• The Journal of Korea Robotics Society
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• v.18 no.1
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• pp.72-81
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• 2023

We introduce tightly-coupled GNSS-LiDAR-Inertial state estimator, which is capable of SLAM (Simultaneously Localization and Mapping) and autonomous driving. Long term drift is one of the main sources of estimation error, and some LiDAR SLAM framework utilize loop closure to overcome this error. However, when loop closing event happens, one's current state could change abruptly and pose some safety issues on drivers. Directly utilizing GNSS (Global Navigation Satellite System) positioning information could help alleviating this problem, but accurate information is not always available and inaccurate vertical positioning issues still exist. We thus propose our method which tightly couples raw GNSS measurements into LiDAR-Inertial SLAM framework which can handle satellite positioning information regardless of its uncertainty. Also, with NLOS (Non-light-of-sight) satellite signal handling, we can estimate our states more smoothly and accurately. With several autonomous driving tests on AGV (Autonomous Ground Vehicle), we verified that our method can be applied to real-world problem.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.2
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• pp.131-136
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• 2024

This paper deal with a method for calculating the continuity of Korea Augmentation Satellite System (KASS), which was completed in Korea in December 2023, and a plan to respond in the event that a continuity hazard situation occurs during operation. For this purpose, the International Civil Aviation Organization (ICAO) Satellite Based Augmentation System (SBAS) continuity standards, Wide Area Augmentation System (WAAS), and European Geostationary Navigation Overlay Service (EGNOS) continuity cases are examined in this paper. According to the measures recommended by the ICAO, when the number of continuity risks exceeds a certain level and the level drops drastically, various mitigation operations by country are implemented. Through this, if KASS does not meet ICAO continuity standards in the future, such measures can be referred to. In addition, this paper computes the short-term KASS continuity during the test broadcast period. Although continuity does not meet the ICAO standards, although this test period is too short, further meaningful analysis in the future is required. Additionally, this paper carried out an analysis of the timing and period to systematically calculate the meaningful value of continuity.

• Journal of Koreanology Reviews
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• v.2 no.2
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• pp.1-8
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• 2023

The present study examines the connections and effects of these historical events on South Korea's education system. The research seeks to illuminate private education's complex history and the complex factors that have shaped it by examining these historical trajectories. After the Korean War in the mid-20th century, South Korea went from agrarian to industrial, which shaped private education. Unparalleled economic growth in the 1960s and 1980s altered schooling. South Korea quickly became an industrial powerhouse, and education became crucial for families seeking socioeconomic advancement. The growing middle class, believing education was the key to prosperity, demanded more extra education. South Korean private education's fourth major event occurred during the socioeconomic upheavals of the 1960s-1980s. Prior studies explain how the fast transition from agrarian to industrial society made schooling essential for families seeking upward mobility. Due to the demand for extra education, private tutoring and specialist hagwons flourished. In summary, this study insists that the effects of historical events on South Korean private education demonstrate the interconnection of cultural, economic, and sociological aspects. Educational practitioners must comprehend the historical backdrop, recognize the lasting impact of past events, and use literature-based tools to navigate this complex landscape.

• Korean Circulation Journal
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• v.53 no.5
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• pp.273-293
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• 2023

Pulsed field ablation (PFA) was recently rediscovered as an emerging treatment modality for the ablation of cardiac arrhythmias. Ultra-short high voltage pulses are leading to irreversible electroporation of cardiac cells subsequently resulting in cell death. Current literature of PFA for pulmonary vein isolation (PVI) consistently reported excellent acute and long-term efficacy along with a very low adverse event rate. The undeniable benefit of the novel ablation technique is that cardiac cells are more susceptible to electrical fields whereas surrounding structures such as the pulmonary veins, the phrenic nerve or the esophagus are not, or if at all, minimally affected, which results in a favorable safety profile that is expected to be superior to the current standard of care without compromising efficacy. Nevertheless, the exact mechanisms of electroporation are not yet entirely understood on a cellular basis and pulsed electrical field protocols of different manufactures are not comparable among one another and require their own validation for each indication. Importantly, randomized controlled trials and comparative data to current standard of care modalities, such as radiofrequency- or cryoballoon ablation, are still missing. This review focuses on the "pearls" and "pitfalls" of PFA, a technology that has the potential to become the future leading energy source for PVI and beyond.

• Analyses & Alternatives
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• v.7 no.1
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• pp.115-145
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• 2023

The 20th National Congress of the Chinese Communist Party (hereafter referred to as "the 20th National Congress") was under the global spotlight long before it was held for seven days from 16 to 22 October 2022. People wondered whether Xi Jinping would secure a third term as China's leader or whether he would lay the foundations to be in power forever during the third term. In Korea, the press and media questioned whether the event would become the "crowning of Emperor Xi (Xi Huangdi)," whose power rivaled that of the first emperor in China, Shi Hunagdi, and featured the scene where Hu Jintao was forced to leave the venue during the Congress. On the other hand, many Korean academics focused more on how Xi would organize the Politburo and its Standing Committee and whether the outline of his heirs would appear during the event. This tendency in academia in turn worsened the media's concerns. This paper presents a quantitative analysis of the 20th National Congress Report, as opposed to an analysis of Xi's political intentions at the event. The National Congress Report outlines the Party's visions, goals, and strategies for the next five years in politics, economy, society, culture, foreign affairs, and relationship with Taiwan. The authoritative document is rich in narrative and logic and deserves academic study. This research analyzes the 18th, 19th, and 20th Reports by identifying their keywords and regular expressions and checking their frequency and percentage through text-mining methods. This approach enables the quantification and visualization of the significant changes in the Party's sovereign vision over the fifteen years of Xi's rule from 2013 to 2027.

• The Journal of Industrial Distribution & Business
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• v.11 no.8
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• pp.31-38
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• 2020

Purpose: This study uses 'Autoregressive Integrated Moving Average Model' to predict the impact of a sharp drop in the base rate due to COVID-19 at the present time when government policies for stabilizing house prices are in progress. The purpose of this study is to predict implications for the direction of the government's house policy by predicting changes in house transaction prices and house rental prices after a sharp cut in the base rate. Research design, data, and methodology: The ARIMA intervention model can build a model without additional information with just one time series. Therefore, it is a time-series analysis method frequently used for short-term prediction. After the subprime mortgage, which had shocked since the global financial crisis in April 2007, the bank's interest rate in 2020 is set at a time point close to zero at 0.75%. After that, the model was estimated using the interest rate fluctuations for the Bank of Korea base interest rate, the house transaction price index, and the house rental price index as event variables. Results: In predicting the change in house transaction price due to interest rate intervention, the house transaction price index due to the fall in interest rates was predicted to change after 3 months. As a result, it was 102.47 in April 2020, 102.87 in May 2020, and 103.21 in June 2020. It was expected to rise in the short term. In forecasting the change in house rental price due to interest rate intervention, the house rental price index due to the drop in interest rate was predicted to change after 3 months. As a result, it was 97.76 in April 2020, 97.85 in May 2020, and 97.97 in June 2020. It was expected to rise in the short term. Conclusions: If low interest rates continue to stimulate the contracted economy caused by COVID-19, it seems that there is ample room for house transaction and rental prices to rise amid low growth. Therefore, In order to stabilize the house price due to the low interest rate situation, it is considered that additional measures are needed to suppress speculative demand.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3435-3441
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• 2014

Background: Axillary lymph node status at diagnosis remains the strongest predictor of long-term survival in breast cancer. Patients with more than ten axillary lymph nodes at diagnosis have a poor long-term survival. In this single institutional study, we set out to evaluate the prognosis of this high-risk group in the era of multimodality therapy. Materials and Methods: In this retrospective study, we looked at all breast cancer patients with greater than ten axillary lymph nodes diagnosed at Mount Sinai Medical Center (MSMC) from January 1st 1990 to December 31st 2007 (n=161). In the univariate analysis, descriptive frequencies, median survival, and 5- and 10-year survival rates were estimated for common prognostic factors. A multivariate prognostic analysis for time-to-event data, using the extended Cox regression model was carried out. Results: With a median and mean follow-up of 70 and 89.9 months, respectively, the overall median survival was estimated to be 99 months. The five-year disease-free survival (DFS) was 59.3% and the ten-year DFS was 37.9%, whereas the five- and ten-year overall survival (OS) was 66.6% and 43.9%, respectively. Multivariate analysis revealed a significant improvement in DFS among black patients compared to whites (p=0.05), improved DFS and OS among young patients (ages 21-45) compared to elderly patients (age greater than 70) (p=0.00176, p=0.0034, respectively), and improved DFS and OS among patients whose tumors were ER positive (p=0.049, p=0.0034). Conclusions: In this single institution study of patients with greater than 10 positive axillary nodes, black patients had a significantly improved DFS compared with white patients. Young age and ER tumor positivity was associated with improved outcomes. Using multivariate analysis, there were no other variables associated with statistically significant improvements in DFS or OS including date of diagnosis. Further work is needed to improve breast cancer survival in this subgroup of patients.

• The Korean Journal of Financial Management
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• v.27 no.1
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• pp.121-156
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• 2010

Back-door-listing can be viewed both as M&A and an alternative to IPO. If IPO is an access to the capital market through regulations, back-door-listing would be the way of entering the market through trading. Back-door-listing can be a better choice considering the common wisdom that regulations hinder the functioning of free market system. One would, however, prefer IPO, for the informational asymmetry isless severe in case of IPO. This paper examines if IPO is superior to back-door-listing as to the informational efficiency. The excess buy-and-hold returns of the Kosdaq back-door-listing firms are estimated over the three-year-period since the event. They are compared against the excess buy-and-hold returns of the Kosdaq IPO firms over the same period of time. The results confirm this paper's prediction that IPO should be more information-efficient. Both IPO and back-door-listing firms start with high short-term excess returns and end up with long-term under-performance. However, back-door-listing firms show more significantly damaging long-term results. Furthermore, back-door-listing firms record poorer accounting results over the research period. These results imply that there exists fad at the time of both events and, in case of back-door-listing, this fad is reinforced by the possibility of window dressing.

• Korean Journal of Clinical Pharmacy
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• v.30 no.1
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• pp.19-30
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• 2020

Objective: To describe patterns of spontaneous reporting on adverse events following immunization (AEFIs) using the human papilloma virus (HPV) vaccine according to the Brighton Collaboration (BC) criteria. Methods: We used the Korea Adverse Event Reporting System (KAERS) database including vaccinations between 2008 and 2017. To apply BC criteria, we classified 58 BC AEFIs into World Health Organization Adverse Reaction Terminology (WHO-ART) codes. We applied MedDRA standard medical queries that were pre-defined as five BC AEFIs. Terminology mapping between MedDRA and WHO-ART terms was performed by three researchers. Descriptive statistics of individual case safety reports were analyzed according to BC applicability. Disproportionality analyses were performed on each BC AEFI and each preferred AEFI term according to the case-noncase approach; reporting odds ratio (ROR) and 95% confidence intervals (CI) were calculated. Results: Among the 30,266 reports of vaccinations between 2008 and 2017, 2,845 reports included the HPV vaccine. Of these reports, 1,511 (53.1%) included at least one BC AEFI. Reports from physicians or manufacturers included more BC AEFIs than from other reporters. Injection site reactions and fever were frequently reported in BC AEFIs; spontaneous abortion and ectopic pregnancy (ROR, 14.29 [95% CI, 4.30-47.49]) and vasculitic peripheral neuropathy (ROR, 8.57 [95% CI, 2.61-28.10]) showed the highest ROR. Among non-BC AEFIs, dizziness or myalgia were frequently reported; exposure during pregnancy (ROR, 23.95 [95% CI, 16.27-35.25]) and inappropriate schedule of administration (ROR, 22.89 [95% CI, 16.74-31.31]) showed the highest ROR. Conclusion: BC criteria would be applicable for labeled AEFIs, whereas analyzing non-BC AEFIs would be useful for detecting unlabeled AEFIs.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.507-517
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• 2010

Long-term monitoring was conducted to identify the runoff characteristics of non-point source according to the three forest types (deciduous forest, coniferous forest and mixed forest) in this study. Rainfall events of each deciduous forest, coniferous forest, and mixed forest were 10, 8, 12, respectively. Average runoff depth and coefficients of each forest type were founded to be coniferous forest and were followed by others in turns : deciduous forest, and mixed forest because various conditions (i.e., rainfall property, Antecedent Precipitation Index (API), soil property, slope, and forest management) could change runoff characteristics. In the analysis of the first flush phenomenon, it showed that SS and T-P were sensitive for the first flush phenomenon. The first flush phenomenon of them were showed differently by rainfall intensity, rainfall duration, and amount of rainfall. The research results indicated that range of the Event Mean Concentration (EMC) values in deciduous forest were 0.8~2.4 mg/L for $BOD_5$, 2.0~13.4 mg/L for $COD_{Mn}$, 1.3~2.9 mg/L for DOC, 1.150~3.913 mg/L for T-N, 0.010~0.350 mg/L for T-P and 3.1~291.8 mg/L for SS and in coniferous forest were 0.8~2.2 mg/L for $BOD_5$, 1.9~3.6 mg/L for $COD_{Mn}$, 1.0~2.0 mg/L for DOC, 1.025~2.957 mg/L for T-N, 0.002~0.084 mg/L for T-P and 0.8~5.4 mg/L for SS. Also, range of the EMC values in mixed forest were 1.3~2.3 mg/L for $BOD_5$, 2.4~4.8 mg/L for $COD_{Mn}$, 1.1~2.1 mg/L for DOC, 0.385~2.703 mg/L for T-N, 0.016~0.080 mg/L for T-P and 2.3~30.0 mg/L for SS.