• 한국환경과학회지
• /
• 제23권5호
• /
• pp.755-761
• /
• 2014

Tourist Psychological Capacity (TPC) is an important issue of the Tourism Capacity research. We gained the tourist satisfaction through the questionnaire investigation in Mount Tai Scenic Area and obtained the tourist satisfaction function using SPSS17.0 regression analysis method. Then we got the best psychological capacity of tourists with the Marginal Satisfaction Method. Finally we verified the influencing factors on TPC. The study found that the best TPC of Mount Tai Scenic Area is 10323 persons; Female shows lower TPC than male. Moreover, female satisfaction is more easily influenced by visitors' number increasing than male satisfaction; TPC plays negative correlation with the increasing of age. Teenagers and adults have no much difference in TPC, but the seniors present a relatively lower TPC than other; The higher education, the smaller TPC.

• 물과 미래
• /
• 제20권3호
• /
• pp.237-245
• /
• 1987

경사정지수역으로 유입되는 밀도류의 거동이 흐름의 지배방정식인 연속방정식 운동량보존식 및 추적물수송식에 의하여 수치적으로 해석된다. 최대여행거리와 안정 plunge point는 바닥경사와 유입밀도 Froude 수 $Fr_e$에 지배를 받는다. 또한 그들은 바닥밀도류의 상부나 plunge point의 하류에 형성된 와와 밀접한 관계가 있다. Plunge depth는 바닥경사와 $Fr_e$의 함수이고, 본 수치실험에서 얻은 plunge depth는 발표된 실험자료나 해석해와 비교적 잘 맞았으며 이에 관한 예측식이 유도되었다.

• Korean Journal of Mathematics
• /
• 제27권4호
• /
• pp.831-841
• /
• 2019

A Radiocoloring (RC) of a graph G is a function f from the vertex set V (G) to the set of all non-negative integers (labels) such that |f(u) - f(v)| ≥ 2 if d(u, v) = 1 and |f(u) - f(v)| ≥ 1 if d(u, v) = 2. The number of discrete labels and the range of labels used are called order and span, respectively. In this paper, we concentrate on the minimum order span Radiocoloring Problem (RCP) of trees. The optimization version of the minimum order span RCP that tries to find, from all minimum order assignments, one that uses the minimum span. We provide attainable lower and upper bounds for trees. Moreover, a complete characterization of caterpillars (as a subclass of trees) with the minimum order span is given.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
• /
• pp.60-64
• /
• 2006

Propagation rates ($U_{edge}$) of various premixed, twin edge-flames were measured as a function of global strain rate ($\sigma$), mixture strength, and Lewis number (Le). Using a counterflow slot-jet burner with electrical heaters at each end, both advancing (positive $U_{edge}$) and retreating (negative $U_{edge}$) edge-flames can be studied as they propagate along the long dimension of the burner. Experimental results are presented for premixed methane/air twin flames in terms of the effects of $\sigma$ on $U_{edge}$. Both low-$\sigma$ and high-$\sigma$ extinction limits were discovered for all mixtures tested. As a result, the domain of edge-flame stability was obtained in terms of heat loss factor and normalized flame thickness, and comparison with the numerical result of other researchers was also made. For low ($CH_4/O_2/CO_2$) and high ($C_3H_8$/air) Lewis number cases, propagation rates clearly show a strong dependence on Le.

• Korea-Australia Rheology Journal
• /
• 제19권4호
• /
• pp.201-209
• /
• 2007

The present paper is concerned with non-isothermal spherical Couette flow of Oldroyd-B fluid in the annular region between two concentric spheres. The inner sphere rotates with a uniform angular velocity while the outer sphere is kept at rest. Moreover, the two spherical boundaries are maintained at fixed temperature values. Hence, the fluid is effect by two heat sources; namely, the viscous heating and the temperature gradient between the two spheres. The viscoelasticity of the fluid is assumed to dominate the inertia such that the latter can be neglected. An approximate analytical solution of the energy and momentum equations is obtained through the expansion of the dynamical fields in power series of Nahme number. The analysis show that, the temperature variation due to the external source appears in the zero order solution and its effect extends to the fluid velocity distribution up to present second order. Viscous heating contributes in the first and second order solutions. In contrast to isothermal case, a first order axial velocity and a second order stream function fields has been appeared. Moreover, at higher orders the temperature distribution depends on the gap width between the two spheres. Finally, there exist a thermal distribution of positive and negative values depend on their positions in the domain region between the two spheres.

• 한국연소학회지
• /
• 제14권1호
• /
• pp.25-30
• /
• 2009

Propagation rates ($U_{edge}$) of various premixed, twin edge-flames were measured as a function of global strain rate ($\sigma$), mixture strength, and Lewis number (Le). Using a counterflow slot-jet burner with electrical heaters at each end, both advancing (positive $U_{edge}$) and retreating (negative $U_{edge}$) edge-flames can be studied as they propagate along the long dimension of the burner. Experimental results are presented for premixed methane/air twin flames in terms of the effects of $\sigma$ on $U_{edge}$. Both low-$\sigma$ and high-$\sigma$ extinction limits were discovered for all mixtures tested. As a result, the domain of edge-flame stability was obtained in terms of heat loss factor and normalized flame thickness, and comparison with the numerical result of other researchers was also made. For low ($CH_4/O_2/CO_2$) and high ($C_{3}H_{8}$/air) Lewis number cases, propagation rates clearly show a strong dependence on Le.

• 대한기계학회논문집B
• /
• 제26권1호
• /
• pp.27-38
• /
• 2002

The effects of Reynolds number on the non-nulling calibrations of a cone-type ave-type probe in low-speed flows have been investigated at Reynolds numbers of 2.04$\times$10$^3$, 4.09$\times$10$^3$and 6.13$\times$10$^3$. The calibration is conducted at the pitch and yaw angles in ranges between -35 degrees and 35 degrees with an angle interval of 5 degrees. In addition to the calibration coefficients, reduced pitch and yaw angles, static and total pressures, and velocity magnitude are obtained through a typical non-nulling reduction procedure. The result shows that each calibration coefficient, in general, is a function of both the pitch and yaw angles, so that the pre-existing calibration data in a nulling mode are not enough in accounting far the full non-nulling calibration characteristics. Due to interference of the probe stem, the calibration coefficient are more sensitive to Reynolds number at positive pitch angles than at negative ones. The calibration data reduced in this study may serve as a guide line in the estimation of uncertainty intervals resulted from the Reynolds number effects at low Reynolds numbers.

• 한국물환경학회지
• /
• 제23권5호
• /
• pp.628-635
• /
• 2007

As the hydrologic cycle is transformed by the expansion of impermeable area as a result of the urbanization, the function of an ecosystem is deteriorated by the transformed hydrologic cycle. In this study, a SWMM code was modified to have a groundwater pumping option about rivers-aquifer interaction to be possible. The modified SWMM was applied to continuous simulations of urban runoff from Hakuicheon watershed and it was used to analyse the effect of a groundwater pumping. The modified SWMM overcame the limitation of the ground subroutine that it only simulate groundwater inflow from ground to rivers. The result of continuous simulation of groundwater pumping is that surface runoff, groundwater runoff and groundwater level are well simulated, and Modified SWMM expressed groundwater runoff by negative number (-) when groundwater level is less than river stage.

• International journal of advanced smart convergence
• /
• 제12권4호
• /
• pp.177-181
• /
• 2023

User reviews posted in the application market show high relevance with the satisfaction of application users and its significance has been proven from numerous studies. User reviews are also crucial data as they are essential for improving applications after its release. However, as infinite amounts of user reviews are posted per day, application developers are unable to examine every user review and address them. Simply addressing the reviews in a chronological order will not be enough for an adequate user satisfaction given the limited resources of the developers. As such, the following research suggests a systematical method of analyzing user reviews with a cost-benefit analysis, in which the benefit of each user review is quantified based on the number of positive/negative words and the cost of each user review is quantified by using function point, a technique that measures software size.

• 산업경영시스템학회지
• /
• 제45권4호
• /
• pp.53-60
• /
• 2022

In a group-testing method, instead of testing a sample, for example, blood individually, a batch of samples are pooled and tested simultaneously. If the pooled test is positive (or defective), each sample is tested individually. However, if negative (or good), the test is terminated at one pooled test because all samples in the batch are negative. This paper considers a queueing system with a two-stage group-testing policy. Samples arrive at the system according to a Poisson process. The system has a single server which starts a two-stage group test in a batch whenever the number of samples in the system reaches exactly a predetermined size. In the first stage, samples are pooled and tested simultaneously. If the pooled test is negative, the test is terminated. However, if positive, the samples are divided into two equally sized subgroups and each subgroup is applied to a group test in the second stage, respectively. The server performs pooled tests and individual tests sequentially. The testing time of a sample and a batch follow general distributions, respectively. In this paper, we derive the steady-state probability generating function of the system size at an arbitrary time, applying a bulk queuing model. In addition, we present queuing performance metrics such as the offered load, output rate, allowable input rate, and mean waiting time. In numerical examples with various prevalence rates, we show that the second-stage group-testing system can be more efficient than a one-stage group-testing system or an individual-testing system in terms of the allowable input rates and the waiting time. The two-stage group-testing system considered in this paper is very simple, so it is expected to be applicable in the field of COVID-19.