• The Journal of Internal Korean Medicine
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• v.29 no.1
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• pp.117-129
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• 2008

Background & Objective : Naeso-san(NSS) has been used for the treatment of functional dyspepsia, regarded as a gastric dysmotility disease. A main cause of gastric dysmotility is antral dilatation or antroduodenal uncoordination. Therefore, we investigated the effect of NSS on gastric motility and its mechanism of action, as well as the morphologic changes in antral dilatated rats. Methods : Antral dilatated rats were induced by wrapping a nonabsorbable rubber ring(D:6mm, W:4mm, T:1mm) around the 1st portion of the duodenum for 8 weeks. Then morphologic changes were investigated and compared with normal intact rats before and after 8 weeks. Gastric emptying was measured by administration of normal saline(NS) or NSS in normal intact and antral dilatated rats. In another series of experiments to evaluate the mechanism of NSS under delayed conditions, normal intact rats were treated with atropine sulfate(1mg/kg, s.c.), quinpirole HCl(0.3mg/kg, i.p.), $NAME(N^{G}-nitro-L-arginine$ methyl ester, 75mg/kg, s.c.) and cisplatin(10mg/kg, i.p.), respectively. The myoelectrical activity of the gastric smooth muscle was recorded in normal intact and antral dilatated rats. The contractile waves were measured for 30 minutes before and after administration of each solution(NS, NSS). Results : Body weight gain of antral dilatated rats was significantly lower than that of the controls. Futhermore, we found the thickness of the mucosal and muscular layers and surface area of the stomach increased significantly compared with controls. NSS 278㎎/㎏ improved gastric emptying more than normal saline or NSS 93mg/kg in normal intact(p=0.026) and antral dilatated rats(p=0.03). NSS enhanced gastric emptying significantly in the NAME treated group(p=0.002). NSS 278mg/kg increased the significant postprandial dominant power than that of NS in normal intact rats, whereas there was no statistical significance in antral dilatated rats. Conclusions : NSS stimulates gastric motility through the cholinergic pathway. We expect that pathologic model with antral dilatation can be used as an exprimental tool which is similar to dyspepsia and NSS would be effective especially in dysmotility-like functional dyspepsia with antral dilatation or impaired reservoir functions such as gastric adaptive relaxation.

• Journal of Technology Innovation
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• v.22 no.2
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• pp.51-75
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• 2014

Sustainability has already become one of the most important innovation policy agendas in many countries. Korea has tried to emulate this global trend in various forms, unfortunately with little success. A very strong tradition of centralized administration in Korea has meant that local communities and municipalities have remained more or less passive in tackling their own sustainability issues and problems. In recent years, with the impetus of huge democratization attempts in Korea since the late 1980s, there have been some local attempts to remedy these imbalances since the early 2000s. A series of local experiments to try and test green alternatives against the very hostile environment have been implemented, with varying degrees of success. This study analyzed cases of transition experiment to sustainable socio-technical system such as MUSIC project, Low Carbon Green Village and Citizens' Sunlight Power Stations. To draw politic meanings for sustainable socio-technical system, these content, process of conversion and feature were examined.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.478-478
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• 2012

Recently, there are many researches in order to increase the deposition rate (D/R) and improve film uniformity and quality in the deposition of microcrystalline silicon thin film. These two factors are the most important issues in the fabrication of the thin film solar cell, and for the purpose of that, several process conditions, including the large area electrode (more than 1.1 X 1.3 (m2)), higher pressure (1 ~ 10 (Torr)), and very high frequency regime (VHF, 40 ~ 100 (MHz)), have been needed. But, in the case of large-area capacitively coupled discharges (CCP) driven at frequencies higher than the usual RF (13.56 (MHz)) frequency, the standing wave and skin effects should be the critical problems for obtaining the good plasma uniformity, and the ion damage on the thin film layer due to the high voltage between the substrate and the bulk plasma might cause the defects which degrade the film quality. In this study, we will propose the new concept of the large-area multi-electrode (a new multi-electrode concept for the large-area plasma source), which consists of a series of electrodes and grounds arranged by turns. The experimental results with this new electrode showed the processing performances of high D/R (1 ~ 2 (nm/sec)), controllable crystallinity (~70% and controllable), and good uniformity (less than 10%) at the conditions of the relatively high frequency of 40 MHz in the large-area electrode of 280 X 540 mm2. And, we also observed the SEM images of the deposited thin film at the conditions of peeling, normal microcrystalline, and powder formation, and discussed the mechanisms of the crystal formation and voids generation in the film in order to try the enhancement of the film quality compared to the cases of normal VHF capacitive discharges. Also, we will discuss the relation between the processing parameters (including gap length between electrode and substrate, operating pressure) and the processing results (D/R and crystallinity) with the process condition map for ${\mu}c$-Si:H formation at a fixed input power and gas flow rate. Finally, we will discuss the potential of the multi-electrode of the 3.5G-class large-area plasma processing (650 X 550 (mm2) to the possibility of the expansion of the new electrode concept to 8G class large-area plasma processing and the additional issues in order to improve the process efficiency.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.239-240
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• 2012

With advancements in semiconductor device technologies, manufacturing processes are getting more complex and it became more difficult to maintain tighter process control. As the number of processing step increased for fabricating complex chip structure, potential fault inducing factors are prevail and their allowable margins are continuously reduced. Therefore, one of the key to success in semiconductor manufacturing is highly accurate and fast fault detection and classification at each stage to reduce any undesired variation and identify the cause of the fault. Sensors in the equipment are used to monitor the state of the process. The idea is that whenever there is a fault in the process, it appears as some variation in the output from any of the sensors monitoring the process. These sensors may refer to information about pressure, RF power or gas flow and etc. in the equipment. By relating the data from these sensors to the process condition, any abnormality in the process can be identified, but it still holds some degree of certainty. Our hypothesis in this research is to capture the features of equipment condition data from healthy process library. We can use the health data as a reference for upcoming processes and this is made possible by mathematically modeling of the acquired data. In this work we demonstrate the use of recurrent neural network (RNN) has been used. RNN is a dynamic neural network that makes the output as a function of previous inputs. In our case we have etch equipment tool set data, consisting of 22 parameters and 9 runs. This data was first synchronized using the Dynamic Time Warping (DTW) algorithm. The synchronized data from the sensors in the form of time series is then provided to RNN which trains and restructures itself according to the input and then predicts a value, one step ahead in time, which depends on the past values of data. Eight runs of process data were used to train the network, while in order to check the performance of the network, one run was used as a test input. Next, a mean squared error based probability generating function was used to assign probability of fault in each parameter by comparing the predicted and actual values of the data. In the future we will make use of the Bayesian Networks to classify the detected faults. Bayesian Networks use directed acyclic graphs that relate different parameters through their conditional dependencies in order to find inference among them. The relationships between parameters from the data will be used to generate the structure of Bayesian Network and then posterior probability of different faults will be calculated using inference algorithms.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.148-148
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• 2011

Recently, there have been many research activities to develop the large-area plasma source, which is able to generate the high-density plasma with relatively good uniformity, for the plasma processing in the thin-film solar cell and display panel industries. The large-area CCP sources have been applied to the PECVD process as well as the etching. Especially, the PECVD processes for the depositions of various films such as a-Si:H, ${\mu}c$-Si:H, Si3N4, and SiO2 take a significant portion of processes. In order to achieve higher deposition rate (DR), good uniformity in large-area reactor, and good film quality (low defect density, high film strength, etc.), the application of VHF (>40 MHz) CCP is indispensible. However, the electromagnetic wave effect in the VHF CCP becomes an issue to resolve for the achievement of good uniformity of plasma and film. Here, we propose a new electrode as part of a method to resolve the standing wave effect in the large-area VHF CCP. The electrode is split up a series of strip-type electrodes and the strip-type electrodes and the ground ones are arranged by turns. The standing wave effect in the longitudinal direction of the strip-type electrode is reduced by using the multi-feeding method of VHF power and the uniformity in the transverse direction of the electrodes is achieved by controlling the gas flow and the gap length between the powered electrodes and the substrate. Also, we provide the process results for the growths of the a-Si:H and the ${\mu}c$-Si:H films. The high DR (2.4 nm/s for a-Si:H film and 1.5 nm/s for the ${\mu}c$-Si:H film), the controllable crystallinity (~70%) for the ${\mu}c$-Si:H film, and the relatively good uniformity (1% for a-Si:H film and 7% for the ${\mu}c$-Si:H film) can be obtained at the high frequency of 40 MHz in the large-area discharge (280 mm${\times}$540 mm). Finally, we will discuss the issues in expanding the multi-electrode to the 8G class large-area plasma processing (2.2 m${\times}$2.4 m) and in improving the process efficiency.

• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.624-631
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• 2014

In this study, a new series of conjugated polymer 3-(5-(5,6-bis(octyloxy)-7-(thiophen-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)-10-(4-(octyloxy)phenyl)-10H-phenothiazine (P1) and 3-(5-(5,6-bis(octyloxy)-7-(thiophen-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)-10-(4-((2-ethylhexyl)oxy)phenyl)-10H-phenothiazine (P2) were synthesised and organic photovoltaics (OPVs) properties were characterized. The push-pull structure polymer consisted of phenothiazine derivative as an electron donor and benzothiadiazole derivative as an electron acceptor. The aliphatic chain substituted aromatic ring was substituted at the position of N in phenothiazine for the electron-rich and improved solubility. Excellent thermal stabilities of P1 and P2 were confirmed by measured Td values as 321.9 and $323.7^{\circ}C$, respectively and the degrees of polymerization were 4,911 (P1) and 5,294 (P2). The maximum absorption wavelength of P1 and P2 were 549 and 566 nm, respectively. The device was fabricated and the OPVs property was measured. As a result, the power efficiency of conversion for P1 and P2 were 0.96 and 0.90%, respectively.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.357-368
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• 2012

The purpose of this study is to empirically examine the impact of enterprise R&D investment on international trade in Korea under the new Normal Era. In order to test whether the time series data of trade variables are stationary or not, we put in operation unit root test and cointegration test. Based on VECM (Vector Error Correction Model), we also apply impulse response functions and variance decomposition to estimate the dynamic effects in the short-run and long-run. The results show that the relationship between enterprise R&D investment and international trade (export and import) exists in the long-run as well as in the short-run. The results of applying impulse response functions and variance decomposition also indicate that the impact of enterprise R&D investment on international trade is positive, and a significant portion of fluctuations in the trade variable is explained by enterprise R&D investment. Therefore, enterprise R&D investment must be continuously increased to improve economic growth with promoting trading competition power in Korea under the new Normal Era.

• Journal of the Korean Geographical Society
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• v.42 no.1 s.118
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• pp.41-62
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• 2007

This paper aims to interpret the changes of the regional inequality between Seoul Metropolitan Area(SMA) and Non-SMA after 1981 on the regulationist approaches that examine institution changes and power dynamics that motivate regional disparities in South Korea. Despite the restrict laws and aims that alms to reduce the concentration into SMA before 1988, the acts were not executed effectively due to the structural selectivity of the bureaucratic authoritarian state of those years. Thus, the regional concentration phenomena of SMA was intensified in the 1980s. However, the democratization in 1987 invoked Non-SMA regions to claim their regional development and it also forced the state to mediate the conflicting interests between the regional agents protesting the SMA concentration and the Capital agents supporting the SMA deregulation. From the early 1990s. the state launched a series of national strategies and policies to diminish regional inequality. They included execution of the existing acts mitigating SMA concentration and construction of industrial complexes in the underdeveloped areas of Non-SMA. Thus, the equalizing polities led the reduction of the concentration of SMA from 1989 to 1997. However, the financial crisis of Korea in 1997 intensified the claims of the Capital agents to deregulate the SMA control. The circumstance also forced the state towards the Capital side that request the deregulation of SMA control. As the result, the regional disparity between SMA and Non-SMA has been enlarged again since 1998.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.165-182
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• 2016

This study examines the competitiveness and cooperativeness among the container ports in East Asia by analyzing their monthly dynamics in eight years (2008-2015). Time series data on container throughput divided into origin and destination (O/D), such as the top six Chinese ports and the transshipment (T/S) ports such as Hong Kong, Busan, and Singapore, are computed with two methods based on the Vector Error Correction Model (VECM). The first Granger causality test results show that Busan T/S has significant bilateral relations with three Chinese O/D ports; and significant unidirectional relations with three other O/D ports. Shenzhen port has significant bilateral relations with Singapore, and has a significant unidirectional relation with Hong Kong port. Co-integrating test results showed that Busan holds negative co-integration with all Chinese O/D ports. Impulse response function (IRF) results show an opposite direction between paired ports. The ratios of the impulse from T/S ports are significantly high to one another in the short-run, but its power declines as time passes. The ratio of the impulse from the Chinese ports to T/S ports is less significant in the short-run period, however, it becomes more significant as time passes. The significance of most shocks was high in the second period, but was diluted after the sixth period.

• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.547-551
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• 1994

A series of samples in the $Nd_{1-x}Ba_xFeO_{3-y}$ system has been prepared by heating the reactants to$1200^{\circ}C$ under an ambient atmosphere, and the solid solutions were identified by X-ray power diffraction analysis. The crystal systems of samples with x = 0.00 and 0.25 were found to be orthorhombic whose local symmetry is similiar to the distorted octahedral with orthoferrite type one, whereas those with x = 0.50 and 0.75 to be the cubic system. Since Fe ions in the solid solutions are a mixed valence state between $Fe^{3+}\;and\;Fe^{4+}$ ions, the nonstoichiometric chemical formulas could be determined from the mole ratio of $Fe^{4+}$ ion and oxygen vacacies. According to the Mossbauer spectroscopic analysis, the presence of 5-coordinated $FeO_5$ was evidenced only in the barium compounds along with $FeO_6,\;and\;FeO_4$, but not in the strontium and calcium compounds. The samples with x = 0.25 and 0.50 show a spectrum of superparamagnetism, which might be due to the formation of a domain of the ferromagnetic interaction between the $Fe^{3+}\;and\;Fe^{4+}$ ions. The electrical conductivities of all samples are within semiconducting range. Since the $Fe^{4+}$ ion acts as an electron acceptor level during the electron transfer between the Fe through intermediate $O^{2-}$ ions, the activation energy of the compounds decreases with the increment of $Fe^{4+}$ content.