was below 50%. The measurement was performed on the patients with endotracheal intubation under the general anesthesia in supine and neutral position. The tracheal length was calculated by the difference between the length from the tip of the endotracheal tube [E-tube to carina and to the needle which was inserted into the E-tube at the lower border of the palpated cricoid cartilage, by inserting the broncoscopy through the E-tube. The result was as follow : 1 The measured tracheal length for men was 11.8 0.2 cm[mean standard deviation and women was 10.5 0.3 cm, and that was longer than this [p<0.01 . The average was 11.2 1.0 cm and the standard error was 0.20 cm. 2 According to the correlation between the tracheal length to weight, height[Ht , age, and body surface area[BSA respectively, the Ht [p=0.003 , age [p=0.055 , and the BSA[p=0.017 were significant, while weight was not [p=0.314 . 3 From the regression analysis of the tracheal length[T.L. to the Ht, Age, and the BSA which were significant, the following equation was derived.i Ht : T.L.= -1.29 + 0.076 x Ht [P=0.003 ii Age: T.L.= 10.04 + 0.028 x Age [P=0.055 iii BSA : T.L.= 5.60 + 3.48 x BSA [P=0.017 iv In multi-regression : T.L. = -4.15 + 0.034 x Age + 0.085 x Ht [P=0.0002]

  • PDF

Filtering Rate with Effect of Water Temperature and Size of Two Farming Ascidians Styela clava and S. plicata, and a Farming Mussel Mytilus edulis (수온과 개체크기에 따른 양식산 미더덕, 흰멍게, 진주담치의 여수율)

  • KIM Yong Sool;Moon Tae Seok
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.31 no.2
    • /
    • pp.272-277
    • /
    • 1998
  • Filtering rates of two farming ascidians Styela clava and S. plicata, and of a farming mussel Mytilus edulis were experimentally investigated with reference to effects of water temperature and size. Absorptiometric determinations of filtering rates were carried out in a closed system with experimental animals being decreased indicate dyes neutral red. Optical density (OD) of 440 nm in path length 22 mm cell used as the indication of food particles absorption was appeared directly in proportion with the concentration of neutral red dyes. The filtering rate F is calculated by Kim's equation $F\;=\;V(1-e^{-z})$, where V is the water volume ($\ell$) in the experimental jar, and Z is the decreasing coefficient of OD as meaning of instantaneous removal speed as In $C_t\;=\;In\;C_{o}-Z{\cdot}t$, in this formula $C_t$ is OD at the time t. Filtering rate of S. clava increased as exponential function with increasing temperature while not over critical limit, and the critical temperature for filtering rate was assumed to be between $28^{\circ}C$ and $29^{\circ}C$. In case of S. plicata, the critical temperature was to be below $13^{\circ}C$, and through the temperature range $15\~25^{\circ}C$ appeared a little difference in level even though with significant. M. edulis was not appear any significant effects by water temperature less than $29^{\circ}C$. The model formula derived from the results is as below, where F is filtering rate (${\ell}/hr/animal$), T is water temperature ($^{\circ}C$), and DW is dry meat weight (g) of experimental animal. $$S.\;Clava;\;F\;=\;e xp\;(0.119\;T-4.540)\;(DW)^{0.6745},\;T<29^{\circ}C$$) $$S.\;plicata;\;F\;=\;e xp\;(A_t)\;(DW)^{0.5675},\;(13^{\circ}C $$[A_t =-8.56+0.6805\;T-0.0153\;T^2]$$ $$M.\;edulis;\;F\;=\;0.3844\;(DW)^{0.4952},\;<29^{\circ}C$$)

  • PDF

Effect of Patient's Positioning on the Grade of Tendinosis and Visible Range of Infraspinatus Tendon on Ultrasound (초음파 영상에서 극하근 힘줄병의 단계와 관찰가능 범위에 환자의 자세가 미치는 영향)

  • Jee Won Chai;Joo-ho Lee;Dong Hyun Kim;Jina Park;So-Hee Oh;Su-Mi Shin
    • Journal of the Korean Society of Radiology
    • /
    • v.84 no.3
    • /
    • pp.627-637
    • /
    • 2023
  • Purpose To investigate the effect of patient positioning on tendinosis grade, visible range, and infraspinatus tendon (IST) thickness, and to determine the feasibility of internal rotation (IR) position to assess IST on ultrasound (US). Materials and Methods This study included 52 shoulders of 48 subjects who were evaluated for IST in three different positions: neutral position (N), IR, and position with the ipsilateral hand on the contralateral shoulder (HC). Two radiologists retrospectively graded IST tendinosis from grade 0 to grade 3 and the visible range from grade 1 to grade 4. The thickness of the IST was measured by another radiologist with a short-axis view. A generalized estimating equation was used for statistical analysis. Results The tendinosis grades were higher in the HC position than in the IR position, with a cumulative odds ratio of 2.087 (p = 0.004, 95% confidence interval [CI]: 1.268-3.433). The tendinosis grades in the HC position (p = 0.370) and IR position (p = 0.146) were not significantly different from those in the N position. The overall difference in IST thickness was significant (p < 0.001), but the visible range (p = 0.530) was not significantly different according to position. Conclusion Patient positioning significantly affected the grade of tendinosis and thickness but not the visible range of the IST. The IR position is a feasible position for assessing the IST on US.

Comparative Study on the Carbon Stock Changes Measurement Methodologies of Perennial Woody Crops-focusing on Overseas Cases (다년생 목본작물의 탄소축적 변화량 산정방법론 비교 연구-해외사례를 중심으로)

  • Hae-In Lee;Yong-Ju Lee;Kyeong-Hak Lee;Chang-Bae Lee
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.25 no.4
    • /
    • pp.258-266
    • /
    • 2023
  • This study analyzed methodologies for estimating carbon stocks of perennial woody crops and the research cases in overseas countries. As a result, we found that Australia, Bulgaria, Canada, and Japan are using the stock-difference method, while Austria, Denmark, and Germany are estimating the change in the carbon stock based on the gain-loss method. In some overseas countries, the researches were conducted on estimating the carbon stock change using image data as tier 3 phase beyond the research developing country-specific factors as tier 2 phase. In South Korea, convergence studies as the third stage were conducted in forestry field, but advanced research in the agricultural field is at the beginning stage. Based on these results, we suggest directions for the following four future researches: 1) securing national-specific factors related to emissions and removals in the agricultural field through the development of allometric equation and carbon conversion factors for perennial woody crops to improve the completeness of emission and removals statistics, 2) implementing policy studies on the cultivation area calculation refinement with fruit tree-biomass-based maturity, 3) developing a more advanced estimation technique for perennial woody crops in the agricultural sector using allometric equation and remote sensing techniques based on the agricultural and forestry satellite scheduled to be launched in 2025, and to establish a matrix and monitoring system for perennial woody crop cultivation areas in the agricultural sector, Lastly, 4) estimating soil carbon stocks change, which is currently estimated by treating all agricultural areas as one, by sub-land classification to implement a dynamic carbon cycle model. This study suggests a detailed guideline and advanced methods of carbon stock change calculation for perennial woody crops, which supports 2050 Carbon Neutral Strategy of Ministry of Agriculture, Food, and Rural Affairs and activate related research in agricultural sector.