• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.363-370
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• 2022

In this paper, an estimation algorithm for state of charge (SOC) was applied using an equivalent circuit model (ECM) and an Extended Kalman Filter (EKF) to improve the estimation accuracy of the battery system states. In particular, an observer was designed to estimate SOC along with the aged capacity. In the case of the fresh battery, when SOC was estimated by Kalman Filter (KF), the mean absolute percentage error (MAPE) was 0.27% which was smaller than MAPE of 1.43% when the SOC was calculated by the model without the observer. In the driving mode of the vehicle, the general KF or EKF algorithm cannot be used to estimate both SOC and capacity. Considering that the battery aging does not occur in a short period of time, a strategy of periodically estimating the battery capacity during charging was proposed. In the charging mode, since the current is fixed at some intervals, a strategy for estimating the capacity along with the SOC in this situation was suggested. When the current was fixed, MAPE of SOC estimation was 0.54%, and the MAPE of capacity estimation was 2.24%. Since the current is fixed when charging, it is feasible to estimate the battery capacity and SOC simultaneously using the general EKF. This method can be used to periodically perform battery capacity correction when charging the battery. When driving, the SOC can be estimated using EKF with the corrected capacity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.5
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• pp.500-504
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• 2023

In this study, the heteroepitaxial thin film growth of β-Ga₂O₃ was studied according to the position of the susceptor in mist-CVD. The position of the susceptor and substrate was moved step by step from the center of the hot zone to the inlet of mist in the range of 0~50 mm. It was confirmed that the average thickness increased to 292 nm (D1), 521 nm (D2), and 580 nm (D3) as the position of the susceptor moved away from the center of the hot zone region. The thickness of the lower region of the substrate is increased compared to the upper region. The surface roughness of the lower region of the substrate also increased because the nucleation density increased due to the increase in the lifetime of the mist droplets and the increased mist density. Therefore, thin film growth of β-Ga₂O₃ in mist-CVD is performed by appropriately adjusting the position of the susceptor (or substrate) in consideration of the mist velocity, evaporation amount, and temperature difference with the substrate, thereby determining the crystallinity of the thin film, the thickness distribution, and the thickness of the thin film. Therefore, these results can provide insights for optimizing the mist-CVD process and producing high-quality β-Ga₂O₃ thin films for various optical and electronic applications.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.7
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• pp.325-332
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• 2023

Currently, the world's population has already entered a super-aging era, and the rate is expected to increase rapidly to about 40% by 2050. However, the rapid development of automation technology and the online service sector, the main technologies of the Fourth Industrial Revolution, are still further isolating them in a world where many inconveniences and development technologies are applied. As such, alienation in daily life is widely expanded in various fields, but the financial service sector is one of the must-use areas regardless of age because of its strong nature in the public service sector, and is a very important factor in the period when branches are rapidly decreasing. However, the current utilization rate of mobile banking services is not around 5%, so users over 60 are rarely able to use them. The UX design of the most frequently used remittance service screen in mobile banking services was proposed, and the difficulty of trying to find the preferred bank among 56 or more banks was solved by analyzing the usage rate of each bank and dividing it into three stages by age group from 50 or older. In addition, it was designed to strengthen customized services by showing their recently used banks as the top priority. The design proposed in this study obtained an average of 4.8 points or more out of 5 points as a result of usability satisfaction through interviews with less than 50 senior groups. This study is believed to help each bank upgrade its different mobile banking designs in a unified manner.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.31-31
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• 2021

본 연구는 서부 DMZ 및 접경지역에 속하고 인천광역시 강화군 강화읍에 위치한 퇴모·혈구산(466m) 을 대상으로 수행되었다. 강화군은 우리나라에서 4번째로 넓은 면적의 섬으로 알려져있고, 인천광역시 서북부 경기만의 한강 하구에 위치하고 있으며, 서쪽으로는 석모도 등 부속섬과 서해안, 북쪽으로는 북 한의 황해도 연백시, 동쪽으로는 김포시와 강화대교와 강화초지대교가 육지로 연결되어 있다. 2019년 4 월부터 2020년 10월까지 7회에 걸쳐 계절별로 식물상 조사를 진행하였다. 본 연구에서 확인된 해명산 일대에 분포하는 관속식물의 현황은 92과 257속 353속 4아종 41변종 4품종 총 402분류군으로 확인되었다. 양치식물은 6과 9속 10종 2변종 12분류군, 나자식물은 3과 4속 8종 총 8분류군, 쌍자엽식물은 74과 198속 268종 4아종 30변종 3품종 등 305분류군, 단자엽식물은 9과 46속 67종 9변종 1품종 등 77분류군으로 조사되었다. 또한, 식물구계학적 특정식물 IV급은 등 1분류군, III급은 물박달나무, 병아리꽃나무 등 6분 류군, II급은 갯장구채, 꼬리조팝나무 등 8분류군, I급은 야산고비, 일엽초 등 20분류군으로 파악되었 다. 희귀식물은 산림청 지정 희귀식물 취약종(VU)에 속하는 산들깨와 약관심종(LC)에 속하는 쥐방울덩굴 등 총 2분류군이 확인되었다. 특산식물은 백운산원추리 및 병꽃나무 등 4분류이 파악되었다. 침입외래식물은 애기수영 및 유럽점나무도물 등 39분류군으로 확인되었고, 생태계교란식은 가시박 등 4분류군으로 파악되었다. 주변의 신산저수지 및 고비고개에 큰 공사가 진행되고있어 침입외래식물의 개체수는 크게 증가할 것으로 예측었다. 따라서 장기적인 생태계 보전대책 수립이 필요하다고 판단된다.

• Journal of Life Science
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• v.33 no.12
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• pp.987-994
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• 2023

This study examined the associations between the genotypes of the galactose mutarotase (GALM) gene and carcass traits in the Hanwoo population of Jeju Island, South Korea. The GALM genotypes were determined by the 14-bp (5'-GGTCTAATGACCAG-3') insertion/deletion (InDel) polymorphisms of the 3'-untranslated region (UTR). All three genotypes (LL, LS, and SS) were found in the Hanwoo steer population. The association analysis showed significant associations between genotypes and several carcass traits, including traits related to intramuscular fat content, such as meat quality, marbling score, and backfat thickness (p<0.05). Animals harboring the SS genotype showed not only higher levels of intramuscular fat content but also lower levels of backfat thickness than animals harboring the LL and LS genotypes. On the other hand, no significant associations were found between the GALM genotypes and carcass weight, eye muscle area, meat color, or fat color (p>0.05). Deleting the 14-bp segment in the 3'-UTR resulted in the modification of the secondary structure of RNA and appeared to affect gene expression by interfering with the binding ability of GALM mRNA with RNA-binding proteins and microRNAs. These results suggest that the 14-bp InDel polymorphism in the 3'-UTR region of the GALM gene affects cattle growth traits and carcass quality through galactose metabolism-mediated fat accumulation in muscle and backfat tissues.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.155-163
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• 2009

In text-to-speech systems, the conversion of text into prosodic parameters is necessarily composed of three steps. These are the placement of prosodic boundaries. the determination of segmental durations, and the specification of fundamental frequency contours. Prosodic boundaries. as the most important and basic parameter. affect the estimation of durations and fundamental frequency. Break prediction is an important step in text-to-speech systems as break indices (BIs) have a great influence on how to correctly represent prosodic phrase boundaries, However. an accurate prediction is difficult since BIs are often chosen according to the meaning of a sentence or the reading style of the speaker. In Japanese, the prediction of an accentual phrase boundary (APB) and major phrase boundary (MPB) is particularly difficult. Thus, this paper presents a method to complement the prediction errors of an APB and MPB. First, we define a subtle BI in which it is difficult to decide between an APB and MPB clearly as a variable break (VB), and an explicit BI as a fixed break (FB). The VB is chosen using the classification and regression tree, and multiple prosodic targets in relation to the pith and duration are then generated. Finally. unit-selection is conducted using multiple prosodic targets. In the MOS test result. the original speech scored a 4,99. while proposed method scored a 4.25 and conventional method scored a 4.01. The experimental results show that the proposed method improves the naturalness of synthesized speech.

• The Journal of the Acoustical Society of Korea
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• v.26 no.4
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• pp.159-165
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• 2007

In this paper, we propose a new pre-selection of candidate units that is suitable for the unit selection based Japanese TTS system. General pre-selection method performed by calculating a context-dependent cost within IP (Intonation Phrase). Different from other languages, however. Japanese has an accent represented as the height of a relative pitch, and several words form a single accentual phrase. Also. the prosody in Japanese changes in accentual phrase units. By reflecting such prosodic change in pre-selection. the qualify of synthesized speech can be improved. Furthermore, by calculating a context-dependent cost within accentual phrase, synthesis speed can be improved than calculating within intonation phrase. The proposed method defines AP. analyzes AP in context and performs pre-selection using accentual phrase matching which calculates CCL (connected context length) of the Phoneme's candidates that should be synthesized in each accentual phrase. The baseline system used in the proposed method is VoiceText, which is a synthesizer of Voiceware. Evaluations were made on perceptual error (intonation error, concatenation mismatch error) and synthesis time. Experimental result showed that the proposed method improved the qualify of synthesized speech. as well as shortened the synthesis time.

• Journal of Soil and Groundwater Environment
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• v.14 no.2
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• pp.1-9
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• 2009

This study was objected to identify the effect on water quality and contamination by non-agricultural facilities in 'A' reservoir watershed located in OO city, Kyounggi-do, Korea. Ground- and stream water samples showed (Na+K)-Cl, Ca(Cl, SO$_4$) and Ca-Cl type in an illegally discharging area of sewage and a densely industrial area indicating water contamination. Stream water of an illegally discharging area of sewage had high COD, T-N and T-P. In this area, direct incoming of sewage into stream water was induced ground water system by well pumping, and it made a progress of ground water contaminations with those components. Groundwater of a densely industrial area showed high concentrations of T-N, NO$_3$N. From a nitrogen isotope analysis, stream water of an illegally discharging area of sewage has ${\delta}^{15}N-NO_3$values of 0.7%0 was strongly affected by nitrogen originated from agrochemicals, and a densely industrial area of 19.7%0 from septic system. Ground- and stream water of a livestock fanning area were contaminated with NH$_3$-N and Mn, which was affected by intensive livestock facilities. SAR-conductivity plot indicates the water does not pose either alkalinity or salinity hazard for irrigation. COD, T-N, T-P, NO$3$-N, NH$_3$N and Mn concentrations from contaminated areas were diminished by mixing with 'A' reservoir water. There were no water contaminations in silver towns, vacationlands around reservoir and golf links. Consequently, it should be made a plan of systematic managements for past and- present possible contaminants and sewage systems in preventing water contamination by non-agricultural facilities.

• Journal of Technology Innovation
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• v.23 no.4
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• pp.1-31
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• 2015

Korea has continuously increased investment on R&D to improve global technology competitiveness through technology innovation. Korea's R&D expenditure as a percent of GDP is world's No. 1 as 4.15 and it accomplished 1 trillion won trade volume for 4 consecutive years. However, despite these efforts, technology balance of payment, which is an important factor that can measure nation's technology competitiveness is in a state of chronic deficit and the lowest level among OECD countries. In this paper, we studied methods to improve Korea's technology balance of payment We figured out concept and current state of technology trade and examined the importance of technology trade through making a comparison between commodity trade and technology trade. There have been studies regarding technology trade, but there was no study which tried to figure out cognition on technology trade from the point of view of companies which plays an important role in technology trade. For this, this study distinguished companies with experience in technology trade and which have not and conducted a survey to figure out cognition and current state of companies. The survey result showed noticeable difference on cognition of top decision makers between companies with experience in technology trade and which have not and there are serious shortage in department and staff which is exclusively responsible for technology trade. Also, despite their needs for education regarding technology trade, the ratio of employees who received education is below 10 % of the total respondents. This study suggested improvement methods such as reforming survey methods of technology trade statistics, enhancing social cognition, supporting to vitalize technology export, building infrastructure regarding technology trade, and opening education programs for cultivating experts based on preceding research and industry survey.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.487-496
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• 2017

The marketization in North Korea is spreading rapidly. This study proposes forest rehabilitation strategy for North Korea in light of their major shift toward market economy. This current trend of marketization in North Korea is now affecting the forest sector, especially the way the residents utilize small forest land. For analyzing the influence of marketization on forest management in North Korea, we reviewed the official documents issued by North Korea and related materials of North Korean marketization. The government of Kim Jong Eun has set up policies and systems regarding the spread of marketization, such as guaranteeing individuals a right to dispose certain products on their own and establishing a special economic zone to attract foreign investments. In the forestry sector, the North Korean government has been trying to fully implement its forest restoration plan by carrying out measures like re-claiming of sloping lands that had been previously used by residents. However, as marketization progresses, it is expected that there lies much difficulty in government-led massive mobilization for forest restoration due to the increase of illegal logging to meet high demand for timber, illegal firewood harvesting, collecting non-timber products for livelihoods and illegal crop cultivation to sell in the market. Therefore, South Korea's support for forest restoration should also consider the recent marketization phenomenon in North Korea. It is necessary to formulate strategic measures such as conducting joint commercialization project on agroforestry management using cooperative farming unit, helping to improve income source from small forest lands, and to activate a comprehensive mountain village special economic zone by utilizing forest business. We do hope that our proposed forest rehabilitation strategy in this paper regarding the changes in North Korea's marketization and forest policy can give a meaningful suggestion on supporting forest restoration in North Korea in an effective way.