• 한국산학기술학회논문지
• /
• 제7권5호
• /
• pp.784-787
• /
• 2006

배기가스 재순환장치는 디젤엔진에서 질소산화물을 저감시키는 기술로서 알려져 있다. 그러나 시스템 적용시 연료소비와 입자상물질을 증가시키기 때문에 기술 적용하는데 있어서 상당히 어려움이 있다. 그래서 실린더내의 연소시스템을 고려한 최적의 배기가스순환 비율을 산정하는 것은 매우 중요하다. 따라서 본 논문은 여러 가지의 EGR율을 변화시키면서 연소와 배기가스에 미치는 영향을 조사했다.

• 한국정밀공학회지
• /
• 제10권3호
• /
• pp.125-132
• /
• 1993

On this study, magnetic force versus input currents is analyzed by modeling taper plunger type proportional electromagnet of ISC valve using the permernce method. And, the reliabiliy of simulation is verified by comparing the experimental values with the calaulate magnetic force. From the result of this study, it is found that the taper angles at plunger and core, the length of air gap between plunger and yoke are the prumary factors in designing taper plunget type proportional electromagnet. Magnetic force is decreased as a whole according to increasing the air gap between pluger and yoke, and vise versa. But, the magnetic force is not proportional to current, when the air gap is very small. In case of decreasing the taper angle of pluger, the stroke range of plunger where magnetic force is proportional to current becomes farther from core.

• Journal of Korea Trade
• /
• 제27권5호
• /
• pp.41-62
• /
• 2023

Purpose - This paper examines whether the imposition of countervailing duties by the United States on undervalued foreign currency is legally consistent with the WTO's SCM Agreement. Design/methodology - The study uses a methodology that involves analyzing relevant WTO agreements, prior panel reports, Appellate Body decisions, and other legal documents. Findings - The findings suggest that to impose countervailing duties, certain legal requirements must be met, including financial contribution, benefit, and specificity. The paper also notes that when calculating the benefits of undervalued foreign currency, losses from import activities due to currency undervaluation must be considered. Additionally, classifying all exports to the US under specific industries or business groups is likely to be inconsistent with the SCM Agreement. Originality/value - Even the US countervailing measures on exchange rate subsidies may not comply with WTO regulations due to incorrect calculation of benefits and a lack of specificity, however, it suggests that when intervening in the foreign exchange market, the measures should aim to achieve only minimum policy goals.

• 대한치과기공학회지
• /
• 제12권1호
• /
• pp.15-21
• /
• 1990

This research was to investigate and study on 92 Dental Technicians who had had some experience of working or being employed at dental craft-shops or craft-rooms in Seoul area and had transferred to other types of occupation, with regard to their reasons for changing their profession. For an approach to the study, some questionnaires and interview including 3 aspects of in quiriesmental, economic and social backgrounds-were administered, and major findings are as follows ; 1. The ages in which transferring to other kinds of job happened occurred mostly from 20 to 30(78.26%) an a group of subjects whose ages ranged from 20 to 30 years old. And, with regard to their experience of working or being employed at dental craft-shops or craftrooms, the transfer of their profession to the other kinds mosty happened in a group of subjects(94.56%) whose experience of working in the dental field is less than 4 years. 2. The reason of transfer with reference to the mental background was mostly mattered in a group that expressed "Excessive Work Duties"(34.78%), and most lowly mattered in a group of subjets who had "Certain Relations with Dentists"(8.70%). Thus, it appeared that the biggest reason of transfer by the mental background was, due to the excessive duty work, not to have Sufficient time to be usualized by dental technicians for their own purpose. 3. With reference to the economical background, a group that declared there was "No Wage Standards in Ratio to Their Labor" was the most in the separation rate as shown 45.56%. And, a group suspecting "No Guarantee for Their Living after Retirement" Showed a separation rate, 9.78%. In other words, the reason for transfer was that they did not receive due wage according to their amount of labor. 4. With reference to the social background, a group making a subject for no good working environments or conditions had a separation rate, 41.30%, which was the most among others, and a group with a subject of "The Rarity of Employment because of Excessive Supply of Dental Technicians" had the rate, 10.87%, which was the lowest. This meant that the major cause of transfer by the social background was a phenomenon for dental technicans to escape from unclean working places.

• 한국산학기술학회논문지
• /
• 제18권11호
• /
• pp.72-77
• /
• 2017

현대 사회에서 조명은 인간 중심적인 자연 조명의 변화를 연출하고 에너지 소비 절감과 효율적인 관리를 위하여 IT 기술과 LED를 결합한 형태로 개발 되고 있다. 따라서 본 논문에서는 Arduino Due와 Bluetooth 및 Zigbee 무선통신 기술을 이용하여 3000K Warm LED와 6000K Cool LED로 구성된 LED 조명의 색온도 및 밝기를 제어할 수 있는 LED 조명 제어 시스템을 제안하였다. Arduino Due는 Duty rate을 조절하여 조명의 색온도를 여러 단계로 조절 할 수 있도록 하였고, 1:N 다중통신이 가능한 Zigbee 통신을 이용하여 많은 조명을 제어할 수 있도록 하였다. 그리고 Bluetooth 통신을 이용하여 스마트폰 어플리케이션으로 LED 조명을 손쉽게 제어할 수 있도록 하여 사용자의 편리성을 증대시켰다. 본 논문에서 구현한 무선통신 기반의 LED 조명제어 시스템은 3067K~5960K의 다양한 색온도 제어와 조도 제어를 통하여 인간 중심적인 조명을 연출할 수 있을 뿐만 아니라 소비전력을 줄일 수 있어 자연 친화적인 조명 시스템으로 활용될 수 있을 것으로 사료된다.

• 한국콘텐츠학회논문지
• /
• 제16권5호
• /
• pp.732-745
• /
• 2016

본 연구는 지방자치단체 조례분석을 통해 장애인생산품 우선구매 활성화방향을 제시하는데 목적이 있으며, 2015년 7월 현재 지방자치단체가 제정 또는 입법예고한 조례 44건을 조례의 각 항목을 분석하였다. 분석결과를 살펴보면 첫째, 전국 지자체 중 44개 지자체에만 조례가 제정되어(18.1%) 더 많은 지자체의 조례제정이 필요하다. 둘째, 조례의 구성내용 분석결과 조례의 목적 및 적용대상기관, 이행계획, 구매 협조 요청, 구매촉진 의무는 대부분의 지방차지단체에서 제시되고 있었다. 반면에 그 외 항목은 명시되지 않은 곳이 많았고 특히, 지자체장의 책무는 30개만 명시되어(68.1%) 있었다. 셋째, 상위 법령 위반(불일치) 조항이 있었다. 넷째, 이행계획 수립을 위한 위원회 설치에 관한 조항은 한 곳도 명시되지 않았다. 우선구매 확대를 위해 계획단계에서부터 학계, 현장, 장애인당사자가 포함된 위원회 설치의 검토가 필요하다. 다섯째, 적극적인 우선구매를 위한 조례 항목의 신설이 필요하며, 효과적인 생산 유통 판매 기반마련을 위한 규정이 필요하다. 마지막으로, 중앙정부가 지자체의 장애인생산품 우선구매 관련 조례와 실적 등을 모니터링하고 이를 개선해 나가기 위한 노력이 요구된다.

• Korean Journal of Radiology
• /
• 제24권3호
• /
• pp.259-270
• /
• 2023

Objective: It is unknown whether artificial intelligence-based computer-aided detection (AI-CAD) can enhance the accuracy of chest radiograph (CR) interpretation in real-world clinical practice. We aimed to compare the accuracy of CR interpretation assisted by AI-CAD to that of conventional interpretation in patients who presented to the emergency department (ED) with acute respiratory symptoms using a pragmatic randomized controlled trial. Materials and Methods: Patients who underwent CRs for acute respiratory symptoms at the ED of a tertiary referral institution were randomly assigned to intervention group (with assistance from an AI-CAD for CR interpretation) or control group (without AI assistance). Using a commercial AI-CAD system (Lunit INSIGHT CXR, version 2.0.2.0; Lunit Inc.). Other clinical practices were consistent with standard procedures. Sensitivity and false-positive rates of CR interpretation by duty trainee radiologists for identifying acute thoracic diseases were the primary and secondary outcomes, respectively. The reference standards for acute thoracic disease were established based on a review of the patient's medical record at least 30 days after the ED visit. Results: We randomly assigned 3576 participants to either the intervention group (1761 participants; mean age ± standard deviation, 65 ± 17 years; 978 males; acute thoracic disease in 472 participants) or the control group (1815 participants; 64 ± 17 years; 988 males; acute thoracic disease in 491 participants). The sensitivity (67.2% [317/472] in the intervention group vs. 66.0% [324/491] in the control group; odds ratio, 1.02 [95% confidence interval, 0.70-1.49]; P = 0.917) and false-positive rate (19.3% [249/1289] vs. 18.5% [245/1324]; odds ratio, 1.00 [95% confidence interval, 0.79-1.26]; P = 0.985) of CR interpretation by duty radiologists were not associated with the use of AI-CAD. Conclusion: AI-CAD did not improve the sensitivity and false-positive rate of CR interpretation for diagnosing acute thoracic disease in patients with acute respiratory symptoms who presented to the ED.

• Journal of Trauma and Injury
• /
• 제20권2호
• /
• pp.77-82
• /
• 2007

Purposes: There have been many efforts to improve the service of emergency centers. In spite of these, no evidence is showing any landmark advancement of emergency services, especially in the hospital stage, exists. We need some efficient standard criteria to evaluate emergency service in the hospital stage, and a useful method might utilize the overcrowding index. We want to know the change in the overcrowding index at a regional emergency center after injury area administration. Injury area means an area in which only an assigned duty physician manages patients with injuries such as those from traffic accidents, falls, assualts, collisions, lacerations, amputations, bums, intoxication, asphyxia, drowning, animal bites, sexual assualts, etc. Methods: We started to operate an injury area in our emergency department from late 2004, and from January to June in 2004 and in 2005, we collected patients' data, age, sex, assigned department, and result from hospital order communication system to figure out overcrowding indices and result indices. We found the daily number of patients, the turnover rate, the admission rate, the ICU admission rate, the emergency operation rate, the ED stay duration, and the ED patient volume to be overcrowding indices. Also we found the withdrawal rate, the transfer rate, and mortality to be result indices. We compared these indices between 2004 to 2005 by using a t-test. Results: There was a significant increase in the daily number of visiting patients in 2005, overcrowding indices, such as the turnover rate, the admission rate, the ICU admission rate, and the emergency operation rate, also showed statistically significant increases in 2005 (P<0.001). As for the result indices, there was a noticeable decrease in the number of withdrawals (11.77/day in 2004 to 4.53/day in 2005). Conclusion: Operating an injury area in a mildly overcrowded local emergency center is beneficial. Evaluating the effect of operating an injury area and it's impact on hospital finances by conducting a similar study analyziing patients for a longer duration would be valuable.

• 보건행정학회지
• /
• 제14권1호
• /
• pp.1-23
• /
• 2004

This study was carried out to investigate the activities and job satisfaction of public health doctors in charge of community health programmes. Subjects were 138 public health doctors charged with community health project, registered in the roll of public health doctors, made out by Central Supporting Team for the District Health Work in 2002. Data was obtained from Ninety-six public health doctors. The response rate was 70%. The survey was conducted from March to April in 2003 bye-mail. The items of the questionnaire consisted of general characteristics of participants, understanding of their activities, support system, job satisfaction, and suggestions to improve the system. Collected data was analyzed using PC-SPSS 10.1. Descriptive analysis, t-test, and ANOVA test were used. The results are as follows: Most of the respondents showed a low participation rate in community health services, but they agreed to the importance of their activities and the necessity to modify and improve the system. 70% of the respondents were dissatisfied with their jobs. The participation in health planning and programmes of health center, and the degree of acceptance of their opinion from health center workers were significantly related to their job satisfaction. The participation rate of the public health doctors having specialty, in community health services is higher than that of the others. In terms of the supports for system operation, the reflection of one's intention in job arrangement process, education and public relation of this system, and the administrative and financial supports made significant differences in the job satisfaction and the accomplishment of their duty. The respondents hoped that the administrative and financial supports for public health doctors in charge of community health programmes should be reinforced to motivate them. They also wanted that they could keep from being overloaded with clinical services. They favored to conduct home visit, community diagnosis, health planning, and health promotion programs as their appropriate activities. From these results, we suggest some strategies to motivate and empower the public health doctors in charge of community health programmes.

• 한국전기전자재료학회논문지
• /
• 제18권12호
• /
• pp.1133-1138
• /
• 2005

In this study, we have prepared, as the pluse power source, a commercially supplied Li-ion battery with a capacity of 700 mAh and AC resistivity of 60 md at 1 kHz and nonaqeous asymmetric hybrid capacitor composed of an activated carbon cathode and MCMB anode, and have examined the electrochemical characteristics of hybrid capacitor and the pulse performances of parallel connected hybrid capacitor/Li-ion battery source. The nonaqueous asymmetric hybrid capacitors constituted with each stack number of pairs composed of the cathode, the porous separator and the anode electrode were housed in Al-laminated film cell. The 10 stacked hybrid capacitor, which was charged and discharged at a constant current at 0.25 $mA/cm^2$ between 3 and 4.3 V, has exhibited the capacitance of 108F and the lowest equivalent series resistance was 32 $m{\Omega}$ at 1 kHz. On the other hand, the enhanced run time of Li-ion battery assisted by the hybrid capacitor was obtained with increasing of current density and pulse width in Pulse mode. The best improvement, $84\;\%$ for hybrid capacitor/Li-ion battery was obtained in the condition of a 7C-rate pulse (100 msec)/0.5C-rate standby/$10\;\%$ duty cycle.