사무용 건축물의 운전자료 조사에 의한 최적 열원용량 분석

정광열,박종일 대한건축학회지회연합회 2005 대한건축학회지회연합회 학술발표대회논문집 Vol.1 No.1

In this paper, I investigated quality of building and H.V.A.C load used at existing building for energy analysis at office building. And I produced effect that building quality gets to energy amount used, I wish utilize to basic data when plans with heat source capacity choice. Analysis result of air conditioning equipment data to be gotten through this paper is applicable in building of other. (such as hospital, hotel, department store). Therefore, I thought that investigation and study for building of various usage can be proceeded more efficiently forward.

식생활 라이프스타일에 따른 약선음식 선택속성이 만족도와 충성도에 미치는 영향

정광열 동북아관광학회 2022 동북아관광연구 Vol.18 No.2

This study aimed to empirically verify the effects of the attributes of Yaksun food on satisfaction and loyalty according to different dietary lifestyle groups. A survey was conducted among consumers selected via convenience sampling who had experience buying Yaksun foods. Four restaurants famous for Yaksun foods in the Daegu and Gyeongju regions were selected for this survey, which was conducted from September 1st to September 21st, 2021. A total of 224 questionnaires were returned and used in the empirical analysis. The first finding was the identification of four dietary lifestyle groups: taste-seeking, health/safety-seeking, convenience-seeking, and economic value-seeking. Second, the health/safety attributes of the Yaksun food had a statistically significant effect on satisfaction for the taste-seeking group; however, for the health/safety-seeking and convenience-seeking groups, health/safety and price had a statistically significant effect on satisfaction. Third, for the taste-seeking group, health/safety and quality had a statistically significant effect on loyalty, while for the health/safety-seeking group, only health/safety had a statistically significant effect on loyalty. In contrast, health/safety, price, and quality all had statistically significant effects on loyalty in the convenience-seeking group. Finally, as a result of investigating the effect of satisfaction with medicinal foods on loyalty by dietary lifestyle group, satisfaction with medicinal foods was found to have a positive effect on loyalty among the taste-seeking, health/safety-seeking, and convenience-seeking groups. 본 연구에서는 식생활 라이프스타일에 따른 집단에 따라 약선음식 선택속성이 만족도와 충성도에 미치는 영향을 실증적으로 검증해 보고자 하였다. 본 연구에서는 편의표본추출법을 이용하여 약선음식을 구입해 본 경험을 가진 소비자들을 대상으로 설문조사를 실시하였다. 대구와 경주지역에서 유명한 약선음식 전문식당 4곳을 선정하여 설문조사를 실시하였다. 조사기간은 2021년 9월 1일∼2021년 9월 21일까지 실시하였으며, 총 224부를 실증분석에 사용하였다. 연구결과를 요약해 보면, 첫째, 식생활 라이프스타일에 대한 4개의 집단은 맛추구형, 건강추구형, 경제가치추구형으로 나타났다. 둘째, 맛추구군집은 약선음식 선택속성중 건강/안전요인이 만족도에 통계적으로 유의한 영향을 미치는 것으로 나타났고, 건강/안전성추구군집과 편의성추구군집에서는 건강/안전요인과 가격요인이 만족도에 통계적으로 유의한 영향을 미치는 것으로 나타났다. 셋째, 맛추구군집은 건강/안전요인과 품질요인이 충성도에 통계적으로 유의한 영향을 미치는 것으로 나타났고, 건강/안전성추구 군집은 건강/안전요인이 충성도에 통계적으로 유의한 영향을 미치는 것으로 나타났다. 그리고 편의성추구군집에서는 건강/안전요인과 가격요인, 품질요인 모두 충성도에 통계적으로 유의한 영향을 미치는 것으로 나타났다. 넷째, 식생활 라이프스타일 군집별로 약선음식 만족도가 충성도에 미치는 영향을 알아본 결과 본 결과 맛추구군집과 건강/안전성추구군집, 편의성추구군집 모두 약선음식 만족도가 충성도에 긍정적인 영향을 미치는 것으로 나타났다.

Numerical simulations of two-dimensional floating breakwaters in regular waves using fixed cartesian grid

정광열,이영길 대한조선학회 2014 International Journal of Naval Architecture and Oc Vol.6 No.2

The wave attenuation by floating breakwaters in high amplitude waves, which can lead to wave over-topping and breaking, is examined by numerical simulations. The governing equations, the Navier-Stokes equations and the continuity equation, are calculated in a fixed Cartesian grid system. The body boundaries are defined by the line segment connecting the points where the grid line and body surface meet. No-slip and divergence free conditions are satisfied at the body boundary cell. The nonlinear waves near the moving body is defined using the modified marker-density method. To verify the present numerical method, vortex induced vibration on an elastically mounted cylinder and free roll decay are numerically simulated and the results are compared with those reported in the literature. Using the present numerical method, the wave attenuations by three kinds of floating breakwaters are simulated numerically in a regular wave to compare the performance.

선수형상이 갑판침입수에 미치는 영향에 관한 실험 및 수치적 연구

정광열,이영길,하윤진,채순재 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.11

본 연구에서는 140,000DWT FPSO의 수평면 선수형상을 삼각형, 타원형, 원형의 세 가지로 변화시키며 규칙파 중에서 발생하는 갑판침입수 현상을 비교, 분석하였다. 고정된 선체에서 발생하는 갑판침입수를 수치적으로 시뮬레이션 하여 선체주위 유동과 갑판상 유동에 있어서의 차이를 분석하였으며, 또한 heave와 pitch가 자유로운 선박에서의 갑판침입수 실험을 통하여 선체운동의 변화와 갑판침입수의 갑판상 유동을 비교하였다. 선체가 고정된 경우 선수 끝단의 수평면상 물의 입사각도가 갑판침입수 양에 큰 영향을 미쳐서 삼각형 선수에서 가장 작은 충격압력이 발생하나, 선체운동이 자유로운 경우 선수운동이 갑판침입수 양에 큰 영향을 미치게 되어 원형 선수에서 가장 작은 충격압력이 나타남을 보였다. 끝으로, 만일 선체 운동이 동일한 조건이라면, 타원형 선수가 삼각형과 원형선수에 비하여 수직벽에서 발생하는 충격압력이 작음을 수치시뮬레이션을 수행하여 보이기도 하였다.

수두차를 이용한 해저퇴적물 흡입현상의 수치시뮬레이션

정광열(K.-L. Jeong),이영길(Y.-G. Lee),정우철(Uh-Cheul Jeong),손충렬(Choong-Yul Son) 한국전산유체공학회 2005 한국전산유체공학회 학술대회논문집 Vol.2005 No.10

고정된 직사각형 격자계에서 움직이는 물체주위 자유수면유동 계산을 위한 수치기법의 개발

정광열(K.L. Jeong),이영길(Y.G. Lee),하윤진(Y.J. Ha) 한국전산유체공학회 2011 한국전산유체공학회 학술대회논문집 Vol.2011 No.5

In this research, a numerical simulation method is developed for moving body in free surface flows using fixed staggered rectangular grid system. The non-linear free surface near the body is defined by marker-density method. The body boundary is defined by line segment connecting the points where the body surface and grid line meet. Continuity equation and Navier-Stokes equations are used as governing equations and the equations are coupled with two-step projection method. The velocities and pressures of body boundary and free surface cells are calculated with simultaneous iterative method. To treat a body movement in a fixed grid system, the volume displaced by moving body is added to the divergence of the body boundary cell. For the verification of the present numerical method, vortex shedding period of advancing cylinder is calculated and the period is compared with existing experiment results. Moreover, added mass and damping coefficients of a vertically excited box are calculated and the computed results are compared with published experiment results. Impulsive pressure and water level variation due to sloshing phenomenon are simulated and the results are compared with published experiment results. Varying the plunger shape, the waves generated by plunging type wave maker are compared with the 2nd order Stokes wave theory. The plunger shape generating the wave that shows the best agreement with the theory is represented.

수정된 밀도함수법을 이용한 SPILLING BREAKER의 수치시뮬레이션

정광열(K.-L. Jeong),이영길(Y.-G. Lee) 한국전산유체공학회 2012 한국전산유체공학회 학술대회논문집 Vol.2012 No.11

The differences of physical properties of water and air are the source of instabilities of the numerical solutions considering the free surface flow. The most typical methods for the free surface such as Volume Of Fluid(VOF) and Level-Set(LS) methods impose transient zones where the physical prosperities vary gradually for the stabilities of solutions. The thickness of the transient zone is the source of the error of a solution. The marker-density method does not use such a transient zone. In the traditional marker-density method, however, the air velocities of free surface cells are extrapolated from the water velocity and the pressures on the free surface are extrapolated form the air pressures for the stability of a solution. Those extrapolations are also the source of the error of the solution. In this study, the marker-density method is modified to calculate the air velocities of free surface cells by determining the pressure and velocity on the free surface to get continuous pressure gradient and viscous stress. Two-dimensional steady spilling breakers behind of a submersed hydrofoil is simulated using INHAWAVE-II including the modified marker-density(MMD) method. The results are compared with the results of Fluent V6.3 including VOF method and published research results. Moreover, three-dimensional spilling breaker near a wedge shaped ship model is simulated using INHAWAVE-II. And the results are compared with the results of Fluent V6.3 and exist experimental data.

고정된 2차원 직사각형 격자계에서 자유동요하는 물체주위 유동의 수치시뮬레이션

정광열(K.-L. Jeong),이영길(Y.-G. Lee) 한국전산유체공학회 2011 한국전산유체공학회 학술대회논문집 Vol.2011 No.11

In this research a numerical simulation method is developed for free surface flows around a freely oscillating body in fixed two-dimensional rectangular grid system. The non-linear free surface near the body is defined by modified marker-density method. The body boundary is defined by line segments connecting the points where the body surface and grid lines meet. Continuity equation and Navier-Stokes equations are used as governing equations and the equations are coupled with two-step projection method. The subgrid-scale turbulence model is applied in order to consider turbulence effects. To treat body movements in a fixed grid system. the volume displaced by moving body is added to the divergence of the body boundary cell. For the verification of the present numerical method, the vortex induced vibrations of an elastically mounted cylinder are calculated, and the amplitudes are compared with existing calculation results. Moreover, the free roll decay of a floating box is numerically simulated, and the results are compared with published experiment results.

유근피 추출물의 생리활성

정광열 ( Kwang Yeol Jeong ),김미림 ( Mi Lim Kim ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2012 한국식품저장유통학회지 Vol.19 No.1

This study was carried out for the functional investigation of the Ulmus pumila L. extracts for use in functional-food processing. Extracts of Ulmus pumila L. were obtained using distilled water and 70% ethanol, and the extracts were tested for their electron-donating ability, SOD-like activity, nitrate-scavenging ability, and anticancer (MDA and A 549 cells) activity. The extraction yields of the water and ethanol extracts were 12.7 and 12.0%, respectively; the polyphenol contents were 623.5 ± 2.4 and 710.5 ± 2.1 mg/100 g; the electron-donating ability was high in proportion with the density; and the water extract was higher than the ethanol extract (76 and 64%, respectively) at 1,000 ppm. In all the 1,000 ppm densities, the SOD-like activity of the water extract was far higher than that of the ethanol extract (53 and 38%, respectively), and the nitrite-scavenging ability of the ethanol extract was higher than that of the water extract (47 and 43%, respectively). As for the anticancer ability at 1,000 ppm, it was 62% in the water extract and 42% in the ethanol extract in the MDA cell, and 60% in the water extract and 45% in the ethanol extract in the A 549 cell. Thus, the proliferation inhibition ability of the water extract against cancer cells was found to be far higher than that of the ethanol extract (60 and 45%, respectively).

2차원 Beach에서 쇄파의 시뮬레이션을 위한 수치계산기법의 비교

정광열(K. L. Jeong),이영길(Y.-G. Lee) 한국전산유체공학회 2004 한국전산유체공학회 학술대회논문집 Vol.2004 No.-

Unsteady nonlinear wave motions on the free surface over a plane beach of constant slope are numerically simulated using a finite difference method in rectangular grid system. Two-dimensional Navier-Stokes equations and the continuity equation are used for the computations. Irregular leg lengths and stars are employed near the boundaries of body and free surface to satisfy the boundary conditions. Also, the free surface which consists of markers or segments is determined every time step with the satisfaction of kinematic and dynamic free surface conditions. Moreover, marker-density method is also adopted to allow plunging jets impinging on the free surface. The second-order Stokes wave theory and solitary wave theory are employed for the generation of waves on the inflow boundary. For the simulation of wave breaking phenomena, the computations are carried out with the plane beach of constant slope in surf zone. The results are compared with each other. The marker-density method is better then the hybrid method. Also they are compared with other existing experimental results. The Agreement between the experimental data and the computation results is good.