• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.31-38
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• 2008

Ad-Hoc network is a network architecture which has no backbone network and is deployed temporarily and rapidly in emergency or war without fixed mobile infrastructures. All communications between network entities are carried in ad-hoc networks over the wireless medium. Due to the radio communications being extremely vulnerable to propagation impairments, connectivity between network nodes is not guaranteed. Therefore, many new algorithms have been studied recently. This study proposes the secondary header approach to the cluster based routing protocol (CBRP). The primary header becomes abnormal status so that the primary header can not participate in the communications between network entities, the secondary header immediately replaces the primary header without selecting process of the new primary header. This improves the routing interruption problem that occurs when a header is moving out from a cluster or in the abnormal status. The performances of proposed algorithm ACBRP(Advanced Cluster Based Routing Protocol) are compared with CBRP. The cost of the primary header reelection of ACBRP is simulated. And results are presented in order to show the effectiveness of the algorithm.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.2
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• pp.15-25
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• 2017

The objective of this study is to investigate the value of rock Korean chessboards as a corroborative evidence that go, the play culture naturalized from the past, was also performed under the pavilion of the mountain stream, and the old tree. This study executes analysis on the location and form of rock Korean chessboards, physical environment such as the position of surrounding space, the origin of the nomination, surrounding landscape, and historical significance through the research analysis of comprehensive present conditions, and highlights the position types, landscape significance, and preservation value of the rock Korean chessboards of Korea from diverse angles. The result is as follows. 1. The styles of Korean chess (將棋), which identically propagated in the representative countries of Eastern culture, Korea, China, and Japan, and modified in accordance with each country's idea and native tendency, were organized, and confirmed the Korean Go as a naturalized native culture. 2. Out of 15 rock Korean chessboards confirmed through this study, 9 (60%) were categorized as rock Korean chessboards, and 6 (40%) were categorized as stone Korean chessboards. Also, the average size of the go boards were $51cm{\times}46.6cm$, which demonstrated not much difference with present day universal go boards. The Pearson correlation coefficient between bed rock and go boards were 0.647, demonstrating a relatively high correlation; the research subject of rock go boards have been constructed in consideration of rationality, convenience, and the value of promotion of public welfare. 3. The results of analysis of location patterns of rock Korean chessboard showed that villages (87%), mooring (73%), plains (60%) and mountains (47%). The most frequent location pattern is mooring and village, and these two factors played the most important role in determining the location of the rock Korean chessboard.

• Journal of Korean Society of Archives and Records Management
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• v.3 no.1
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• pp.159-184
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• 2003

In this research the issues of record management of national archives in Korea are classified into four categories: 1) improving the status of the Central Archives of Korea, 2) constructing a new national archives, 3) revising the law on the record management, 4) creating qualifications for a professional administrator for Archivist. 1) In order to strengthen the function of the Central Archives of Korea, it is very urgent to create a systematic mechanism in which the Central Archives oversees and administers public archives(documents) collected from all the public institutions not only under the Administration but also the legislature and the judicial authorities. 2) This paper suggests that a new National Archives should be a symbolic building representing Korea as archives. Considering the fact that Presidents archives will be a part of this new National Archives, it also suggests that artistic and decorative pieces which embody Korea's representative archives or people should be included in the building. The budget for these should be supplied by the government. 3) This paper looks at the matter of revising the law on Record Management in two respects: (1)strengthening the function of the Central Archives of Korea, (2)making it obligatory to produce archives not open to the public, or making a protection clause for secret archives. This paper proposes that the Central Archives of Korea will be able to collect all the public archives from all the public institutions, and to oversee and administer them by revising the 5th and 6th clauses of the current law on the record management. It also proposes that some laws which make it obligatory to produce archives for documents not open to the public, and which protect those secrecy. 4) Regarding the qualifications for a professional administrator for the record management, this paper suggests lowering the qualification a little to the bachelor's degree of the record management. Also it suggests taking into consideration the persons in charge of the record management in public institutions and acknowledging their qualifications after a certain period of training at the Central Archives of Korea or something like that. In addition, it classifies the ranks of the professional administrators according to their qualifications.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.2
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• pp.39-44
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• 2020

Recently, numerous researches are being conducted in flexible substrate to apply to wearable devices. Particularly, Conductive substrate researches that can implement the wearable devices on clothing are massive. In this study, we formed fiber substrate spraying CNT and Pd mixed solution on it and plated metal layer with electroless plating. Used SEM equipment and EDS analysis to analysis structure of the plated fiber substrate and discovered Ni layer was created. For check electrical properties, mapping was performed to check surface resistance and distribution of resistance of electroless plated fiber substrate with 4-point probe. It was confirmed that conductivity was improved as the duration of electroless plating was increased, and it was found that distribution of resistance by surface location was uniform. Changes in resistance due to mechanical stress were measured through tensile, bending, and twisting tests. As a result, it was confirmed that resistance change of flexible substrate gradually disappeared as plating time increased. Using UTM (Universal testing machine), it was analyzed mechanical properties of the electroless plated substrate with respect to changes in plating time were improved. In the case of conductive fiber substrate in which electroless plating was performed for 2 hours, tensile strength was increased by 16 MPa than fiber substrate. Based on these results, we found that Ni-CNT-Fabric flexible substrate is adequate for clothing-intergrated conductive substrate and we positively expect that this experiment shows flexible substrate can adapt to and develop not only a wearable device technology but also other fields needing flexibility such as battery, catalyst and solar cell.

• Journal of Acupuncture Research
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• v.30 no.4
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• pp.55-68
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• 2013

Objectives : The purpose of this study is to analyze the distribution, relationship, prognosis and improvement score of idiopathic facial palsy inpatients according to constitutional differentiation ; Sasang constition, Hyungsang classification, Sasang constition combined with Hyungsang classification. Methods : A study was done on 102 patients who were diagnosed and treated as idiopathic facial palsy from April 2012 to Nomember 2012 at the Department of Acupuncture and Moxibution Medicine, Dong-eui Oriental University Hospital. Medical records of inpatinets who underwent facial ENoG, NET test were analyzed. Changes of HBGS grade and Yanagihara's score were also evaluated. We classified inpaients acording to Sasang constitution by consulting to Department of Sasang constitutinal medicine, and to Hyungsang classification(Dam-body, Bangkwang-body) by measuring under medical system of 3D facial shapes(RS-400FL). The constitutional differentiation and general characteristics were initially analyzed, and valuse on ENoG, NET were correlated with constitutinal differentiation. Results of HBGS and Yanagihara's score were also correlated with constitutinal differentiation. Results : 1. Each 39.2 percent of idiopathic facial palsy inpatients were the Taeeumin and Soyangin, 21.6 percent were the Soeumin. 2. 75.5 percent of idiopathic facial palsy inpatients were the Bangkwang-body, 24.5 percent were the Dam-body. 3. 34.3 percent of idiopathic facial palsy inpatinets were the Taeeum-Bangkwang, 21.6 percent were the Soyang-Bangkwang, 19.6 percent were the Soeum-Bangkwang, 17.6 percent were the Soyang-Dam, 4.9 percent were the Taeem-Dam, 2 percent were the Soeum-Dam. 4. By sex, the each ratio of Taeeumin, Soeumin, Bangkwang-body, Taeeum-Bangkwang, Soeum-Bangkwang, Soyang-Bangkwang was higher in female, that of Dam-body, Taeeum-Dam, Soyang-Dam was higher in male. 5. By relations between Sasang constitution and Hyungsang classification, the each ratio of Taeeumin and Soeumin was higher in Bangkwang-body. 6. By values on ENoG and NET, evaluations of HBGS's grade and Yanagihara's score, there were no significant difference. Conclusions : In idiopathic facial palsy inpatients, the proportion of Taeeum and Soyang among the Sasang constitution was higher, that of Dam among the Hyungsang classification was higher, that of Taeeum-Bangkwang among the Sasang combined with Hyungsang was the highest. It would seem that Bangkwang-body, female were closely related to Taeeumin, Soeumin. Also, Dam-body were closely related to male. But when comparing groups, there was no statistically significant difference in prognosis and improvement.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.947-953
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• 2005

Previous test results showed that the current ASTM(American Standard for Testing and Materials) grip adapter for GFRP(Glass Fiber Reinforced Polymer) rebar was not fully successful in developing the design tensile strength of GFRP rebars with reasonable accuracy. It is because the current ASTM grip adapter which is composed of a pair of rectangular metal blocks of which inner faces are grooved along the longitudinal direction does not take into account the various geometric characteristics of GFRP rebar such as surface treatment, shape of bar cross section as well as physical characteristics such as poisson effect, elastic modulus in the transverse direction and so on. The objective of this paper is to provide how to proportion the optimum diameter of inner groove in ASTM grip adapter to develop design tensile strength of GFRP rebar. The proportioning of inner groove in ASTM grip adapter is based on the force equilibrium of GFRP rebar between tensile capacity and minimum frictional resistance required along the grip adapter. The frictional resistance of grip adapter is calculated based on the compressive strain compatibility in radial direction induced by the difference between diameter of GFRP rebar and inner groove In ASTM grip. All testing procedures were made according to the CSA S806-02 recommendations. From the preliminary test results on round-type GFRP rebars, it was found that maximum tensile loads acquired under the same testing conditions is highly affected by the diameter of inner groove in ASTM grip adapter. The grip adapter with specific dimension proportioned by proposed method recorded the highest tensile strength among them.

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.239-244
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• 2007

In order to investigate the effect of fluorine ion in the $Li_{1-x}FeO_2Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8) cathode material, it was synthesized $Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8, $0.05{\le}y{\le}0.15$) cathode materials at $350^{\circ}C$ for 10hrs using solid-state method. $Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8, $0.0{\le}y{\le}0.1$ was composed many large needle-like particles of about $1-1.5\;{\mu}m$ and small particles of about 50-100 nm, which were distributed among the larger particles. However, $Li_{1-x}FeO_{1.85}F_{0.15}-Li_xMnO_2$ material showed slightly different particle morphology. The particles of $Li_{1-x}FeO_{1.85}F_{0.15}-Li_xMnO_2$ were suddenly increased and started to be a spherical type of particle shape. $Li/Li_{1-x}FeO_{1.9}F_{0.1}-Li_xMnO_2$ cell showed a high initial discharge capacity of 163 mAh/g and a high cycle retention rate of 95% after 50 cycles. The initial discharge capacity of $Li/Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ ($0.05{\le}y{\le}0.15$) cells increased according to the increase of F content. However, the cycleability of this cell was very rapidly decreased when the substituted fluorine content is over 0.1. We suggested that too large amount of F ion fail to substitute into the $Li_{1-x}FeO_2-Li_xMnO_2$ structure, which resulted in the severe decline of battery performance.

• Journal of the Korean Geosynthetics Society
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• v.13 no.2
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• pp.1-10
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• 2014

In this study, two different types of dredged fill injection methods are introduced and filling experiments were conducted to analyze the impact of each technique to the distribution and deposition of dredged soil fill and how it influence the final tube shape. Two transparent plastic tubes were fabricated to observe the deposition behavior of the deposited fill material. Both tubes measured 4.0 meters in length (L) and has vinyl tube diameters (D) of 0.5m and 0.7m. T-type and I-type inlet system are also introduced in this paper. The influence of this inlet systems to the distribution and deposition behavior of dredged soil fill inside the vinyl tubes were observed during the experiment. After the sedimentation of the slurry mixture, the water on top of the soil sediments are removed and the slurry mixture was re-injected into the vinyl tube, this process was carried out repeatedly. The shape changes of the vinyl tube, e.g. the changes in both tube height and width, are constantly monitored after each slurry injection and water draining phases. Crater formation was observed in the case of I-Type inlet system and a non-uniform sediment distribution occurred. For the diffusion deposit of soil particles to long distance are minimal shape technique using the T-Type inlet system. Therefore the undrain filling height ratio ($H/D_0$) was found to be around 0.54 to 0.64 and the horizontal strain ratio ($W/D_0$) ranges from 1.45 to 1.54. The filling soil height is proportional to dredged-material filling phases, but, horizontal strain ratio is constant or inversely reduced so that the center of tube body is raised in the upward direction.

• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.1-8
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• 2020

Centrifugal pump is a facility that transfers energy to fluid through centrifugal force, which is usually generated by rotating the impeller at high speed, and is a major process facility used in many LNG production bases such as vaporization seawater pump, industrial water and fire extinguishing pump using seawater. to be. Currently, pumps in LNG plant sites are subject to operating conditions that vary depending on the amount of supply desired by the customer for a long period of time. Pumps in particular occupy a large part of the consumption strategy at the plant site, and if the optimum operation condition is not available, it can incur enormous energy loss in long term plant operation. In order to solve this problem, it is necessary to identify the performance deterioration factor through the flow analysis and the result analysis according to the fluctuations of the pump's operating conditions and to determine the optimal operation efficiency. In order to evaluate operation efficiency through experimental techniques, considerable time and cost are incurred, such as on-site operating conditions and manufacturing of experimental equipment. If the performance of the pump is not suitable for the site, and the performance of the pump needs to be reduced, a method of changing the rotation speed or using a special liquid containing high viscosity or solids is used. Especially, in order to prevent disruptions in the operation of LNG production bases, a technology is required to satisfy the required performance conditions by processing the existing impeller of the pump within a short time. Therefore, in this study, the rotation difference of the pump was applied to the ANSYS CFX program by applying the modified 3D modeling shape. In addition, the results obtained from the flow analysis and the curve fitting toolbox of the MATLAB program were analyzed numerically to verify the outer diameter correction theory.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.566-572
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• 2007

Two hybrid catalysts for the direct synthesis of DME were prepared and the catalytic activity of these catalysts were investigated. The hybrid catalyst for the direct synthesis of DME was composed as the catalytic active components of methanol synthesis and dehydration. The methanol synthesis catalyst was formed from the precursor contained Cu and Zn, the methanol dehydration catalyst was used ${\gamma}-Al_2O_3$. As PM-CZ+D and CP-CZA/D, Two hybrid catalysts were prepared by physical mixing method (PM-CZ+D) and precipitation method (CP-CZA/D), respectively. PM-CZ+D was prepared by physically mixing methanol synthesis catalyst and methanol dehydration catalyst, CP-CZA/D was prepared by depositing Cu-Zn or Cu-Zn-Al components on ${\gamma}-Al_2O_3$. The crystallinity and the surface morphology of synthesized catalyst were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) to investigate the physical property of prepared catalyst. And BET surface area by $N_2$ adsorption and the surface area of Cu by $N_2O$ chemisorption were investigated about the hybrid catalysts. In addition, catalytic activity of these hybrid catalysts was examined with varying reaction conditions. At that time, the reaction temperature of $250{\sim}290^{\circ}C$, the reaction pressure of 50~70 atm, the $[H_2]/[CO]$ mole ratio of 0.5~2.0 and the space velocity of $1,500{\sim}6,000h^{-1}$ were investigated the catalytic activity. From these results, it was confirmed that the reactivity of CP-CZA/D was higher than that of PM-CZ+D. When the conditions of reaction temperature, pressure, $[H_2]/[CO]$ ratio and space velocity were $260^{\circ}C$, 50 atm and 1.0, $3,000h^{-1}$ respectively, CO conversion using CP-CZA/D hybrid catalyst was 72% and the CO conversion of CP-CZA/D was more than 20% compared with the CO conversion of PM-CZ+D. It was known that Cu surface area of CP-CZA/D hybrid catalyst was higher than that of hybrid PM-CZ+D catalyst using $N_2O$ chemisorption. It was assumed that the catalytic activity was improved because Cu particle of hybrid catalyst prepared by precipitation method was well dispersed.