• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.129-164
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• 2023

In a situation where the use and introduction of Large Language Models (LLMs) is expanding due to recent developments in generative AI technology, it is difficult to find actual application cases or implementation methods for the use of internal company data in existing studies. Accordingly, this study presents a method of implementing generative AI services using the LLM application architecture using the most widely used LangChain framework. To this end, we reviewed various ways to overcome the problem of lack of information, focusing on the use of LLM, and presented specific solutions. To this end, we analyze methods of fine-tuning or direct use of document information and look in detail at the main steps of information storage and retrieval methods using the retrieval augmented generation (RAG) model to solve these problems. In particular, similar context recommendation and Question-Answering (QA) systems were utilized as a method to store and search information in a vector store using the RAG model. In addition, the specific operation method, major implementation steps and cases, including implementation source and user interface were presented to enhance understanding of generative AI technology. This has meaning and value in enabling LLM to be actively utilized in implementing services within companies.

• Korean Journal of Radiology
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• v.22 no.12
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• pp.1964-1973
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• 2021

Objective: To investigate the diagnostic performance of CT fractional flow reserve (CT-FFR) for myocardial bridging-related ischemia using dynamic CT myocardial perfusion imaging (CT-MPI) as a reference standard. Materials and Methods: Dynamic CT-MPI and coronary CT angiography (CCTA) data obtained from 498 symptomatic patients were retrospectively reviewed. Seventy-five patients (mean age ± standard deviation, 62.7 ± 13.2 years; 48 males) who showed myocardial bridging in the left anterior descending artery without concomitant obstructive stenosis on the imaging were included. The change in CT-FFR across myocardial bridging (ΔCT-FFR, defined as the difference in CT-FFR values between the proximal and distal ends of the myocardial bridging) in different cardiac phases, as well as other anatomical parameters, were measured to evaluate their performance for diagnosing myocardial bridging-related myocardial ischemia using dynamic CT-MPI as the reference standard (myocardial blood flow < 100 mL/100 mL/min or myocardial blood flow ratio ≤ 0.8). Results: ΔCT-FFR_systolic (ΔCT-FFR calculated in the best systolic phase) was higher in patients with vs. without myocardial bridging-related myocardial ischemia (median [interquartile range], 0.12 [0.08-0.17] vs. 0.04 [0.01-0.07], p < 0.001), while CT-FFR_systolic (CT-FFR distal to the myocardial bridging calculated in the best systolic phase) was lower (0.85 [0.81-0.89] vs. 0.91 [0.88-0.96], p = 0.043). In contrast, ΔCT-FFR_diastolic (ΔCT-FFR calculated in the best diastolic phase) and CT-FFR_diastolic (CT-FFR distal to the myocardial bridging calculated in the best diastolic phase) did not differ significantly. Receiver operating characteristic curve analysis showed that ΔCT-FFR_systolic had largest area under the curve (0.822; 95% confidence interval, 0.717-0.901) for identifying myocardial bridging-related ischemia. ΔCT-FFR_systolic had the highest sensitivity (91.7%) and negative predictive value (NPV) (97.8%). ΔCT-FFR_diastolic had the highest specificity (85.7%) for diagnosing myocardial bridging-related ischemia. The positive predictive values of all CT-related parameters were low. Conclusion: ΔCT-FFR_systolic reliably excluded myocardial bridging-related ischemia with high sensitivity and NPV. Myocardial bridging showing positive CT-FFR results requires further evaluation.

• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.306-316
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• 2007

Based on a concept of soundscape, this study aims to investigate Koreans' preference for auditory elements, features, and impressions depending upon the season, and examine how these auditory factors of soundstape and seasons interact with each other and attempt to discover their influence on people's auditory preferences. According to an environmental psychological approach called the caption evaluation method, 45 college students examined the soundscape of Namwon City while racing the streets in four seasons. In order to analyze the interactions between seasons and such auditory factors as elements, features, and impressions, it was conducted the GLM univariate analysis and the NPAR tests for independent samples. The results of the analyses show that there are interactive effects between seasons and auditory factors like elements, features, and impressions and that the auditory factors have an effect on auditory preference. Moreover, as for seasonal preference for auditory elements, it was found that people prefer natural sound in spring, summer, and fall while they prefer social sound in winter. Concerning seasonal preference for auditory features, people place a focus on the behaviors in spring, summer, and winter while they stress the surroundings in autumn, as for seasonal preference for auditory impressions, they make much of sound characteristics in spring and winter but they value the atmosphere of streets in summer and fall. The results of this study can he utilized as useful data in determining which auditory factors among elements, features, and impressions to take into consideration in a soundscape design.

• Journal of IKEEE
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• v.28 no.2
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• pp.221-227
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• 2024

This paper presents a smartphone-attachable vascular compliance monitoring module. The proposed sensor module measures photoplethysmogram (PPG) and reconstructs an accelerated PPG waveform. The feature points are extracted from the accelerated PPG waves, and vascular compliance is estimated using these extracted features. The module is powered via the smartphone's USB terminal and transmits the acquired waveforms along with vascular compliance values through Bluetooth. The transmitted waveforms and vascular compliance value are displayed through the smartphone application. This work proposes an assessment method for consistency of PPG instrumentation, and it was implemented in a processor of sensor module. The proposed sensor module can be easily attached to smartphone that does not support PPG instrumentation, providing simple measurment and numerical analysis of vascular compliance. To verify the performance of the implemented sensor module, we acquired vascular compliance and pulse pressure data from 29 subjects. Pulse pressure, which serves as a representative indicator of vascular compliance, was obtained using a commercial blood pressure monitor. The analysis results showed that the Pearson coefficient between vascular compliance and pulse pressure was 0.778, confirming a relatively high correlation between two metrics.

• Atmosphere
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• v.34 no.3
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• pp.305-317
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• 2024

The study examines the effects of parameters that define the characteristics of raindrops on the simulated precipitation during the summer season over Korea using the Weather Research and Forecasting (WRF) Double-Moment 6-class (WDM6) cloud microphysics scheme. Prescribed parameters, defining the characteristics of hydrometeors in the WDM6 scheme such as a_R, b_R, and f_R in the fall velocity (V_R) - diameter (D_R) relationship and shape parameter (𝜇_R) in the number concentration (N_R) - D_R relationship, presents different values compared to the observed data from Two-Dimensional Video Disdrometer (2DVD) at Boseong standard meteorological observatory during 2018~2019. Three experiments were designed for the heavy rainfall event on August 8, 2022 using WRF version 4.3. These include the control (CNTL) experiment with original parameters in the WDM6 scheme; the MUR experiment, adopting the 50th percentile observation value for 𝜇_R; and the MEDI experiment, which uses the same 𝜇_R as MUR, but also includes fitted values for a_R, b_R, and f_R from the 50th percentile of the observed V_R - D_R relationship. Both sensitivity experiments show improved precipitation simulation compared to the CNTL by reducing the bias and increasing the probability of detection and equitable threat scores. In these experiments, the raindrop mixing ratio increases and its number concentration decreases in the lower atmosphere. The microphysics budget analysis shows that the increase in the rain mixing ratio is due to enhanced source processes such as graupel melting, vapor condensation, and accretion between cloud water and rain. Our study also emphasizes that applying the solely observed 𝜇_R produces more positive impact in the precipitation simulation.

• The KIPS Transactions:PartB
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• v.16B no.4
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• pp.299-308
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• 2009

AAM(Active Appearance Model) is an algorithm to extract face feature points with statistical models of shape and texture information based on PCA(Principal Component Analysis). This method is widely used for face recognition, face modeling and expression recognition. However, the detection performance of AAM algorithm is sensitive to initial value and the AAM method has the problem that detection error is increased when an input image is quite different from training data. Especially, the algorithm shows high accuracy in case of closed lips but the detection error is increased in case of opened lips and deformed lips according to the facial expression of user. To solve these problems, we propose the improved AAM algorithm using lip feature points which is extracted based on a new lip detection algorithm. In this paper, we select a searching region based on the face feature points which are detected by AAM algorithm. And lip corner points are extracted by using Canny edge detection and histogram projection method in the selected searching region. Then, lip region is accurately detected by combining color and edge information of lip in the searching region which is adjusted based on the position of the detected lip corners. Based on that, the accuracy and processing speed of lip detection are improved. Experimental results showed that the RMS(Root Mean Square) error of the proposed method was reduced as much as 4.21 pixels compared to that only using AAM algorithm.

• Parasites, Hosts and Diseases
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• v.30 no.3
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• pp.177-182
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• 1992

Levels of platelets and other hematological values were monitored in 21 Saimiri and 12 Aotus monkeys over a period of three weeks post·infection with monkey·adapted Indochina CDC-1 strain of Plasmedium falciparum. In both Snlinoiri sciureus boliviensis and Aetus nancymai karyotype-1 monkeys the severest thrombocytopenia was observed at 14 days post-infection coinciding with peak parasitemia, neutropenia, Iynlphocytosis, and anemia associated with severe hemoglobinemia and elevated fibrinogen degeneration products(FDP's), MCH and MCV profiles in Aotus monkeys decreased with ascending parasitemia. In contrast, these parameters in Saimiri were characterized by a significant compensatory increase correlating with parasitemia. In general, thrombocytopenia was one of the earliest clinical manifestations of the infection with the platelets returning to normal levels shortly after peak parasitenlia at 14 days. Platelet kinetics had a strong correlation with hematologic and parasitologic values in the Aotus nlodel. No consistent associations were observed between platelet kinetics and other parameters in the Saimiri model. These data indicate that the Aotus model for malaria is more predictable than the Saimiri. Further, platelet turnover rates and recovery provide a useful prognostic parameter during malaria infection. The results are discussed in relation to the value of the two species of monkeys as models for the pathogenesis of human malaria.

• Journal of Distribution Research
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• v.6 no.2
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• pp.19-40
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• 2002

According to the secondary data, private brand(PB)'s share of retail sales is 25-30% in the USA, but about 45 in Korea. In Korea PB's average price is 23.3% less than manufacturer brand. It is very interest that PB's price advantage doesn't have a good effect on it's share of retail sales. This research's objective is to study why Korean consumers don't purchase private brand cheaper than manufacturer brand. A theoretical reasoning depends on information cue theory and means-ends model of perceived value. A unit of analysis is consumers who purchase private brand at E-mart in Pusan city, one of largest discount store in Korea. Hypothesis tested by Lisrel's structural equation model and interesting results as follows: First, favorable brand image among extrinsic cues is most positively correlated with perceived quality/sacrifice and intrinsic cues is also statistically significant. This fact imply that intrinsic cues; package, logo, country of origin are very important in the adoption of private brand in Korea. Second, compared with manufacturer's brand, PB's perceived price is positively correlated with perceived quality/sacrifice. This fact imply a assimilation effect between manufacturer's brand and private brand. Finally, a correlation between perceived sacrifice and PB proneness is satistically insignificant, but perceived quality has a significant effect on its proneness. this fact imply that innovators(about 4% of potential consumer) are risk-taker.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.521-526
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• 2012

More efficient and effective volume management of trade cargo is recently requested due to FTA with foreign country. Above all, the grain is the main cargo needed in Korean food life and was appointed as the core trade cargo during FTA. This study is aimed to forecast future demands of grain volumes which are handled at Incheon port because most of the grain volumes are traded at Incheon port in Korea. System Dynamics (SD) was used for forecasting as the methodology. Also, population, yearly grain consumption per a man, GDP, GRDP, exchange rate, and BDI were used as the factors that influence grain volumes. Simulation duration was from 2000 to 2020 and real data was used from 2000 to 2007. According to the simulation, 2020's grain volumes at Incheon port were forecasted to be about 2 million tons and grain volumes handled at Incheon port were continuously reduced. In order to measure accuracy of the simulation, this study implemented MAPE analysis. And after the implementation, the simulation was decided as a much more accurate model because MAPE value was calculated to be 6.3%. This study respectively examined factors using the sensitivity analysis. As a result, in terms of the effects on grain volume in Incheon Port, the population factor is most significant and exchange rate factor is the least.

• Journal of the Korean Geophysical Society
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• v.1 no.1
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• pp.31-40
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• 1998

Gravimetric and magnetic surveys were conducted in order to reveal near-surface structures such as basements, faults, and fracture zones in an area near Angang, where the Yangsan fault is believed to pass through. Along two lines approximately perpendicular to the strike of the major fault, gravity and magnetic data were measured at 67 stations with a 15 m interval and at 296 stations with a 3 m interval, respectively. Average depth to the magnetic basement is estimated using the spectral analysis method to be 8.5 and 10.0 m along lines located to the east and the west of the Hyeongsan river, respectively. Average value of reduced gravity on the east line is higher than that on the west by the amount of 1.71 mGal, which indicates that the basement rocks are more severely fractured in the western part. Forward gravity modeling along the east line indicates that a fracture zone extends westward from a fault located 210 m west of the eastern end. Density and depth to the bottom of the fracture zone are estimated to be 2.44 g/cm3 and 70 m, respectively. The gravity model study also indicates presence of a small graben, 190 m wide and 3.5 m deep on an average, on the basement surface. The earth surface above the graben is approximately 44 cm lower than the nearby surface. This indicates that the graben might have been formed by recent fault movements.