• Tuberculosis and Respiratory Diseases
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• 제82권3호
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• pp.190-193
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• 2019

Inhaled corticosteroids (ICSs) have been widely used as a key medication for asthma control. However, ICSs have been known to cause respiratory infections, such as pneumonia and pulmonary tuberculosis. Consequently, a dilemma exists regarding recommendation of persistent lifetime use of ICSs to mild asthma patients. Short-acting ${\beta}$-agonists (SABAs) have also been widely used for symptom relief. However, SABAs have been reported to increase the risk of asthma-related death, though incidences have been very rare. Consequently, a dilemma exists regarding recommendation of a SABA alone without an ICS or a controller to asthma patients even with very mild disease. In the real world, asthma patients tend to intermittently use ICS and more likely to be dependent on SABA since many patients want immediate relief of their symptoms. Consequently, a dilemma exists regarding the underuse of ICSs but the overuse of SABAs. One strategy for solving the presented dilemma would be identification of patients with asthma who require persistent use of asthma controllers. Such patients, who may be referred to as "persistent controller users," should continuously receive ICSs, even under controlled states of asthma. Another strategy would be a patient-adjusted, symptom-driven, intermittent-to-regular treatment combining low-dose ICS/rapid-onset long-acting ${\beta}$-agonists instead of using a SABA alone or with low-dose ICS for the asthma patients with mild disease. Both of these two strategies could avoid the risky treatment of a SABA alone without an ICS and could reduce the dose of ICS with the maintenance of asthma control.

• Tuberculosis and Respiratory Diseases
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• 제70권5호
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• pp.416-422
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• 2011

Background: Inhaled corticosteroids (ICSs) are the most essential medication for asthma control. Many reports suggest that the usage of ICSs improves not only the control of asthma symptoms but also prevents exacerbation. We investigated whether increases in ICS prescriptions are associated with decreases in asthma exacerbation in the clinical practice setting. Methods: We retrospectively analyzed the database of adult asthma patients who had visited a tertiary referral hospital, the Asan Medical Center between January 2000 and December 2009. The number of emergency department (ED) visits, admissions, intensive care unit (ICU) care, deaths, and ICS prescriptions were analyzed to evaluate the time trend of asthma exacerbation as a function of the ICS prescription rate during the ten years. Results: The numbers of ED visits, admissions, and episodes of ICU care decreased during the ten years (p<0.001, p=0.033, p=0.001, respectively) while the number of ICS prescriptions increased (p<0.001). We found a correlation between the number of ICS prescriptions and the number of ED visits, admissions, or ICU care. For these outcomes, the correlation coefficients were r=-0.952, p<0.001; r=-0.673, p=0.033; r=-0.948, p<0.001, respectively. Conclusion: The number of ICS prescriptions increased during the past ten years while the number of asthma exacerbations decreased. Our results also showed a negative correlation between the ICS prescription rate and asthma exacerbation in the clinical practice setting. In other words, an increase in ICS prescription may be a major cause of a decrease in asthma exacerbations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.491-492
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• 2008

• Tuberculosis and Respiratory Diseases
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• 제83권1호
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• pp.42-50
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• 2020

Background: Fractional exhaled nitric oxide (FeNO) is regarded as a potential biomarker for identifying eosinophilic inflammation. We aimed to evaluate the clinical implication of FeNO and its influence on inhaled corticosteroids (ICS) prescription rate in Korean chronic obstructive pulmonary disease (COPD) patients. Methods: FeNO level and its association with clinical features were analyzed. Changes in the prescription rate of ICS before and after FeNO measurement were identified. Results: A total of 160 COPD patients were divided into increased (≥25 parts per billion [ppb], n=74) and normal (<25 ppb, n=86) FeNO groups according to the recommendations from the American Thoracic Society. Compared with the normal FeNO group, the adjusted odds ratio for having history of asthma without wheezing and with wheezing in the increased FeNO group were 2.96 (95% confidence interval [CI], 1.40-6.29) and 4.24 (95% CI, 1.37-13.08), respectively. Only 21 out of 74 patients (28.4%) with increased FeNO prescribed ICS-containing inhaler and 18 of 86 patients (20.9%) with normal FeNO were given ICS-containing inhaler. Previous exacerbation, asthma, and wheezing were the major factors to maintain ICS at normal FeNO level and not to initiate ICS at increased FeNO level. Conclusion: Increased FeNO was associated with the history of asthma irrespective of wheezing. However, FeNO seemed to play a subsidiary role in the use of ICS-containing inhalers in real-world clinics, which was determined with prior exacerbation and clinical features suggesting Th2 inflammation.

• 정보보호학회논문지
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• 제30권4호
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• pp.745-756
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• 2020

산업제어시스템이란 전력, 수처리, 교통과 같은 주요기반시설이나, 자동화 공장, 화학 플랜트와 같이 산업분야의 프로세스를 안전하고 효율적으로 모니터링 및 제어하는 시스템을 말한다. 이러한 산업제어시스템을 대상으로 하는 사이버 공격이 성공한다면 큰 인명 피해, 경제적 피해를 유발할 수 있어, 국가단위 해커 집단들의 주요 공격 대상이 될 가능성이 높다. Stuxnet, Industroyer, TRITON과 같은 사이버 공격은 이러한 우려가 실제 현실로 드러난 사례이며, 사이버 공격으로 실제 물리적 피해를 발생시키기 위해 대상 제어시스템에 대한 깊은 지식을 기반으로 개발된 것으로 확인되었다. 따라서 산업제어시스템의 사고조사를 위해서는 사고분석가 역시 제어시스템 운영 프로세스에 대한 지식을 보유하고 제어시스템에 특화된 사고조사 기술을 확보해야 한다. 이를 위해 사이버와 물리적 경계에 위치한 임베디드 제어기기와 같이 사이버 공격의 대상이 될 수 있지만, IT분야에서 사용되지 않아 즉시 활용할 기술이 없는 장치들을 대상으로 하는 사고조사 기술 개발이 필요하다. 이러한 연구 개발의 첫 단계로써 대표적인 임베디드 제어기기인 PLC(Programmable Logic Controller) 4종을 대상으로 PLC의 로깅 기능 및 본 논문에서 제안한 공격 시나리오에서 사고조사에 활용 가능한 로그 생성 여부를 분석한 결과를 제시한다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권3호
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• pp.221-228
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• 2011

This paper describes 250-Mb/s fiber optic transmitter and receiver ICs for plastic optical fiber applications using a$ 0.18-{\mu}m$ CMOS technology. Simple signal and light detection schemes are introduced for power reduction in sleep mode. The transmitter converts non-return-to-zero digital data into 650-nm visible-red light signal and the receiver recovers the digital data from the incident light signal through up to 50-m plastic optical fiber. The transmitter and receiver ICs occupy only 0.62 $mm^2$ of area including electrostatic discharge protection diodes and bonding pads. The transmitter IC consumes 23 mA with 20 mA of LED driving currents, and the receiver IC consumes 16 mA with 4 mA of output driving currents at 250 Mb/s of data rate from a 3.3-V supply in active mode. In sleep mode, the transmitter and receiver ICs consume only 25 ${\mu}A$ and 40 ${\mu}A$, respectively.

• 한국안전학회지
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• 제22권5호
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• pp.27-32
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• 2007

We investigated the damage of the TTL ICs which manufactured five different technologies by artificial microwave. The artificial microwave was rated at a microwave output from 0 to 1000W, at a frequency of 2.45GHz. The microwave power was extracted into a standard rectangular waveguide(WR-340) and TTL ICs were located into the waveguide. TTL ICs were damaged two types. One is breakdown which means no physical damage is done to the system and after a reset the system is going back into function. The other is destruction which means a physical damage of the system so that the system will not recover without a hardware repair. TTL SN74S08N and SN74ALS08N devices get a breakdown and destruction occurred but TTL SN74LS08N, SN74AS08N and 74F08N devices get a destruction occurred. Also destructed TTL ICs were removed their surface and a chip conditions were analyzed by SEM. The SEM analysis of the damaged devices showed onchipwire and bondwire destruction like melting due to thermal effect. The tested results expect to be applied to the fundamental data which interprets the combination mechanism of the semiconductors from artificial microwave environment.

• 정보보호학회논문지
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• 제23권2호
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• pp.329-337
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• 2013

산업제어시스템의 사이버위협 특징은 의도하지 않았다고 하더라도 피해범위가 특정 시스템뿐만 아니라 네트워크의 서비스 제공을 위협하는 수준에 도달했다는 점이다. '보안'의 일부 범위는 단지 테러리스트나 사이버 해커의 고의적인 공격에 대한 시스템의 보호를 포함하지만, 종종 더 큰 피해는 의도적인 공격보다 부주의에 의한 설정 오류 또는 장비고장 등의 비고의적인 행위로 이루어 진다. 본 논문은 고의적 공격, 실수, 장비 고장 및 소프트웨어 문제를 포함한 ICS의 모든 비정상 행위에 대한 분류를 제안하였다. ICS의 비정상 행위 분류 기준은 고의적인 공격뿐만 아니라 부주의한 행동의 공통점과 중요한 특징을 강조하기 위해 선정되었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.33-37
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• 2004

Slotless Permanent magnet Brushless DC Motor(PM BLDC) with the characteristics of high speed and high power density has been more widely used in industrial and automatic machine. Generally, PM BLDC meter is necessary that the three Hall-ICs evenly be distributed around the stator circumference in case of the 3 phase motor. The Hall-ICs are set up in this motor to detect the main flux from the rotor. therefore the output signal from Hall-ICs is used to drive a power transistor to control the stator winding current. However, instead of using three Hall-ICs, if only we used one Hall-IC, we estimate information of the others phase in sequence through a revolving rotor. This paper identified the characteristics and performance by using one Hall-IC for the 3 phase PM BLDC whose six stator and two rotor designed.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 추계학술대회 학술발표 논문집 제14권 제2호
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• pp.192-196
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• 2004

This paper proposes an alternative observation scheme, T-S fuzzy model based indirect adaptive fuzzy observer. Nonlinear systems are represented by fuzzy models since fuzzy logic systems are universal approximators. In order to estimate the unmeasurable states of a given nonlinear system, T-S fuzzy modeling method is applied to get the dynamics of an observation system. T-S fuzzy system uses the linear combination of the input state variables and the modeling applications of them to various kinds of nonlinear systems can be found. The adaptive fuzzy scheme estimates the parameters comprising the fuzzy model representing the observation system. The proposed indirect adaptive fuzzy observer based on T-S fuzzy model can cope with not only unknown states but also unknown parameters. In the process of deriving adaptive law, the Lyapunov theory and Lipchitz condition are used. To show the performance of the proposed observation method, it is applied to an inverted pendulum on a cart.