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It has been reported that the scattering cross-sections of resonance Raman spectra strongly depend on the resonance between the laser's excitation energy and the electronic absorption band of pigments in solution. However, the actual collection of scattered photons is affected by diffuse scattering and self-absorption when studying painted colorants in artworks. Quantitative spectroscopic measurements are required to elucidate the apparent resonance Raman cross-sections in both solution and solid. In this study, we explored the excitation-dependent Raman scattering of natural and artificial Korean pigments painted on a wood block with six visible wavelengths. Our study shows that the Raman intensity profile agrees with the emission profile rather than with the absorption. We also assessed the validity of self-absorption and the outgoing resonance mechanism in the solid state for the results.

In situ real-time and nondestructive identification of packaged chemicals is essential for applications such as homeland security and terrorism prevention. Although various Raman spectroscopic methods such as spatially offset Raman spectroscopy (SORS) and time-resolved Raman spectroscopy have been investigated for real-time detection, the background interference originating from packaging materials limits the accuracy of the analysis. In principle, the Raman background from the packaging cannot be removed completely. To overcome this limitation, we developed a SORS-based dual-offset optical probe (DOOP) system that offers real-time prediction of 20 chemicals concealed in various containers by completely removing the background signal. The DOOP system selectively acquires the Raman photons generated from both the outer packaging and the inner contents, whose intensities are dependent on the penetration depth of the laser. The Raman spectra obtained at two remote offsets are automatically subtracted after normalization. We demonstrate that the DOOP method provides the pure component spectra by completely removing background interference from three plastic containers for a total of 20 samples in three different containers. In addition, an artificial neural network (ANN) was applied to evaluate the accuracy of the real-time chemical identification system; our system led to drastic improvements of the ANN prediction accuracy.

The purpose of this research is to clarify the architectural features of young-dang 影堂 (‘portrait-hall’) buildings during the Joseon Dynasty, based on the changes in ritual spaces related to Confucianism and Buddhism. Young-dang is a place where the portrait of a given person is enshrined. In Confucian ritual tradition, a pavilion where an ancestor’s ‘spirit tablet’ is enshrined is called sadang 祠堂 or myo 廟. However, when the enshrined object is a portrait, young-dang starts to become something distinct from the original Confucian tradition. If the portrait is a sort of figure, it starts to be more concerned with Buddhist ritual tradition. According to the literary work Goryeosachoryo 高麗史節要, young-dang had been thriving during the late Goryeo 高麗 dynasty. After the dynasty changed to Joseon 朝鮮, Confucian rituals were encouraged while Buddhist rituals were officially prohibited. In spite of this ideological transition, young-dang architecture kept being built until the late Joseon dynasty. Since the ritual ceremonies carried out in young-dang were made to fit with Confucian tradition, the architectural features of young-dang are immediately related to the Confucian pavilion. However, the enshrined object has a close relationship with Buddhist ritual tradition. These ritual spaces of the Joseon dynasty gradually changed since they were first introduced from China. The overall trend towards changing usage patterns, which are based on aspects of architectural features and ritual traditions that came from both Confucian and Buddhist architecture, also seems to have influenced the architecture of young-dang.

This study empirically investigates the effect of a CEO turnover on audit report lag (ARL), discretionary report lag (DRL) and total report lag (TRL). The object of this study is to provide empirical evidence for the responses of both the CEO and the external auditor on audit risk increases and information asymmetry that occur as a result of a CEO turnover. According to the previous study on CEO turnovers, the CEO turnover would increase audit risk and information asymmetry (Sohn et al., 2014). In this situation, the CEO has an incentive to provide timely information to decrease the monitoring costs and cost of debt (Lee et al., 2008). It is expected that an external auditor spends a large amount of time on audit procedures to lower the audit risk when the CEO changes. Therefore, the CEO turnover would have a conflicting effect on the ARL and DRL. The results of the analysis are as follows. First, the ARL increases and DRL decreases when the CEO changes, which suggests that an external auditor spends a great amount of time on audit procedures to lower the audit risk because the audit risk increases when the CEO changes. A new CEO provides information faster to reduce monitoring costs and cost of debt that occur due to information asymmetry. Second, the ARL increases and DRL decreases as the frequency of CEO turnover increases. An external auditor would estimate the audit risk as being high if the CEO changes more frequently. To lower the audit risk to an acceptable level, many audit hours are spent on audit procedures by an external auditor, which increases the ARL. A new CEO has an incentive to provide timely information when the CEO changes more frequently. Thus, the DRL decreases as the frequency of CEO turnover increases

The purpose of this research is to reconstruct the Dongho Dokseodang and to examine its architectural characteristics in the mid-Joseon period. This institution was established for the Sagadoksseo(賜暇讀書), which is similar to the sabbatical year today. In 1517, it was first constructed and such buildings as the Jeongdang(正堂), Buok(附屋), Namru(南樓) and Seosangbang(西上房) were built at the time. In 1551, Munhoedang(文會堂) and Hanggak(行閣) were newly added, and in 1587 a new hall was built around a lotus pond. With the Imjin war in 1592, however, all buildings were devastated. There remain primary sources such as paintings and literatures providing the architectural information of the institution at the time. Based on these sources, various scholarly attempts to reconstruct the institution have been made since 2003. In this research, the primary sources and preceding stuides will be reviewed to reach a more reasonable reconstruction of the Dongho Dokseodang. In doing so, its important architectural characteristics are discussed as well.

In this paper, a clock-data recovery using a 1/8-rate phase detector is proposed. The use of a conventional full or half-rate phase detector requires relatively higher frequency of a recovered clock, which is a burden on the design of a sampling circuit and a VCO. In this paper, a 1/8-rate phase detector is used to lower the frequency of the recovered clock and a linear equalizer is used as a input circuit of a phase detector to reduce the jitter of the recovered clock. A test chip fabricated in a 0.13- CMOS process is measured at 1.5-GHz for a 3-Gb/s PRBS input and 1.2-V power supply.

A 6-Gb/s differential voltage mode driver is presented whose output impedance and pre-emphasis level can be controlled independently. The voltage mode driver consists of five binary-weighted slices each of which has four sub-drivers. The output impedance is controlled by the number of enabled slices while the pre-emphasis level is determined by how many sub-drivers in the enabled slices are driven by post-cursor input. A prototype transmitter with a voltage-mode driver implemented in a 65-nm CMOS logic process consumes 34.8-mW from a 1.2-V power supply and its pre-emphasized output signal shows 165-mVpp,diff and 0.56-UI eye opening at the end of a cable with 10-dB loss at 3-GHz.

In this study, normal and dichlorodicyanuric acid (DCCA)-treated wool slivers and yarns were immersed in a formic acid solution at elevated temperatures as a pre-treatment in order to accelerate the scale removal and fiber splitting of wool by ultrasonication and the effect of pre-treatment on the morphology and fiber splitting of wools was investigated. As the formic acid concentration, the treatment temperature, and the treatment time increased, the scale removal on wool fiber increased, however, the occurrence of felting and yellowing regarding wool fiber also increased indicating that the treatment with 50% formic acid at for 3 hours was the optimum pre-treatment condition for wool fiber. The SEM observation revealed that the formic acid treatment on wool at followed by ultrasonication was the effective tool in order to produce split fibers for both normal and DCCA-treated wool. The comparative study of sliver and yarn revealed that ultrasonication could lead to the fiber splitting of wool sliver whereas it could not result in that of wool yarn. On the other hand, formic acid treatment at resulted in fiber splitting for both wool sliver and yarn.

We fabricated hexagonal arrays of Co/Pt nanodots on Si surfaces by pulsed laser deposition (PLD) using cylindrically phase-separated polystyrene-b-poly(methylmethacrylate) (PS-b-PMMA) diblock copolymer thin films as templates after the removal of PMMA. The size and the separation of the nanodots were 23 and 40 nm, respectively, and the density of the nanodots was 1.5 x 10(11)/cm2. The magnetic properties of nanodot arrays measured by vibrating sample magnetometer were compared with those of PLD grown film. The films showed magnetic anisotropy with an easy axis in the in-plane direction, whereas no noticeable anisotropy was observed for nanodot arrays. In addition, the saturation magnetization (Ms) of both the Co/Pt nanodots and the film increased with the Pt content.

A simple synthesis route to high-quality sub-50 nm ZnO nanowires is reported, utilizing ZnO thin films grown by pulse laser deposition (PLD) as seed layers. Depending upon the PLD growth conditions, the surface morphology of the ZnO nanowires on ZnO film was distinctively different whereas the diameters were almost the same. With the increase of the concentration of zinc nitrate/methenamine solution from 0.002 to 0.02 M, the average diameter of the ZnO nanowire increased but remained sub-50 nm. The grown ZnO nanowires showed a high crystallinity with a low defect density confirmed by a sharp photoluminescence spectrum.

Ordered arrays of ZnO nanodots were fabricated by pulsed laser deposition (PLD) using an anodic aluminium oxide (AAO) nanopore membrane. Hexagonal-shaped ZnO nanodots with an average diameter of 60 nm and a periodicity of 100 nm were uniformly assembled into hexagonally ordered nanopores of the AAO membrane. Control of the oxygen pressure used in PLD resulted in a preferential photoluminescence (PL) at 380 nm from the ZnO nanodots: keeping the higher O2 pressure gave a dominant PL peak in the UV range over the visible range, which is attributed to the reduction of the number of oxygen vacancies.

We demonstrate the fabrication of metal and semiconductor nanodot arrays on Si by pulsed laser deposition using an anodic alumina membrane as a mask. A Hexagonal-close-packed nanopore membrane mask was fabricated by the anodic oxidation of aluminum sheet. Pulsed laser deposition of Ag, Ni, ZnO, and Er-doped Si (Si:Er) nanodots was performed on a Si substrate to which an alumina membrane mask adheres by van der Waals interaction. Highly ordered arrays of Ag, Ni, ZnO, and Si:Er nanodots with average diameters ranging from 55 to 86 nm and a periodicity of ~100 nm were obtained. Also, the time-resolved images of laser-produced plasma plumes were analyzed to examine the dynamical properties of the ejected materials.

In this study, we fabricated circular channels using photoresist reflow and isotropic etching. A silicon substrate, using Si3N4 as a mask, was selectively etched using the hydrofluoric acid, nitric acid, acetic acid (HNA) etching system for fabricating the bottom hemisphere of the channels. Photoresist reflow was used to make the top of the channels round. Then Si3N4 was deposited on the reflowed photoresist. Since the deposited Si3N4 was approximately 6000 A thick, it was possible to observe the inside of the channel. We expect to apply such circular channels to simple bio-systems and microfluidic devices in which optical detection is required.

We fabricated Er-doped silicon-rich silicon oxide (SRSO:Er) films by pulsed laser deposition. A Si+Er target consisting of an Er metallic strip and a silicon disk was adopted with a goal to achieve a convenient control of the Er and oxygen density in the film. We found that the photoluminescence (PL) at 1.54 μm is highly dependent on the ambient oxygen pressure, which determines the relative ratio of Si-Si, SiOx, and SiO2 phase in the film. The PL intensity increased drastically with increase in the annealing temperature and reached the maximum intensity at 500 °C.

Er-doped SiOx thin films were fabricated by laser ablation of a Si:Er2O3 target in He atmosphere. We have measured the photoluminescence (PL) at 1.54 μm for the films grown at different He pressures and found that the oxygen density of the grown film that strongly influences the PL intensity is highly correlated with the ambient He pressure. This manifests that oxygen density of the film can be controlled in an inert atmosphere to maximize PL intensity when we adopt pulsed laser deposition (PLD) technique to deposit Er-doped SiOx thin films. Also, we have examined the temperature dependence of PL and observed that the thermal quenching is greatly reduced for the PLD-grown films.

Mass spectral distributions and time-of-flight spectra of Cn+ (n=1–24) ions escaping from a carbon plasma plume generated by laser (λ=1064 nm) ablation of a graphite target are analyzed to shed light on their formation mechanisms, expansion dynamics, and laser–plume interaction. In particular, by shining the whole or a slice of the plume with a photodissociation laser (λ=266 nm) delayed with respect to the ablation laser, we examine the effects of the laser–plume interaction on the mass distribution as well as photodissociation channels of carbon-cluster cations. Also, we present experimental data that show a clear linear dependence of the velocities of Cn+ ions on 1/M. This result confirms that Cn+ ions are mainly accelerated by a transient local electric field in the plume.

Silver nanoparticles were synthesized by laser (Nd:YAG, λ =1064 nm) ablation of a silver target immersed in various concentrations of NaCl solutions as well as in neat water. The concentration dependence of the surface plasmon absorption at around 400 nm was examined by analyzing the absorbance and peak shape. Significant changes in the peak intensity and full width at half maximum (FWHM) were observed. Typically, the size of the silver nanoparticles produced in 5 mM NaCl solution ranged from 5 to 50 nm, with an average size of 26 nm. Also, fragmentation of silver nanoparticles by absorption of 355 nm laser light was found to be highly effective.

A digital lock detector capable of detecting frequency variations occurred during the operation of a digital filter of the detector is proposed. In this paper, the digital lock detector is applied to a dual loop PLL to give the frequency lock information to another PLL loop. The proposed lock detector with the PLL fabricated in a 0.13-µm CMOS process occupies 0.17-mm2 and consumes 35-mW from a 1.2-V power supply. The measured frequency offset between two VCOs is 0.16-%.

We have fabricated Er-doped amorphous SiOx films by laser ablation of a Si:Er2O3 target in He atmosphere. The photoluminescence intensity at 1.54 μm was highly dependent on the oxygen content in the film, which turned out to be changed significantly by the ambient He pressure. Also, we have adopted time-of-flight quadrupole mass spectroscopy to obtain kinetic energies of ionic species in a plume produced by laser ablation. Si and Er ions do not overlap spatially as they expand toward the Si substrate and Er ions impinge on the preformed SiOx layer.

SiOx (x2 atmosphere using Si target in a pulsed laser deposition system. Post-annealing process was employed in an O2 atmosphere to form the nanometer-sized Si crystallites embedded in the SiO2 films. The transmission electron microscope analysis shows the existence of crystalline silicon nano-dots with diameters ranging from 2 to 4 nm. Also, the clear separation of Si and SiO2 phases can be seen in the X-ray photoemission spectra. Photoluminescence peak from the annealed films was obtained, which is attributed to the quantum confinement effect of the Si nano-dots. C-V measurements of the metal-oxide-silicon (MOS) structure containing the silicon nano-dots in the oxide layer were performed to investigate the charging/discharging behavior of the silicon nano-dots. The maximum program window of the MOS was measured to be4.1V under ±5V sweep.

In this paper we have fabricated cylinder type micro channel using photoresist reflow and isotropic etching. Si substrate, using a Si/sub 3/N/sub 4/ (6000/spl Aring/) as a mask, was selectively etched using a HNA etching system for the bottom hemisphere of the channel. Photoresist reflow was used to make the top of the channel round. Then Si/sub 3/N/sub 4/ was deposited on the reflowed photoresist. Since the deposited Si/sub 3/N/sub 4/ was about 6000 /spl Aring/ thick it is possible to see the inside of the channel. This channel is expected to be applied to simple bio and microfluidic devices in which optical detection is needed.

This study investigated the relationship between CEO changes and information asymmetry. In the first year after a CEO change, management ability is evaluated in an atmosphere of high pressure and scrutiny regarding company performance. In such circumstances, CEOs selectively disclose information in an effort to inflate their performance evaluation. In addition, new CEOs influence not only management decisions, but also information disclosure strategies related to both financial and nonfinancial information. Therefore, the motivations of new CEOs regarding information disclosure can increase information asymmetry, and financial analysts must put extra effort toward reducing this asymmetry. This study measured information asymmetry by the unfaithful disclosure firm designation and analyst forecast errors. The sample is composed of firms active in the Korea Composite Stock Price Index (KOSPI) from 2006 to 2009. We found that there is a significant positive relationship between CEO change and information asymmetry as measured by unfaithful disclosure firm designation and analyst forecast errors. These results imply that CEO turnover increases information asymmetry due to managers intentional efforts to reduce the level of available information.

This study investigated the effects of the post-O2-annealing process on light emission from silicon nanocrystals. Using pulsed laser ablation in an O2-filled atmosphere, the SiOx (x

Photocurrent of a single ZnO nanowire synthesized by a sol-gel route was investigated. In vacuum, the dark current was bigger but the photoresponse was slower than that in air, attributed to the release of the available charge carriers by the desorption of water molecules and the decrease of the exchange rates of molecular ions. Under the steady radiation of the ultraviolet light (λ=325nm), a gradual decrease of the photocurrent was noticeable, which can be explained in terms of the annihilation of the carriers by the replacement of hydroxyl groups (OH−) by O2−, resulting in the decrease of charge carriers.

Ordered arrays of Er-doped Si nanodots were fabricated by pulsed laser deposition using an anodic aluminum oxide (AAO) nanopore membrane. Er-doped Si (Si:Er) nanodots with an average diameter of 60–80nm and a periodicity of 100nm were uniformly assembled into hexagonally ordered nanopores of AAO membrane. Photoluminescence (PL) spectra taken from Si:Er nanodots showed an emission peak at 1.54μm, which is due to intra-4f shell transition (I13∕24→I15∕24) of Er3+ ions. Postannealing of nanodot arrays up to 500°C resulted in the enhancement of PL intensities without enlargement or aggregation of the nanodots.

We have developed a new pulsed laser deposition method for fabricating Er-doped silicon-rich silicon oxide (SRSO:Er) films. A target composed of a pure Si disk and an Er metal strip was ablated by a line-focused laser beam in oxygen atmosphere. The oxygen concentration that determines the relative concentrations of the three phases (Si–Si, SiO x , and SiO2) in the film was easily controlled by varying the ambient oxygen pressure. The photoluminescence intensity at 1.54 µm from Er3+ ions was strongly dependent on the amount of the Si–Si phase in the SRSO:Er films.