• Title/Summary/Keyword: least squares

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Senior' Use of Text Messages and SNS and Contact with Informal Social Network Members (노인의 문자메시지 및 SNS 활용역량과 비공식적 사회관계망과의 접촉에 관한 연구)

  • Jung, Chanwoo;Choi, Heejeong
    • Journal of Digital Convergence
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    • v.19 no.3
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    • pp.401-414
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    • 2021
  • The purpose of this study was to examine the associations of Korean older adults' use of Social Network Service (SNS) and text messages with frequency of contact with 1) non-coresident adult children, 2) siblings and relatives, or 3) friends, neighbors, and acquaintances. Data were drawn from the 2017 Survey of Living Conditions and Welfare Needs of Korean Older Persons 65+ (N=8,392), and older adults were categorized into 4 groups depending on their familiarity with use of SNS and text messages. Ordinary Least Squares regression models were estimated for analyses. Results revealed that older users of both types of communication media reported frequent exchanges of calls, text messages, etc. with both family and friends. However, using SNS and text messages was consistently related to more face-to-face contact with non-family members. To conclude, older adults' familiarity with communication media could be key to exchanges of emotional and instrumental support with informal social network members and quality of life in the community. Overall, our results highlight the importance of information communication education targeting older adults for continued involvement with their informal social network members.

Development of Code-PPP Based on Multi-GNSS Using Compact SSR of QZSS-CLAS (QZSS-CLAS의 Compact SSR을 이용한 다중 위성항법 기반의 Code-PPP 개발)

  • Lee, Hae Chang;Park, Kwan Dong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.6
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    • pp.521-531
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    • 2020
  • QZSS (Quasi-Zenith Satellite System) provides the CLAS (Centimeter Level Augmentation Service) through the satellite's L6 band. CLAS provides correction messages called C-SSR (Compact - State Space Representation) for GPS (Global Positioning System), Galileo and QZSS. In this study, CLAS messages were received by using the AsteRx4 of Septentrio which is a GPS receiver capable of receiving L6 bands, and the messages were decoded to acquire C-SSR. In addition, Multi-GNSS (Global Navigation Satellite System) Code-PPP (Precise Point Positioning) was developed to compensate for GNSS errors by using C-SSR to pseudo-range measurements of GPS, Galileo and QZSS. And non-linear least squares estimation was used to estimate the three-dimensional position of the receiver and the receiver time errors of the GNSS constellations. To evaluate the accuracy of the algorithms developed, static positioning was performed on TSK2 (Tsukuba), one of the IGS (International GNSS Service) sites, and kinematic positioning was performed while driving around the Ina River in Kawanishi. As a result, for the static positioning, the mean RMSE (Root Mean Square Error) for all data sets was 0.35 m in the horizontal direction ad 0.57 m in the vertical direction. And for the kinematic positioning, the accuracy was approximately 0.82 m in horizontal direction and 3.56 m in vertical direction compared o the RTK-FIX values of VRS.

Predicting Calcium and Phosphorus Concentrations in Imported Hay by near Infrared Reflectance Spectroscopy (근적외선분광법을 이용한 수입건초의 Ca과 P 함량 예측)

  • Lee, Bae Hun;Kim, Ji Hye;Oh, Mirae;Lee, Ki Won;Park, Hyung Soo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.1
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    • pp.29-34
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    • 2021
  • Near infrared reflectance spectroscopy (NIRS) is routinely used for the determination of nutrient components of forages. However, little is known about the impact of sample preparation and wavelength on the accuracy of the calibration to predict minerals. This study was conducted to assess the effect of sample preparation and wavelength of near infrared spectrum for the improvement of calibration and prediction accuracy of Calcium (Ca) and Phosphorus (P) in imported hay using NIRS. The samples were scanned in reflectance in a monochromator instrument (680-2,500 nm). Calibration models (n = 126) were developed using partial least squares regression (PLS) based on cross-validation. The optimum calibrations were selected based on the highest coefficients of determination in cross validation (R2) and the lowest standard error of cross-validation (SECV). The highest R2 and the lowest SECV were obtained using oven-dry grinded sample preparation and 1,100-2,500 nm wavelength. The calibration (R2) and SECV were 0.99 (SECV: 468.6) for Ca and 0.91 (SECV: 224.7) for P in mg/kg DM on a dry weight, respectively. Results of this experiment showed the possibility of NIRS method to predict mineral (Ca and P) concentration of imported hay in Korea for routine analysis method to evaluate the feed value.

Direct Switch from Tiotropium to Indacaterol/Glycopyrronium in Chronic Obstructive Pulmonary Disease Patients in Korea

  • Lee, Sang Haak;Rhee, Chin Kook;Yoo, Kwangha;Park, Jeong Woong;Yong, Suk Joong;Kim, Jusang;Lee, Taehoon;Lim, Seong Yong;Lee, Ji-Hyun;Park, Hye Yun;Moon, Minyoung;Jung, Ki-Suck
    • Tuberculosis and Respiratory Diseases
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    • v.84 no.2
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    • pp.96-104
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    • 2021
  • Background: Many chronic obstructive pulmonary disease (COPD) patients receiving monotherapy continue to experience symptoms, exacerbations and poor quality of life. This study aimed to assess the efficacy and safety of direct switch from once-daily tiotropium (TIO) 18 ㎍ to indacaterol/glycopyrronium (IND/GLY) 110/50 ㎍ once daily in COPD patients in Korea. Methods: This was a randomized, open-label, parallel group, 12-week trial in mild-to-moderate COPD patients who received TIO 18 ㎍ once daily for ≥12 weeks prior to study initiation. Patients aged ≥40 years, with predicted post-bronchodilator forced expiratory volume in 1 second (FEV1) ≥50%, post-bronchodilator FEV1/forced vital capacity <0.7 and smoking history of ≥10 pack-years were included. Eligible patients were randomized in a 1:1 ratio to either IND/GLY or TIO. The primary objective was to demonstrate superiority of IND/GLY over TIO in pre-dose trough FEV1 at week 12. Secondary endpoints included transition dyspnea index (TDI) focal score, COPD assessment test (CAT) total score, and rescue medication use following the 12-week treatment, and safety assessment. Results: Of the 442 patients screened, 379 were randomized and 347 completed the study. IND/GLY demonstrated superiority in pre-dose trough FEV1 versus TIO at week 12 (least squares mean treatment difference [Δ], 50 mL; p=0.013). Also, numerical improvements were observed with IND/GLY in the TDI focal score (Δ, 0.31), CAT total score (Δ, -0.81), and rescue medication use (Δ, -0.09 puffs/day). Both treatments were well tolerated by patients. Conclusion: A direct switch from TIO to IND/GLY provided improvements in lung function and other patient-reported outcomes with an acceptable safety profile in patients with mild-to-moderate airflow limitation.

Establishment of a Nondestructive Analysis Method for Lignan Content in Sesame using Near Infrared Reflectance Spectroscopy (근적외선분광(NIRS)을 이용한 참깨의 lignan 함량 비파괴 분석 방법 확립)

  • Lee, Jeongeun;Kim, Sung-Up;Lee, Myoung-Hee;Kim, Jung-In;Oh, Eun-Young;Kim, Sang-Woo;Kim, MinYoung;Park, Jae-Eun;Cho, Kwang-Soo;Oh, Ki-Won
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.67 no.1
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    • pp.61-66
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    • 2022
  • Sesamin and sesamolin are major lignan components with a wide range of potential biological activities of sesame seeds. Near infrared reflectance spectroscopy (NIRS) is a rapid and non-destructive analysis method widely used for the quantitative determination of major components in many agricultural products. This study was conducted to develop a screening method to determine the lignan contents for sesame breeding. Sesamin and sesamolin contents of 482 sesame samples ranged from 0.03-14.40 mg/g and 0.10-3.79 mg/g with an average of 4.93 mg/g and 1.74 mg/g, respectively. Each sample was scanned using NIRS and calculated for the calibration and validation equations. The optimal performance calibration model was obtained from the original spectra using partial least squares (PLS). The coefficient of determination in calibration (R2) and standard error of calibration (SEC) were 0.963 and 0.861 for sesamin and 0.875 and 0.292 for sesamolin, respectively. Cross-validation results of the NIRS equation showed an R2 of 0.889 in the prediction for sesamin and 0.781 for sesamolin and a standard error of cross-validation (SECV) of 1.163 for sesamin and 0.417 for sesamolin. The results showed that the NIRS equation for sesamin and sesamolin could be effective in selecting high lignan sesame lines in early generations of sesame breeding.

The Effect of Virtual Human Lecturer's Human Likeness on Educational Content Satisfaction: Focused on the Theory of Experiential Economy (가상 휴먼 강사의 인간 유사도가 교육 콘텐츠 만족감에 미치는 영향: 체험경제이론을 중심으로)

  • Gong, Li;Bae, Sujin;Kwon, Ohbyung
    • The Journal of the Korea Contents Association
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    • v.22 no.7
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    • pp.524-539
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    • 2022
  • With the advent of generative artificial intelligence technology, it became possible to create a virtual human, and produce a lecture video only with textual information. It is expected that the virtual human will enhance the efficient production of educational contents and the student's entertainment experience and satisfaction. However, there have been still few studies that have demonstrated the process of how virtual human technology reaches students' satisfaction. Therefore, the purpose of this study is to empirically examine whether the human likeness, which is the main characteristic of a virtual human based on Uncanny Valley theory, affects human experience and satisfaction. In particular, human likeness of the Uncanny Valley theory was subdivided into human likeness in the visual and verbal dimensions, and the process of reaching satisfaction was understood based on the experience economy model. In particular, human similarity in Uncanny Valley theory was classified as similarity in the visual and language levels, and the process of reaching satisfaction based on the experiential economic model was analyzed with a partial least squares structure model equation (PLS-SEM). The survey was conducted online for a panel of office workers at a specialized research institution in China. The results indicate that both the visual and verbal human likeness had a positive effect on experience economy factors (education, entertainment, esthetic, escape), and then these experiential factors had a significant effect on satisfaction. The results also provide some suggestions to consider when designing educational contents by virtual human.

Effect of Animal-Welfare Environment on the Metabolomic Properties of Breast and Thigh Meat from Two Broiler Strains (동물복지 사육환경이 두 육계 품종의 가슴육 및 다리육의 대사체학적 특성에 미치는 효과)

  • Lee, Dongheon;Jung, Jong Hyun;Jo, Cheorun
    • Korean Journal of Poultry Science
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    • v.48 no.4
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    • pp.239-253
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    • 2021
  • This study investigates the metabolomic changes in breast and thigh meat from Cobb and Ross 308 chickens regarding the rearing environment. One-day-old Cobb and Ross broilers were raised for 35 days in conventional and animal welfare farms with, amongst others, different floor sizes, stock densities, and ammonia concentrations. One-dimensional 1H nuclear magnetic resonance, orthogonal partial least squares-discriminant analysis (OPLS-DA), and pathway analyses were performed to analyze the metabolomic properties of broiler meat. For breast meat, only those from the Ross strain could be separated according to the environment in the OPLS-DA plot. Ross breast meat from animal welfare farms showed significantly higher acetate, anserine, creatine, and inosine monophosphate content than those from conventional farms (P<0.05). In contrast, for thigh meat, the Cobb strain was differentiated using OPLS-DA. The contents of five metabolites, such as glucose and lactate, were higher in thigh meat from animal welfare farms; however, nine metabolites, including seven free amino acids, were lower compared to those from conventional farms (P<0.05). Pathway analysis was performed to interpret the biological changes in chicken meat based on environmental factors. The results indicated that the animal welfare environment led to significant changes in four metabolic pathways in Ross breast meat and in 20 metabolic pathways in Cobb thigh meat (P<0.05). In conclusion, the animal welfare environment could influence the metabolomic properties of Ross breast meat and Cobb thigh meat, which may affect the sensory quality of meat.

Analyzing the impact on logistics outsourcing success for Ugandan food processing firms through third-party logistics service providers' capabilities (제3자 물류 서비스공급자의 역량을 통한 우간다 식품 가공업체의 물류 아웃소싱 성공에 대한 영향 분석)

  • Alioni, Christopher;Park, Byungin
    • Journal of Korea Port Economic Association
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    • v.38 no.4
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    • pp.45-64
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    • 2022
  • Due to the recent and rapid globalization, logistics outsourcing has expanded globally and is seen as a means of creating a robust logistics system. However, many businesses continue to have difficulties with their logistics outsourcing contracts, which compels them to reinstate the logistics function for internal management. This study aims to investigate how organizational capabilities of logistics service providers (LSPs), notably flexibility, integration, innovation, and technological capabilities, impact on the logistics outsourcing success in Ugandan food processing firms. Using a structured questionnaire survey, cross-sectional data collected from 211 food processing firms in Kampala - Uganda were analyzed by partial least squares-structural equation modeling (PLS-SEM) using SmartPLS 3.3.7 software to examine the theorized relationships. The study findings revealed that whereas the technological and innovation capabilities positively and significantly influence logistics outsourcing success, the effects of flexibility and integration capabilities were insignificant. Additionally, the importance-performance map analysis (IPMA) reveals that the technological capability is a priority capability, followed by the innovation capability if logistics outsourcing success is to be achieved. Conversely, flexibility and integration capabilities are of low priority.

Empirical Study About ODA Effects on Job Creation

  • Seung Hee Ha;JaeHong Park
    • Journal of Korea Trade
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    • v.26 no.6
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    • pp.1-19
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    • 2022
  • Purpose - This study empirically investigates the effects of Official Development Assistance (ODA) on the economic activities of private actors in recipient countries. As a proxy for the economic activities of private actors, we utilize the job creation activities of foreign subsidiaries in recipient countries. The foreign subsidiaries provide a foundation for economic development by creating paying jobs. That is, if ODA has been successfully transferred to foreign subsidiaries, then these foreign subsidiaries should help economic growth and help create a boom in the local market by providing jobs. These jobs eventually lead to the achievement of the primary aims of foreign aid, including poverty reduction. Thus, this study empirically examines the relationship between ODA and the number of jobs created by foreign subsidiaries in recipient countries. Design/methodology - This is the first study to examine the effects of the ODA on the job creation of foreign subsidiaries because it has been hard to obtain internal information related to the employment status of foreign subsidiaries. Fortunately, we have a unique panel dataset provided by the Export-Import Bank of Korea (KEXIM) for 2006 to 2013. In terms of the empirical specification, we use the generalized least squares (GLS) method. The panel GLS estimator allows us to have an efficient estimation that overcomes the limitations of the panel data. It employs assumptions about the heteroscedasticity between the panels and makes an autocorrelation of the error term within each panel. Findings - We find that ODA influences job creation in foreign subsidiaries. In particular, we found that ODA creates more jobs in sales than in managerial or production positions. This study also shows that the effect of the ODA on the foreign subsidiaries' job creation activities depend on the purpose of the ODA. By examining ODA effects on the foreign subsidiaries' economic activities (e.g., job creation), this study fills a gap in the current literature. Originality/value - Existing studies that focus on the ODA effect have either a macroeconomic point or a microeconomic point of view. However, both approaches do not explain how well foreign aid has influenced private economic actors of recipient countries. In essence, previous researchers found it difficult to obtain the necessary data for internal employment status from foreign subsidiaries. However, thanks to the Korea Export-Import Bank, this study shows that ODA indeed influences the job creation activities of foreign subsidiaries even after controlling for other factors such as FDI, GDP growth rate, employment rate, household expenditure, mother firms' share, etc. By doing so, we can examine how ODA influences the job creation of foreign subsidiaries, which might help economic development and reduce the amount of poverty in recipient countries.

SNU 1.5MV Van de Graaff Accelerator (IV) -Fabrication and Aberration Analysis of Magnetic Quadrupole Lens- (SNU 1.5MV 반데그라프 가속기 (IV) -자기 4극 렌즈의 제작과 수차의 분석-)

  • Bak, H.I.;Choi, B.H.;Choi, H.D.
    • Nuclear Engineering and Technology
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    • v.18 no.1
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    • pp.1-8
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    • 1986
  • A magnetic quadrupole doublet was fabricated for use at the pre-target position of SNU 1.5MV Van de Graaff accelerator and then its optical characteristics were measured and analysed. The physical dimensions are: pole length 180mm, aperture radius 25mm, pole tip radius 28.75mm. Material for poles and return yokes is carbon steel KS-SM40C. Coils have 480 turns per one pole and air-cooling is adopted. Applying the d.c. current 2.99$\pm$0.03A to the lens, and using the Hall probe, magnetic field elements $B_{\theta}$ , $B_{\gamma}$, were measured at the selected Points along each coordinate direction r,$\theta$, z. From the area integration and orthogonal polynomial fitting for the measured data, the magnetic Field gradient G=566.3$\pm$2.1 gauss/cm at lens center, the effective length L=208.3$\pm$1.44mm along the lens axis have been obtained. The harmonic contents were determined up to 20-pole from the generalized least squares fitting. The results indicate that sextupole/quadrupole is below 1.4$\pm$0.9% and all the other multipoles are below 0.5% in the region within 18mm radius at the center of lens.

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