• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1422-1432
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• 2014

Convergent all-electron multi-reference configuration-interaction (MRCI) calculations are performed for a lithium dimer with Kaufmann's Rydberg basis functions. A comparison of the results of these calculations with those of the effective core potential/core polarization potential (ECP/CPP) method and experimental data reveals the deficiency of the all-electron ab initio method. The deficiency is related to the mere 51.9% attainment of electron correlation for the ground state. The percent attainment of electron correlation for the first excited state is slightly better than that for the ground state, preventing us from obtaining better agreements with experimental data by means of increasing the size of basis sets. The Kaufmann basis functions are then used with the ECP/CPP method to obtain the accurate convergent potential energy curves for the $^1\prod_u$ states correlated to Li(2p) + Li(2p) and Li(2s) + Li(n = 2, 3, 4). Quantum defect curves (QDCs) calculated for both the $X^2\sum_g$ and 1 $^2\prod_u$ states of the $Li{_2}^+$ ion and the Lu-Fano plot reveal a strong series-series interaction between the two $2snp{\pi}$ and $2pnp{\pi}$ Rydberg series. The QDCs are then used to resolve assignment problems in the literature. The reassignments, performed by Jedrzejewski-Szemek et al., of the dissociation product of the D $^1\prod$ state from (2s+3d) to (2s+3p) and that of the 6 $^1\prod_u$ from (2s+4d) to (2s+4p) are found to be incorrect. It may be more natural to assign their $2snp{\pi}$ Rydberg series as a $2snd{\pi}$ series. The state, assigned as 5p $^1\prod_u$ by Ross et al. and 4d $^1\prod$ by Jedrzejewski-Szemek et al., is assigned as the 7 $^1\prod_u$ state, correlated to the Li(2s) + Li(4f) limit.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.156-160
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• 2012

Recently, the demands of the large scale machine tools gradually increase to machine the large parts, such as large scale crankshaft, yaw and pitch bearings for the wind power generator and the vehicle or aircraft components. But the high technology is necessary in order to develop the huge machine tools. Furthermore, the global market of it has been monopolized by a few companies. So, we need to develop the large scale machine tools and study its core technology to rush into the increasing market. In this study, we carried out the researches for the important core technology of a multi-tasking, machine tool; a large scale 5-axis machine tool of gantry type for multi-task machining. This study is focused on the design of large size gantry type multi-axis machine. In the case of large size of machine the cross rail deflection in the X-axis is significant. To reduce the deflection due to the eccentric spindle head, a special hollow type design in the cross rail with outside ram is adapted in this study. Also, the Zig-Zag motion in the Y-axis is inevitable with the gantry geometry, which is by the un-balancing, different motion at the left and the right columns moving. We tried to reduce the influence of Zig-Zag motion using FEM with different loading conditions at the left and the right side column.

• Journal of Advanced Navigation Technology
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• v.14 no.2
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• pp.213-219
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• 2010

Recently, a multi-core system is studied for single terminal's operations on various service networks for mobile systems. Therefore, it is expected that mobile systems capable of supporting WCDMA, MC-CDMA, CDMA and WiBro would be developed. Mobile systems for supporting various service networks is able to be implemented on a single chipset via SoC(System one Chip) technology, thus a noble modem design proper for SoC technology is necessary. For high speed data transmission of 4G mobile communication services, OFDM scheme has to be applied. But, an OFDM signal consists of a number of independently modulated subcarriers, and superposition of these subcarriers cause a problem that can give a large PAPR. In this paper, a noble modem design for 4G mobile communication services and PAPR reduction method for solving the PAPR problem are proposed.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.97-97
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• 2010

We demonstrate the hybrid polymer-quantum dot based multi-functional device (Organic bistable devices, Light-emitting diode, and Photovoltaic cell) with a single active-layer structure consisting of CdSe/ZnS semiconductor quantum-dots (QDs) dispersed in a poly N-vinylcarbazole (PVK) and 1,3,5-tirs- (N-phenylbenzimidazol-2-yl) benzene (TPBi) fabricated on indium-tin-oxide (ITO)/glass substrate by using a simple spin coating technique. The multi-functionality of the device as Organic bistable device (OBD), Light Emitting Diode (LED), and Photovoltaic cell can be successfully achieved by adding an electron transport layer (ETL) TPBi to OBD for attaining the functions of LED and Photovoltaic cell in which the lowest unoccupied molecular orbital (LUMO) level of TPBi is positioned at the energy level between the conduction band of CdSe/ZnS and LiF/Al electrode (band-gap engineering). Through transmission electron microscopy (TEM) study, the active layer of the device has a p-i-n structure of a consolidated core-shell structure in which semiconductor QDs are uniformly and isotropically adsorbed on the surface of a p-type polymer core and the n-type small molecular organic materials surround the semiconductor QDs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.7
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• pp.977-985
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• 2021

The LiDAR sensor is attracting attention as a key sensor for autonomous driving vehicle. LiDAR sensor provides measured three-dimensional lengths within range using LASER. However, as much data is provided to the external system, it is difficult to process such data in an external system or processor of the vehicle. To resolve these issues, we develop integrated processing system for LiDAR sensor. The system is configured that client receives data from LiDAR sensor and processes data, server gathers data from clients and transmits integrated data in real-time. The test was carried out to ensure real-time processing of the system by changing the data acquisition, processing method and process driving method of process. As a result of the experiment, when receiving data from four LiDAR sensors, client and server process was operated using background or multi-core processing, the system response time of each client was about 13.2 ms and the server was about 12.6 ms.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.241-252
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• 2024

We analyze the types of Web3 business model innovation (BMI) of the six major Korean game companies by market size. As a result of the analysis, Nexon is watched as the adapter. It introduces blockchain (BC) layer 2, 'Polygon' to the extended ecosystem such as the creator's secondary creation, item utility, and compensation experience using the existing core intellectual property (IP). KakaoGames and Neowiz are watched as the adventurers. KakaoGames introduces BC layer 2, 'Polygon' and 'Near Protocol' to various experiments using tokenomics models in casual games and massively multiplayer online role-playing games (MMORPGs) using several existing popular IPs. Neowiz also introduces BC layer 2, 'Polygon' and 'Avalanche' to the IntellaX platform using existing game IPs. As the reinventor, Netmable positions as a game publisher that releases third-party games based on multi-chain infrastructure such as Klaytn, BNB Chain, Near Protocol, Aptos Foundation, and introduces BC to new core IPs. Finally, there are Wemade and Com2us as the mavericks. They aim to be the Web3 platform operators that create a BC layer 1 ecosystem and provide services that encompass BC games, GameFi, and non-fungible tokens (NFTs). Here are the implications of the four types of BMI. In terms of infrastructure, Nexon, KakaoGames, and Neowiz try to introduce a part of cross-chain, whereas Netmable tries to move toward a complete multi-chain strategy, and Wemade and Com2us also try to consider multi-chain, even if they have the full BC introduction. In terms of defending against market decline, Nexon and Netmable have a different position. Nexon which has a greater market dominance, only tries to continuously experiment, but Netmable is aggressively focusing on monetizing new products. Attacks on growth aspirations also show two different positions. KakaoGames and Neowiz only try to aggressively explore, while WeMade and Com2us try to set new standards for industrial innovation.

• Journal of Korean Society on Water Environment
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• v.40 no.5
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• pp.243-257
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• 2024

Although lakes are an important part of freshwater, research on biological methods for assessing ecological integrity of Korean lakes is insufficient. Therefore, this study aimed to develop Lakes Benthic Macroinvertebrates Multi-Metric Index (LBMMI) to assess the ecological integrity of lakes in Korea to further understand Korean lake's ecosystem. We used biological data from 388 sampling units of national lake monitoring programs from 2022 to 2023 and water quality data from Water Environment Information System (WEIS). As a result, firstly, reference points and disturbed points were selected through Principal Component Analysis (PCA). Secondly, six core metric elements (Pielou's Evenness index (J), Total number of taxa (To.t), Percent of taxa in insecta (% I.t), Percent of individuals in Oligochaeta and chironomidae(tuble) (% OliCht.i), Percent of taxa in Predator (% Pe.t), and Percent of taxa in Clingers (% CL.t) were selected through discriminant analysis and relationship-test. Lastly, LBMMI was calculated for each sampling point by scoring using core metric elements and five grades were assigned for LBMMI scores using a Beta probability distribution model, with the suitability of LBMMI reviewed by comparing it with TSI_KO. LBMMI developed in this study is expected to appropriately assess ecological integrity of Korean lakes and provide a basis for further research on lake environment conservation.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.84-97
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• 2017

Water vapor and thermal transmission properties of high emotional garments are important to evaluate wear comfort; in addition, the measuring methods of these properties are also critical for breathable and warm suit fabrics. In this study, the water vapor and thermal properties of composite yarn fabrics made of CoolMax, Tencel, and Bamboo fibers with filaments were measured and compared according to the measuring method. Water Vapor Transmittance (WVT) of the fabric woven by the sheath/core composite yarn in the warp direction was the highest due to the small staple fiber volume in the sheath/core yarn structure and high air voids in the sheath/core yarn fabrics. This property was also the highest in fabrics woven by bamboo staple yarns in the weft direction, and was the lowest on hi-multi filament fabrics. However, water vapor resistance ($R_{ef}$) of these fabrics by KSK ISO 11092 showed the opposite results to the water vapor transmittance method ($CaCl_2$ method); in addition, its correlation coefficient was low. The correlation coefficient between $R_{ef}$ and the drying rate was 0.719; therefore, the measurement mechanism of $R_{ef}$ is analogous to the drying property measurement. The thermal conductivity of the fabrics woven with compact staple yarn showed a high value; however, the hi-multi filament fabric showed low thermal conductivity. Therefore, fiber characteristics affect thermal properties more than yarn structure. The correlation between thermal property and moisture transport was also low. This study showed that: water vapor transmittance was active at the loose yarn structure, dry heat transport was vigorous at the compact yarn structure, and heat transport was affected more by fiber characteristics than yarn structure. In conclusion, sheath/core composite yarns were relevant to the high absorptive cool suit along with siro-fil and CoolMax/Bamboo staple yarns that were relevant to the heat diffusive cool suit.

• Anxiety and mood
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• v.13 no.2
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• pp.66-73
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• 2017

Objective : The purpose of this study was to examine the effects of adjunctive aripiprazole versus bupropion on specific symptoms of depression. Methods : Data were from 6-week, randomized, prospective, open-label multi-center study in 103 patients with major depressive disorders. Participants were randomized to receive aripiprazole (2.5-10 mg/day) or bupropion (150-300 mg/day) for 6 weeks. Change in four subscales of the 17-item Hamilton Depression Rating Scale (HAM-D17) that capture core depression symptoms was determined, and change in individual HAM-D17 items was also assessed. Changes in three composite subscales-anxiety, insomnia, and drive were also examined. Results : Within-group change in the four core subscales was large [effect size (ES)=1.30-1.47] and it was similar to that in the HAM-D17 total score. Differences between aripiprazole and bupropion were significant for each of the four core subscales and the HAM-D17 total score favored aripiprazole (p<0.001). On three composite scales, both treatments caused substantial changes in anxiety (within-group ES=1.10 (aripiprazole) vs. 1.00 (bupropion)], insomnia (ES=0.75 vs 0.50), and drive (ES=1.17 vs 1.15). Conclusion : This results suggested that both aripiprazole and bupropion adjunctive therapies with selective serotonin reuptake inhibitors resulted in significant and clinically meaningful changes in core symptom subscales for depression.

• Journal of Science Education
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• v.43 no.1
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• pp.94-118
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• 2019

The purpose of this study is to explore the multi-faceted understanding and issues of science subject matter competencies from the trends of competency-based curriculum discourse, and to examine the relationship between general core competencies and science subject matter competencies. First, we examined the theoretical background of competency-based curriculum focusing on behaviorism, humanism, and its comprehensive synthesis. After that, we reviewed OECD's competency-related projects (DeSeCo; OECD Education 2030), US Next-Generation Science Standards (NGSS) and Korea's 2015 Revised National Curriculum from the viewpoint of competency-based curriculum. After that, we summarized and systematically analyzed a list of competencies, 105 general core competencies and 45 science subject matter competencies proposed by 15 important documents from home and abroad. The results of this study are as follows: First, the issues of the proper number, appropriate dimension, and how individual competencies should be unique and independent were pointed, in terms of defining and categorizing competencies. Second, it was suggested that the competency items are presented in various dimensions such as personal-micro dimension, community meso-dimension, and social-macro dimension. Meso-dimension was placed on both general core competencies and subject matter competencies. Third, in the relationship between general core competencies and subject matter competencies, the former emphasizes macro-dimension, and the latter emphasizes micro-dimension, revealing an existing gap, and where the two can meet each other is the meso-dimension. These discussions are thought to provide insight into the understanding of competencies in the national curriculum, including the 2015 Revised National Curriculum.