육성한 화단국화 품종인 황색 국화(Chrysanthemum morifolium Ramat.)인 ‘한아름볼(Hanarum Ball)’은 충남농업기술원 화훼 연구소에서 모본 ‘Gigi Gold’와 부본 ‘Jinny Ball’을 이용하여 육성되었다. ‘한아름볼’ 품종은 2014년에 인공 교배를 통해 개 발되었으며, 2015년부터 2017년까지 품종 특성을 조사한 후 2017년에 최종 선발되었다. ‘한아름볼’의 초형은 반구형으로, 노랑색 꽃잎(Yellow 5B)을 가진 반겹꽃을 지니고 있으며, 개화 기는 9월 21일이다. 초장은 36.0cm로, 초폭은 66.0cm, 화폭 은 4.1cm, 본당 착화수는 1,147개, 꽃잎수는 81.0개이며, 엽색 은 녹색(Green 137B)이어서, 대조품종인 ‘금방울’과 유사한 형 태와 색을 가지고 있으나, 꽃크기와 착화수, 개화시기에서 차이 를 보였다. ‘한아름볼’은 도로변이나 화단 등 조경용으로 활용 가능하며, 화훼 농가에 새로운 소득원을 제공할 수 있는 품종으 로 기대된다.

Ceramic materials have become essential due to their high durability, chemical stability, and excellent thermal stability in various advanced industries such as aerospace, automotive, and semiconductor. However, high-performance ceramic materials face limitations in commercialization due to the high cost of raw materials and complex manufacturing processes. Aluminum borate (Al₁₈B₄O₃₃) has emerged as a promising alternative due to its superior mechanical strength and thermal stability, despite its simple manufacturing process and low production cost. In this study, we propose a method for producing Al₁₈B₄O₃₃ spherical powder with increased uniformity and high flowability by controlling the particle size of B₂O₃. The content ratio of the manufactured Al18B4O33 spherical powder was Al2O3: B2O3 = 87:13, and it exhibited a 17% reduction in the Hausner ratio (1.04) and a 29% decrease in the angle of repose (23.9°) compared to pre-milling conditions, demonstrating excellent flowability.

In March 2022, Wongu-ilyeong, a globe-like sundial made during the 19th century in the Joseon Dynasty, was repatriated from the United States through the efforts of the Korea Heritage Service and the Overseas Korean Cultural Heritage Foundation. This sundial has a total height of about 228 mm, and has time lines and a T-shaped gnomon on its spherical surface with a diameter of approximately 112.2 mm. This sundial is known to have been made by Sang Jik-Hyeon (尙稷鉉, 1849–?), as he carved his seal and the manufacturing date onto its spherical surface. This study investigated Sang, Jik-Hyeon's records from royal governmental literature, and also analyzed the structure of Wongu-ilyeong to understand its usage. We restored the Wongu-ilyeong’s design drawing and manufactured a prototype, with which we measured daytime hours in Jeju, Daejeon, and Seoul. The experimental measurements from three cities showed that the time accuracy of the Wongu-ilyeong, whose minimum time scale is 15 minutes, could be measured within ±7.5 minutes. Wongu-ilyeong is a very rare type of sundial-relic in Korea and overseas, and it is considered to have significant value in the history of science and technology.

We study quasi-spherical, supersonic accretion flows around black holes using high-accuracy numerical simulations. We describe a code, the Lagrangian Total Variation Diminishing (TVD), and a remap routine to address a specific issue in the Advection Dominated Accretion Flow (ADAF) that is, appropriately handling the angular momentum even near the inner boundary. The Lagrangian TVD code is based on an explicit finite difference scheme on mass-volume grids to track fluid particles with time. The consequences are remapped on fixed grids using the explicit Eulerian finitedifference algorithm with a third-order accuracy. Test results show that one can successfully handle flows and resolve shocks within two to three computational cells. Especially, the calculation of a hydrodynamical accretion disk without viscosity around a black hole shows that one can conserve nearly 100% of specific a ngular momentum in one-and twodimensional cylindrical coordinates. Thus, we apply this code to obtain a numerically similar ADAF solution. We perform simulations, including viscosity terms in one-dimensional spherical geometry on the non-uniform grids, to obtain greater quantitative consequences and to save computational time. The error of specific angular momentum in Newtonian potential is less than 1% between r~10rs and r~10 4 rs, where rs is sink size. As Narayan et al. (1997) suggested, the ADAFs in pseudo-Newtonian potential become supersonic flows near the black hole, and the sonic point is rsonic~5.3rg for flow with α =0.3 and  =1 .5. Such simulations indicate that even the ADAF with  =5/3 is differentially rotating, as Ogilvie (1999) indicated. Hence, we conclude that the Lagrangian TVD and remap code treat the role of viscosity more precisely than the other scheme, even near the inner boundary in a rotating accretion flow around a nonrotating black hole.

As the size of the gaming market continues to grow, game engines like Unity and Unreal are constantly being developed and updated for multi-platform support. In particular, Unity divides the Render Pipeline to be used. Among them, the Universal Render Pipeline (URP) has the advantage of supporting various platforms while improving performance by reducing draw calls and batches at the same quality settings and reducing the load on the CPU and GPU. However, only limited global illumination is supported in the real-time 3D rendering area within URP, such as Baked GI and Enlighten GI, and Enlighten GI will be deprecated after 2024LST, so real-time global illumination is not available in URP, which may reduce the realism and immersion of global illumination in games or applications that use URP. The main objective of this research is to incorporate precomputed spherical harmonics into URP to enable dynamic GI updates in real-time. The approach proposed in this research is to compute the coefficients of spherical harmonics offline and then run them within the URP rendering pipeline, where work exists to effectively simulate dynamic lighting conditions. To demonstrate this, experiments were conducted by changing the rotation and color of the lights, and a comparative analysis was performed to demonstrate the effectiveness of the theory proposed in this work.

The theoretical capacity of silicon-based anode materials is more than 10 times higher than the capacity of graphite, so silicon can be used as an alternative to graphite anode materials. However, silicon has a much higher contraction and expansion rate due to lithiation of the anode material during the charge and discharge processes, compared to graphite anode materials, resulting in the pulverization of silicon particles during repeated charge and discharge. To compensate for the above issues, there is a growing interest in SiOx materials with a silica or carbon coating to minimize the expansion of the silicon. In this study, spherical silica (SiO2) was synthesized using TEOS as a starting material for the fabrication of such SiOx through heating in a reduction atmosphere. SiOx powder was produced by adding PVA as a carbon source and inducing the reduction of silica by the carbothermal reduction method. The ratio of TEOS to distilled water, the stirring time, and the amount of PVA added were adjusted to induce size and morphology, resulting in uniform nanosized spherical silica particles. For the reduction of the spherical monodisperse silica particles, a nitrogen gas atmosphere mixed with 5 % hydrogen was applied, and oxygen atoms in the silica were selectively removed by the carbothermal reduction method. The produced SiOx powder was characterized by FE-SEM to examine the morphology and size changes of the particles, and XPS and FT-IR were used to examine the x value (O/Si ratio) of the synthesized SiOx.

The spherical mesophases are the main precursors for the high tap density of carbonaceous anode batteries. However, it is challenging to control mesophase size without coalescence and no deformation since it quickly coalesces into a regular large sphere. Here, we propose a feasible extraction method to refine the spherical size of mesophase using benzene. Thermogravimetric and differential scanning calorimetry analysis of untreated pitch revealed that the maximum temperature for mesophase nucleation should not exceed 410 °C to provoke the nucleation of mesophase spheres while maintaining a high pyrolysis yield. The extraction results showed that the extraction weight tends to decrease with an increase in the solvent ratio. There is an exponential relationship between the influence of solvent ratio and the ability for extraction. The solubility of the spherical mesophase in benzene is size-dependent and can dissolve selectively spherical mesophases smaller than 5 μm. Consequently, a monodisperse spherical mesophase was obtained. The reason for forming uniform mesophase spheres can be explained by their thermodynamic state, as described by the “two-step” classical nucleation theory. Benzene effectively improves the size distribution of spherical mesophase by dissolving small sizes while retaining large ones.

With the advancement of optical design and manufacturing technology, optical components have found diverse applications, spanning from semiconductors to the aerospace industry. A reflective mirror is a basic component in optics and plays a crucial role as the medium to reflect light. In this paper, a large mirror with a 700mm diameter was designed as a primary mirror using fused silica. The rear side of the mirror was subdivided into several equal angles, and neighboring vertices on the circumference were connected to establish a polygon. Accordingly, the geometric shapes of triangle, square, pentagon, and hexagon were formed. Furthermore, the mirror structure was strengthened by employing straight lines passing the vertices and the center of the circle. Based on the finite element analysis, deformations of the mirrors caused by the gravitational force were evaluated. Weight and deformation of the mirror structures were compared and analyzed to find a proper structure to reduce weight and deformation. This paper, therefore, presents a structural solution aimed at reducing the weight and deformation of a large aperture mirror induced by gravitational forces, thereby suggesting a geometric shape based structure to reduce surface deformation of a mirror.

In general, a large mirror without weight reduction in large optical or space telescope systems can increase the system’s weight or lead to significant deformation of the mirror surface. Thus, it is imperative to pursue lightweight design strategies. In this paper, the structure design of a spherical mirror, a diameter of 600mm and a mirror radius of 2,000mm, was investigated to reduce weight and minimize deformation. To establish load paths for internal and external loads, stiffeners were added across the lateral supports. This approach effectively reduced both weight and deformation caused by gravity. Weight reduction and reduction percentages were quantified, and the mirror deformation was evaluated by using finite element analysis (FEA). The proposed structures were compared with honeycomb structures for weight reduction. This evaluation allowed to assess the deformation characteristics and the potential advantages of the proposed structures for lightweight mirrors.

YAG phosphor powders were fabricated by the atmospheric plasma spraying method with the spray-dried spherical YAG precursor. The YAG precursor slurry for the spray drying process was prepared by the PVA solution chemical processing utilizing a domestic easy-sintered aluminum oxide (Al2O3) powder as a seed. The homogenous and viscous slurry resulted in dense granules, not hollow or porous particles. The synthesized phosphor powders demonstrated a stable YAG phase, and excellent fluorescence properties of approximately 115% compared with commercial YAG:Ce3+ powder. The microstructure of the phosphor powder had a perfect spherical shape and an average particle s ize of a pprox imately 30 μm. As a r esult of t he PKG t est of t he YAG p hosphor p owder, t he s ynthesized phosphor powders exhibited an outstanding luminous intensity, and a peak wavelength was observed at 531 nm.

Zerodur, one of the optical materials, was used for large spherical mirrors in this study. For weight reduction, several types of honeycomb structures were investigated. The finite element simulation was used for deformation and mode analysis. It was revealed that the weight reduction rate and maximum deflection due to the gravity effect vary depending on the honeycomb structures. Additionally, this study highlights the potential of spline-shaped honeycomb structures as an alternative for weight reduction, and triangular honeycomb structures demonstrated the less deformation by the gravity effect. The findings from this study provide valuable insights for designing lightweight and high-performance spherical mirrors in optical systems.

In this research, the a novel finishing machine was used for hight-precision surface of spherical ball products that have been widely used for on/off valve for hydrogen energy flowing system and in medical field such as artificial hip joint component. The spherical balls products are the workpiece that made by Co-Cr-Mo alloys with 32-mm in diameter and Sa≈ 0.30μm in surface roughness. Their surface roughness was successfully improved via the magnetic abrasive tools that controlled the magnetic field of permanent magnets. The critical input conditions were selected as rotational speed: 800rpm, gap: 3mm, tool grain size: 1-μm finishing time: 0, 3, 6, 9, 12, and 15min. The results of this research showed that under the given finishing conditions, the high surface quality in the terms of surface precision of spherical ball products are successfully achieved, in which the surface roughness is reduced from 0.30-μm to 0.04-μm within the short finishing time at 12min. Therefore, it can be concluded that a novel finishing machine is feasible to be used for improving the surface roughness of spherical ball products, resulted in high surface precision of materials.

목적: 초기노안을 대상으로 중심-근용 멀티포컬 콘택트렌즈 착용 시 구면수차가 시력에 미치는 영향을 확인하고자 하였다. 방법 : 초기노안 50명을 대상으로 중심-근용 멀티포컬 콘택트렌즈 착용하고 일주일의 적응 기간 후 원·근거 리 시력과 구면수차의 변화 및 원·근거리 시력 개선에 필요한 추가 교정도수를 확인하였고, 시력만족도는 설문조 사로 확인하였다. 결과 : 대상자의 평균 교정굴절력은 –2.65±1.67 D, 가입도는 +1.15±0.05 D이었으며, 안구 구면수차는 0.010±0.028 ㎛였으며, 이 중 37명(72 %)은 양의 구면수차(0.028±0.017 ㎛)를, 13명(28 %)은 음의 구면수차 (–0.020±0.010 ㎛)를 갖고 있었다. 중심-근용 멀티포컬 콘택트렌즈를 착용한 후 양의 구면수차를 가 진 그룹은 -0.012±0.005 ㎛로, 음의 구면수차를 가진 그룹은 –0.043±0.010 μm로 모두 음(-)의 방향으로 증 가하였다(p<0.050). 멀티포컬 콘택트렌즈를 착용한 후 100% 원거리 시력(logMAR)은 양의 구면수차를 가진 그룹 에서는 –0.014±0.090, 음의 구면수차를 가진 그룹에서는 0.022±0.120으로 양의 구면수차를 가진 그룹에서 더 좋았고(p<0.001), 100% 고대비 근시력(logMAR)은 양의 구면수차를 가진 그룹에서는 0.127±0.090, 음의 구면 수차를 가진 그룹에서는 0.118±0.090으로 음의 구면수차를 가진 그룹에서 더 좋았다(p<0.001). 설문조사 결과 에서는 양의 구면수차를 가진 그룹에서는 원거리에서 높은 만족도를 보였고, 음의 구면수차를 가진 그룹에서는 중 간거리와 근거리 영역에서 만족도가 높았다(p<0.050). 결론 : 중심-근용 멀티포컬 콘택트렌즈를 처방 후 구면수차가 변할 수 있고, 착용자의 안구 구면수차에 따라 원·근거리 시력 만족도가 달라질 수 있음을 확인하였다. 따라서 멀티포컬 콘택트렌즈를 처방할 때 착용자의 구면 수차를 확인한다면 처방 성공률을 더 높일 수 있을 것으로 사료된다.

We report the behaviour of carbon black (CB) nanoparticles (spherical carbon shells), subjected to external pressure, using diamond anvil cell at synchrotron facility. CB nanoparticles have been synthesized by lamp black method using olive oil as combustion precursor and ferrocene as an organometallic additive. The catalyst-assisted CB has an iron oxide (γ-Fe2O3) core and amorphous carbon shell (i.e. core–shell structure). Our present study suggests that the carbon shells are partially transparent to the applied high pressure, and result in the reduction of effective pressure that gets transferred to the iron oxide core. High-pressure Raman spectroscopy results indicate that the surrounding carbon shells get compressed with pressure and this change is reversible. However, no structural transformation was observed till the highest applied pressure (25 GPa). The Raman spectroscopy results also suggests that the carbon shells are less pressure sensitive as their pressure coefficients (dω/dP) of G-peak were calculated (3.79 cm− 1/GPa) to be less than that for other carbon allotropes.

Non-verbal communication is important in human interaction. It provides a layer of information that complements the message being transmitted. This type of information is not limited to human speakers. In human– robot communication, increasing the animacy of the robotic agent—by using non-verbal cues—can aid the expression of abstract concepts such as emotions. Considering the physical limitations of artificial agents, robots can use light and movement to express equivalent emotional feedback. This study analyzes the effects of LED and motion animation of a spherical robot on the emotion being expressed by the robot. A within-subjects experiment was conducted at the University of Tsukuba where participants were asked to rate 28 video samples of a robot interacting with a person. The robot displayed different motions with and without light animations. The results indicated that adding LED animations changes the emotional impression of the robot for valence, arousal, and dominance dimensions. Furthermore, people associated various situations according to the robot’s behavior. These stimuli can be used to modulate the intensity of the emotion being expressed and enhance the interaction experience. This paper facilitates the possibility of designing more affective robots in the future, using simple feedback.