• 한국정보통신학회논문지
• /
• 제14권12호
• /
• pp.2836-2842
• /
• 2010

본 논문에서는 다양한 3D 게임 진행에서 NPC들을 속성에 따라 그룹핑하는 방법을 제시한다. 움직임이 없는 NPC는 가버필터링 결과에서 특이한 방향성 특성을 띄는 경향이 있지만 사람이나 동물과 같은 NPC는 그렇지 않다. 그룹핑을 위해 우선 NPC 객체 내부의 방향성과 주파수 영역의 특징을 분석하고 각각을 24개의 가버 필터뱅크로 구성하며 필터의 스케일과 방향에 따른 24차원 특징 벡터를 산출한다. 추출된 벡터는 특정 방향에 따른 에너지를 나타낸다. 이러한 에너지는 NPC 내부에 있는 객체 질감의 특정 방향에 대한 크기를 나타내고 있기 때문에 NPC들을 그룹핑 속성으로 이용하였다. 제안한 방법은 게임진행에서 유사한 속성을 가진 NPC들이 자동으로 그룹핑되어 전략적이고 속도감 있게 플레이 할 수 있는 기능을 제공한다.

• 소음진동
• /
• 제8권6호
• /
• pp.1137-1143
• /
• 1998

This paper describes the method to measure of the vibrational power transmitted from the vibration source to the supporting structure in the horizontal direction. Generally, it is impossible to measure horizontal forces at the coupling points. However. the vibrational Power transmitted in the horizontal direction can be measured by using indirect method that is based on the mechanical impedance and velocities at the coupling points. We proposed the method to estimate the vibrational power when the vibration source and supporting structure cannot be separated. In this paper. the vibrational power transmitted in the horizontal direction is also estimated by using this method. The estimated and measured results of the mobilities at the coupling point and vibrational power in the horizontal direction are compared. It is shown that the estimated results agree well with the measured results. For the supporting structure with multiple coupling points, the other coupling points should be considered for measuring the vibrational power transmitted through one coupling points. We examine the effects of other coupling points and measure the vibrational power without considering the other coupling points.

• 한국세라믹학회지
• /
• 제36권9호
• /
• pp.887-892
• /
• 1999

The inner crack-like pore with controlled amount of Ca impurity in the high purity alumina single crystal sapphire had been created by micro-fabrication technique which includes ion implanation photo-lithography Ar ion milling and hot press technique. The crack-like pores in two-hour hot pressed specimen were extremely stable even after heat treating at 1,80$0^{\circ}C$ for 5 hours almost no healing was observed. But the crack-like pores in one-hour hot pressed specimen at 1,30$0^{\circ}C$ were healed by heat treatment and the amount of healing was increased with the heat treatment time and temperature and the amount of Ca addition. The edges of crack-like pore parallel to <1100> direction in (001) basal plane were stable but the edges normal to this direction in (00101) plane <1120> direction were unstable to facetting This means that the surface energy of alumina along the <1100> direction in (0001) basal plane in much lower than <1120> direction.

• 신재생에너지
• /
• 제10권4호
• /
• pp.29-35
• /
• 2014

Non-used waste heat has recently been paid special attention due to several global warming regulation and energy cost rising. In this study, therefore, thermal energy storage system which uses a solid type heat media has been investigated about the possibility of heat accumulation and heat release for thermal energy storage system. 35kWh of bench-scale thermal storage system was used to investigate the characteristics of the solid type heat media. From the result, it is shown that a solid type heat media should be divided to supply constant heat to the customers' side. It is also shown the flow direction should be considered to reduce temperature difference between top and bottom sides in the thermal storage system.

• 대한기계학회논문집A
• /
• 제25권7호
• /
• pp.1155-1162
• /
• 2001

Sihs minimum strain energy density criterion(SED) often used in the mixed mode problem has the ambiguity of the choice of minimum values. In this paper, as the method to solve the problem of SED, maximum minimum strain energy density criterion is proposed that the crack propagates in the direction of having the maximum among the minimum values of modified strain energy density factor(MS), i.e., sign($\sigma$(sub)$\theta$).Smin.

• 천문학회보
• /
• 제39권1호
• /
• pp.32.1-32.1
• /
• 2014

Astronomical observations strongly suggest that the expansion rate of our universe is currently under acceleration. The nature of the so-called dark energy causing the acceleration is unknown, and it is one of the fundamental mysteries in the present day theoretical cosmology. Here we briefly review the current state of cosmic dark energy research in both theoretical and observational sides. Constraints on dynamical dark energy models (e.g., w-fluid, quintessence, and modified gravity) with recent observational data from type Ia supernovae, cosmic microwave background radiation, and large-scale structures in the universe indicate a preferred direction toward the simplest ${\Lambda}$CDM world model. We also discuss some issues regarding the early dark energy model and the spherical collapse of matter in the presence of dark energy.

• 한국태양에너지학회 논문집
• /
• 제23권2호
• /
• pp.35-41
• /
• 2003

In order to investigate the offshore wind resources around Korean peninsula, the "QuikSCAT Level 3" data by ADEOS II satellite was analyzed from Jan 1 2000 to Jan 18 2003. The "SeaWinds" on the satellite is a specialize4 device for microwave scatterometery that measures near-surface wind speed and direction under all weather and cloud conditions. Wind speed are extrapolated from 10m to 60m with the exponent of 1/10 in the power law model. It has been found that the High wind energy potentials are prevailing in the South sea and Southeastern end of Korean peninsula.

• Nuclear Engineering and Technology
• /
• 제53권5호
• /
• pp.1723-1729
• /
• 2021

Energy and directional distribution of neutrons at the Beloyarsk NPP workplaces is a subject of this study. Measurements of H^*(10) rate and neutron energy distribution were taken at 8 workplaces, which can be divided into three categories: work with spent or fresh nuclear fuel, work with radionuclide neutron sources, work at the rooms adjusted to reactors. The Hp(10) measurements were performed only at 6 out of 8 locations, due to the fact that long term placing of an effective neutron moderator in fresh nuclear fuel storage facility is forbidden. As a result of the research energy and direction distribution of the neutron fields at 8 locations of the Beloyarsk NPP workplaces was obtained. To estimate the accuracy of the H^*(10) rate and Hp (10) measurements the reference values of dose equivalents were calculated using energy and directional distribution. To take into account the difference between the reference values and the measured results site-specific correction factors were calculated.

• 가족자원경영과 정책
• /
• 제7권1호
• /
• pp.91-101
• /
• 2003

The research examines individual environmental characteristics, the consciousness energy conservation and behavior level of college students that relate to the experience of taking courses on residential energy use held in college, as well as the influence of experiencing school education in the past. This is to ultimately evaluate the effect of school education on the consciousness of the energy conservation and behavior level of college students at present time, in order to assist in proposing a direction for the school education on residential energy use. The results of the research can be summarized as follows: First, there appeared a gap between the group that has attended courses on residential energy use and the group that has not in terms of their major, school year and the level of consciousness of the need for energy conservation. Second, students that have attended courses on residential energy use in college were reported to have received more training in high school through textbooks and guidance of teachers and have more experience in special education. And third, it appeared that taking courses in residential energy use by college students are influenced by personal factors such as their school year and gender, major, contents of their high school textbooks and the level of consciousness of the need for energy conservation.

• 세라미스트
• /
• 제22권1호
• /
• pp.56-69
• /
• 2019

Recent advances in low-power sensors and transmitters are driving the search for standalone power sources that utilize unused ambient energy. These energy harvesters can alleviate the issues related to the installation and maintenance of sensors. Particularly piezoelectric energy harvesters, with the ability to convert ambient mechanical energy into useful electricity, have received significant attention due to their high energy density, low cost and operational stability over wide temperature and pressure conditions. In order to maximize the generated electrical power, the natural frequency of the piezoelectric energy harvester should be matched with the dominant frequency of ambient vibrations. However, piezoelectric energy harvesters typically exhibit a narrow bandwidth, thus, it becomes difficult to operate near resonance under broadband ambient vibration conditions. Therefore, the resonating of energy harvesters is critical to generate maximum output power under ambient vibration conditions. For this, energy harvesters should have broadband natural frequency or actively tunable natural frequency with ambient vibrations. Here, we review the most plausible broadband energy harvesting techniques of the multi-resonance, nonlinearity, and self-resonance tuning. The operation mechanisms and recent representative studies of each technique are introduced and the advantages and disadvantages of each method are discussed. In addition, we look into the future research direction for the broadband energy harvester.