• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.109-113
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• 2011

Hot air flow simulations of the wet station dryer module for the solar cell cleaning were conducted. Air incident angles such as to the substrates ($45^{\circ}$), to the bottom ($90^{\circ}$), and to the wall ($135^{\circ}$) were considered. Based on the simulated velocity and temperature profiles, appropriate incident angle was proposed, and it was well matched to experimental results. Additionally, uniform and non-uniform air hole sizes of the tube were compared for the uniform air flow distribution through the batch.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.11
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• pp.1806-1816
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• 2009

This study analyzes the efficiency of a solar cell attached to an air circulation jacket. A commercially available silicon solar panel was selected and attached at four spots where the body angle was $40-60^{\circ}$ and voltage ($V_{oc}$, V), current ($I_{sc}$, A), and output power (P, W) were measured to determine the efficiency. The solar panel was applied to the outer jacket that operates with two fans to increase the convection that lowers the body temperature. The heavy work of standing, walking, and sweeping of a street sweeper was simulated in the field test. The microclimate within the jacket (with or without a fan) was measured and the subjective thermal, humidity, and comfort sensations were surveyed. SPSS 12.0 statistical package was used for a t-test and Wilcoxon signed-rank test. The results show that the highest efficiency of the solar cell was at the incident angle of $60^{\circ}$ in terms of voltage, current and output power distribution. The microclimate temperature of the air circulation jacket decreased significantly with the high power of the fan and subjects felt cooler than the jacket with a fan at the incident angle of $60^{\circ}$. Air circulation jackets operated by a silicon solar panel showed a significant cooling effect on the wearers.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.174-174
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• 2014

Memristor devices are one of the most promising candidate approaches to next-generation memory technologies. Memristive switching phenomena usually rely on repeated electrical resistive switching between non-volatile resistance states in an active material under the application of an electrical stimulus, such as a voltage or current. Recent reports have explored the use of variety of external operating parameters, such as the modulation of an applied magnetic field, temperature, or illumination conditions to activate changes in the memristive switching behaviors. Among these possible choices of signal controlling factors of memristor, photon is particularly attractive because photonic signals are not only easier to reach directly over long distances than electrical signal, but they also efficiently manage the interactions between logic devices without any signal interference. Furthermore, due to the inherent wave characteristics of photons, the facile manipulation of the light ray enables incident light angle controlled memristive switching. So that, in the tautological sense, device orienting position with regard to a photon source determines the occurrence of memristive switching as well. To demonstrate this position controlled memory device functionality, we have fabricated a metal-semiconductor-metal memristive switching nanodevice using ZnO nanorods. Superhydrophobicity employed in this memristor gives rise to illumination direction selectivity as an extra controlling parameter which is important feature in emerging. When light irradiates from a point source in water to the surface treated device, refraction of light ray takes place at the water/air interface because of the optical density differences in two media (water/air). When incident light travels through a higher refractive index medium (water; n=1.33) to lower one (air; n=1), a total reflection occurs for incidence angles over the critical value. Thus, when we watch the submerged NW arrays at the view angles over the critical angle, a mirror-like surface is observed due to the presence of air pocket layer. From this processes, the reversible switching characteristics were verified by modulating the light incident angle between the resistor and memristor.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.19-30
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• 1995

Diffraction patterns of the copolarized and the crosspolarized total electric fields by a spherical air cavity in a dielectric medium are analyzed in the forward near-field region when the wavelength of the incident plane wave is comparable to one half of the cavity radius. It is shown that double nulls and dips of the copolarized and the crosspolarized total electric fields exist in the measurement plane tansverse to the propagating direction of the incident field, and their dependences on the frequency, the distance of the measurement plane, and the measurement angle are analyzed.

• Journal of KSNVE
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• v.7 no.6
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• pp.945-952
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• 1997

This paper shows the feasibility of the suggestion that the angle distribution of incident sound to panels might be gaussian, instead of the conventional uniform distribution in the analysis of transmission loss of panels. To prove the suggestion, the problems with the diffuse sound field in a reverberation room are examined by case studies and the comparision of the prediction with the measurement of sound transmission loss of walls are performed. The results of the comparision show good agreement between the two values.

• ETRI Journal
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• v.25 no.1
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• pp.41-48
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• 2003

This paper presents a theoretical investigation of power reflection and transmission coefficients for a meander-line polarizer placed periodically on a chiral slab. It is assumed that a linearly polarized transverse magnetic wave is incident on a chiral slab from the air region. In the analysis, we derive the electric and magnetic fields in the modal form in the air and chiral regions. We obtain power reflection and transmission coefficients in a straightforward manner after matching the tangential components of the electric and magnetic fields at the boundaries. We present numerical results for the power reflection and transmission coefficients versus frequency and incident angle for different values of the chirality admittance. A meander-line polarizer placed on a dielectric slab can convert a linearly polarized wave to a circularly polarized wave. The design parameters for a meander-line polarizer are the dimensions of the meander-line and the values of the dielectric slab. Replacing a dielectric slab with a chiral slab introduces a new independent parameter which controls the wave polarization.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.296-296
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• 2014

We investigate experimentally and theoretically the splitting of surface plasmon (SP) resonance peaks under TE- and TM-polarized illumination. The SP structure at infrared wavelength is fabricated with a 2-dimensional square periodic array of circular holes penetrating through Au (gold) film. In brief, the processing steps to fabricate the SP structure are as follows. (i) A standard optical lithography was performed to produce to a periodic array of photoresist (PR) circular cylinders. (ii) After the PR pattern, e-beam evaporation was used to deposit a 50-nm thick layer of Au. (iii) A lift-off processing with acetone to remove the PR layer, leading to final structure (pitch, $p=2.2{\mu}m$; aperture size, $d=1.1{\mu}m$) as shown in Fig. 1(a). The transmission is measured using a Nicolet Fourier-transform infrared spectroscopy (FTIR) at the incident angle from $0^{\circ}$ to $36^{\circ}$ with a step of $4^{\circ}$ both in TE and TM polarization. Measured first and second order SP resonances at interface between Au and GaAs exhibit the splitting into two branches under TM-polarized light as shown in Fig. 1(b). However, as the incidence angle under TE polarization is increased, the $1^{st}$ order SP resonance peak blue-shifts slightly while the splitting of $2^{nd}$ order SP resonance peak tends to be larger (not shown here). For the purpose of understanding our experimental results qualitatively, SP resonance peak wavelengths can be calculated from momentum matching condition (black circle depicted in Fig. 2(b)), $k_{sp}=k_{\parallel}{\pm}iG_x{\pm}jG_y$, where $k_{sp}$ is the SP wavevector, $k_{\parallel}$ is the in-plane component of incident light wavevector, i and j are SP coupling order, and G is the grating momentum wavevector. Moreover, for better understanding we performed 3D full field electromagnetic simulations of SP structure using a finite integration technique (CST Microwave Studio). Fig. 1(b) shows an excellent agreement between the experimental, calculated and CST-simulated splitting of SP resonance peaks with various incidence angles under TM-polarized illumination (TE results are not shown here). The simulated z-component electric field (Ez) distribution at incident angle, $4^{\circ}$ and $16^{\circ}$ under TM polarization and at the corresponding SP resonance wavelength is shown in Fig. 1(c). The analysis and comparison of theoretical results with experiment indicates a good agreement of the splitting behavior of the surface plasmon resonance modes at oblique incidence both in TE and TM polarization.

• Proceedings of the Korean Fiber Society Conference
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• 1996.10a
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• pp.29-34
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• 1996

In the present paper, the flow distribution in the hot air drying chamber of a sizing machine was numerically analyzed with respect to the geometries of the intake duct to obtain the more uniform flow distribution in the chamber. The result shows that the velocity distribution in the inlet of the chamber was significantly dependent on the the geometry of the intake duct. The degree of the non-uniformity in the chamber was reduced as the incident angle of the intake duct became to be smaller.

• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.515-520
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• 2002

The variation of the optical pass length between incident and reflective beam in a multilayer thin film reflection mirror is investigated. This variation is caused mainly by environmental parameters around the optical system, such as the air pressure, temperature, humidity and $CO_2$concentration. In this paper, a new method for measuring optical pass length variation is proposed. This optical pass length is measured against the above parameters by experiment. From the experimental results, it is clarified that the optical pass length is mostly effected by humidity changes.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.67-73
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• 2009

This study presents the results of a slamming experiment using a pneumatic cylinder. The employment of the pneumatic cylinder showed a relatively good repeatability when the results were compared with those of other slamming devices. The experiment was done for various incident angles. An air pocket was believed to cause a reduction in the magnitude of the impact pressure with an incident angle of $0^{\circ}$ for the water entry. A high speed camera was used in an attempt to locate the time of the contact between the bottom of the specimen and the free surface. It seemed that the maximum pressure occurred before the water contacted the bottom of the specimen.