• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.31-37
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• 2021

Recently, in the market of home appliances, the technical differentiation of products using convergence technology has been receiving a lot of response to satisfy consumer demand. However, air-conditioner products are an area that requires research and development in the early stages of convergence technology. In this paper, it is developed that a non-contact bio-signal(respiration, movement) collection technology using IR-UWB(Impulse-Radio Ultra Wideband) technology, which controls the air-conditioner direction according to the user's location and also monitors sleep to provide an optimal sleep environment. In addition, emotional lighting and ASMR are developed to provide a comfortable and emotional place of life. Finally, based on the developed convergence technology, we develop intelligent smart air-conditioning services for the convenience of daily life and a comfortable resting space.

• Journal of Clinical Nutrition
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• v.10 no.2
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• pp.38-44
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• 2018

Purpose: Parenteral nutrition (PN) is known to provide therapeutic beneficial improvements in malnourished patients for whom enteral nutrition is not feasible. The objective of this study was to investigate the current clinical characteristics and utilization of PN in Korea. Methods: We analyzed the Health Insurance Review Agency National Inpatients Sample database from 2014 to 2016, which included 13% of all hospitalized patients in Korea. Adult patients aged 20 years or older and receiving premixed multi-chamber bag containing PN were included for this study. Patient characteristics, admission type, primary diagnosis, and hospital demographics were evaluated. SAS version 9.4 was used for data analysis. Results: From 2014 to 2016, 149,504 patients received premixed PN, with 226,281 PN prescriptions being written. The mean patient age was 65.0 years, and 81,876 patients (54.8%) were male. Premixed 3-chamber bag and 2-chamber bag PN solutions were utilized in 131,808 (88.2%) and 32,033 (21.4%) patients, respectively. The number of patients hospitalized through the emergency department were 70,693 (47.3%), whereas 43,125 patients (28.8%) were administered PN in intensive care units. In the adult PN patients, the highest primary diagnosis was malignant neoplasm of the stomach (8,911, 6.0%), followed by organism unspecified pneumonia (7,008, 4.7%), and gastroenteritis and colitis of unspecified origin (6,381, 4.3%). Overall, 34% of adult PN patients were diagnosed with malignancies, the most common being neoplasm of the stomach (17.7%), neoplasm of bronchus/lung (11.2%), neoplasm of colon (11.1%), and neoplasm of liver/intrahepatic bile ducts (10.0%). PN solutions were most frequently administered in the metropolitan area (55.0%) and in hospitals with more than 1,000 beds (23.6%). Conclusion: PN was commonly administered in older patients, with primary diagnosis of malignancy in a significant number of cases. This study is the first large-scale description of PN-prescribing patterns in real-world clinical practice in South Korea.

• Health Policy and Management
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• v.28 no.4
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• pp.352-359
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• 2018

Background: The purpose of this study is to propose an analysis of trends and characteristics of high-cost patients who take over 40% of total national health insurance medical expenses. Methods: It has been analyzed the tendency of high-cost patients by open data based on the medical history information of 1 million people among national health insurance subscriber from 2002 to 2015. To conduct detailed study of characteristics of high-cost patients, multiple regression has been performed by sex, age, residence, main provider, and admission status based on the top 5% group. Results: The amount of medical expenses and the number of high-cost patients have gradually increased in decades. The number of high-cost patients for Korean won (KRW) 5,000,000 category has increased by 7.6 times, KRW 10,000,000 category has increased by 14.1 times in comparing of year 2002 and 2015. Top 5% medical expenses have increased by 4.6 times. In consideration of the characteristics of patients, the incidence of high medical expenses has been higher in female patients than male ones, the older patients than in the younger. Patients residence in Gyeonsang or Jeonla province have had a high incidence of medical expenses than other area. The disease including dementia, cerebral infarction, and cerebrovascular disease for high-cost patients has been also increased. Conclusion: The major increase factor for high medical expenses is the aging of population. The elderly population receiving inpatient care residing in the province that increases high medical costs have to management. There is an urgent need to develop a mechanism for predicting and managing the cost of high-cost medical expenses for patients who have a heavy financial burden.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.897-906
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• 2022

In this paper, we propose a novel MAC protocol based on the harmonic transmission of ACK, called HAT-LoRa, for improving the reliability and the utilization in multiple gateway LoRa Networks. LoRa is basically vulnerable to collision due to the primitive pure ALOHA-like MAC. Whereas data frame delivery can be guaranteed by the transparent bridge of multiple receiving gateways, ACK is still transmitted by a single gateway in LoRa Network. HAT-LoRa provides the augmented reception opportunity of ACK via the simultaneous transmissions of identical ACK in multiple spreading factors. The proposed method reduces the expected transmission times of ACK double gateway environment as well as single gateway environment, by 55 and 60% in maximum, by 35% and 40% in average, in a single- and double-gateway environment, respectively. Especially, it outperforms under the environment where the distance between end device and gateways are similar to each other.

• Journal of Korea Trade
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• v.24 no.7
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• pp.29-37
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• 2020

Purpose - This paper empirically investigates the relationship between country governance quality and worker remittances from foreign countries. Because remittances can be a source of funds for economic development and smoothing economic crises in developing countries, the related topic has been a concern for policy-makers and academic researchers. This paper divides the motives of remittances into altruistic and investment motives through existing papers, and then considers the governance quality the remittance receiving country as one of the determinants of remittances. Design/methodology - Our empirical model considers whether governance quality can affect the volume of remittances, and uses altruistic and investment factors studied in the literature. To do this, a two-step approach is taken. First, the panel data are examined via pooled OLS, random effects, and Tobit estimation. Second, the paper reduces six governance indicators into one variable, Governance, using the principal component technique (PCA) for a robustness check. Findings - The main findings can be summarized as follows. The negative governance variable in the estimation results shows a lower governance quality that induces workers to send savings to their home countries. This means that a country with poor governance quality seems to have more remittance inflows from abroad. It also reveals that poor governance quality is more relevant to an altruistic motive rather than an investment motive, in general. The positive per capita GDP variable shows the investment motive for developed countries. Originality/value - Existing papers have focused on various factors related to the motives of remittances. However, governance quality effects on remittance inflows have not been fully studied so far. This paper considers governance quality in an estimation equation explicitly as one of the determinants of remittances. This area of study is needed, in theory and empirically, in order to fully understand the relationship between governance and remittances.

• Current Optics and Photonics
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• v.6 no.2
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• pp.171-182
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• 2022

A single-photon laser and mid-wave infrared (MWIR) common aperture optical system was designed and developed to detect and range a long-distance civil aviation aircraft. The secondary mirror of the Ritchey-Chretien (R-C) optical system was chosen as a dichroic lens to realize the design of a common aperture system for the laser and MWIR. Point spread function (PSF) ellipticity was introduced to evaluate the coupling efficiency of the laser receiving system. A small aperture stop and narrow filter were set in the secondary image plane and an afocal light path of the laser system, respectively, and the stray light suppression ability of the small aperture stop was verified by modeling and simulation. With high-precision manufacturing technology by single point diamond turning (SPDT) and a high-efficiency dichroic coating, the laser/MWIR common aperture optical system with a 𝜑300 mm aluminum alloy mirror obtained images of buildings at a distance of 5 km with great quality. A civil aviation aircraft detection experiment was conducted. The results show that the common aperture system could detect and track long-distance civil aviation aircraft effectively, and the coverage was more than 450 km (signal-to-noise ratio = 6.3). It satisfied the application requirements for earlier warning and ranging of long-range targets in the area of aviation, aerospace and ground detection systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.117-123
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• 2022

Unlike the satellite-based outdoor positioning system, the indoor positioning system utilizes various wireless technologies such as BLE, Wi-Fi, and UWB. BLE-based beacon technology can measure the user's location by periodically broadcasting predefined device ID and location information and using RSSI from the receiving device. Existing BLE-based indoor positioning system studies have many studies comparing the error between the user's actual location and the estimated location at a single point. In this paper, we propose a technique to evaluate the positioning accuracy according to the movement path or area by applying the entropy analysis model. In addition, simulation results show that calculated entropy results for different paths can be compared to assess which path is more accurate.

• The Korean Journal of Pain
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• v.36 no.1
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• pp.84-97
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• 2023

Background: The concept of high-impact chronic pain (HICP) has been proposed for patients with chronic pain who have significant limitations in work, social life, and personal care. Recognition of HICP and being able to distinguish patients with HICP from other chronic pain patients who do not have life interference allows the necessary measures to be taken in order to restore the physical and emotional functioning of the affected persons. The aim was to reveal the risk factors and predictors associated with HICP. Methods: Patients with chronic pain without life interference (grade 1 and 2) and patients with HICP were compared. Significant data were evaluated with regression analysis to reveal the associated risk factors. Receiving operating characteristic (ROC) analysis was used to evaluate predictors and present cutoff scores. Results: One thousand and six patients completed the study. From pain related cognitive processes, fear of pain (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.87-0.98; P = 0.007) and helplessness (OR, 1.06; 95% CI, 1.01-1.12; P = 0.018) were found to be risk factors associated with HICP. Predictors of HICP were evaluated by ROC analysis. The highest discrimination value was found for pain intensity (cut-off score > 6.5; 83.8% sensitive; 68.7% specific; area under the curve = 0.823; P < 0.001). Conclusions: This is the first study in our geography to evaluate HICP with measurement tools that evaluate all dimensions of pain. Moreover, it is the first study in the literature to evaluate predictors and cut-off scores using ROC analysis for HICP.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.202-207
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• 2023

In the case of driving water electrolysis by receiving surplus electricity from solar and wind power generation, operation and stopping must be repeated according to weather fluctuations. When the PEMWE(Polymer Electrolyte Membrane Water Electrolysis) is driven and stopped, the PEM fuel cell is in the same state as the PEM fuel cell due to the residual hydrogen and oxygen, and the high potential of the water electrolysis formed during operation is highly likely to cause degradation of the electrode and membrane even during stopping. In this study, in order to check how much degradation of the electrode and membrane progresses during the repeated driving/shutdown process of PEM water electrolysis, the performance decrease was measured by changing the number of driving/shutdown for 144 hours. Changes in electrode catalyst active area, hydrogen permeability and fluorine emision rate of membranes were analyzed to measure changes in the properties of electrodes and polymer membranes. Overall, the PEMWE performance decreased as the number of stops increased. When stopped 5 times in 144 hours, the IrO_x catalyst activity decreased by more than 30%, and the hydrogen permeability increased by 80%, confirming that both the electrode and the membrane were deteriorated.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.3
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• pp.26-33
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• 2017

Recently container technologies have been receiving attention for efficient use of the cloud platform. Container virtualization technology has the advantage of a highly portable, high density when compared with the existing hypervisor. Container virtualization technology, however, uses a virtualization technology at the operating system level, which is shared by a single kernel to run multiple instances. For this reason, the feature of container is that the attacker can obtain the root privilege of the host operating system internal the container. Due to the characteristics of the container, the attacker can attack the root privilege of the host operating system in the container utilizing the vulnerability of the kernel. In this paper, we propose a framework for efficiently detecting and responding to root privilege attacks of a host operating system in a container. This framework uses a memory trap technique to detect changes in a specific memory area of a container and to suspend the operation of the container when it is detected.