• 한국정보통신학회논문지
• /
• 제19권7호
• /
• pp.1539-1545
• /
• 2015

GPS (global positioning system)는 지구 궤도를 도는 여러 GPS 위성의 신호를 수신하여 이들 신호의 수신 시간 차이를 이용하여 자신의 절대 위치를 알아내는 시스템으로 민간 목적뿐만 아니라 군용 목적으로도 널리 사용되고 있다. 특히 군용 시스템에서는 무기 등에도 사용되기 때문에 안정적인 GPS 수신이 민간보다 더 중요하다. 하지만 GPS는 사용 주파수가 알려져 있기 때문에 나쁜 의도로 인위적인 재밍신호를 송출하여 GPS 시스템을 무력화 시킬 수 있다는 문제가 있다. 이에 재밍신호를 제거하고 GPS 신호만을 안정적으로 수신하기 위해 GPS 수신기에 다중 안테나를 설치하고 빔 널링 기술을 이용하여 재머만을 제거하는 기술이 많이 연구되어 왔다. 이러한 기술 중에서 본 논문에서는 MVDR (minimum variance distortionless response) 기술에 기반하여 새로운 적응형 빔 제어 기술을 제안한다. 제안하는 방식은 위성 방향으로의 빔은 훼손하지 않으면서 재머 방향으로는 적응적으로 널을 형성하여 재머를 효과적으로 제거한다. 제안하는 방식의 성능은 컴퓨터 모의실험을 통해 검증한다.

• 한국전기전자재료학회논문지
• /
• 제29권9호
• /
• pp.559-564
• /
• 2016

This study examined the malfunction mode of the HCMOS IC under narrow-band high-power electromagnetic wave. Magnetron is used to a narrow-band electromagnetic source. MFR (malfunction failure rate) was measured to investigate the HCMOS IC. In addition, we measured the resistance between specific pins of ICs, which are exposed and not exposed to the electromagnetic wave, respectively. As a test result of measurement, malfunction mode is shown in three steps. Flicker mode causing a flicker in LED connected to output pin of IC is dominant in more than 7.96 kV/m electric field. Self-reset mode causing a voltage drop to the input and output of IC during electromagnetic wave radiation is dominant in more than 9.1 kV/m electric field. Power-reset mode making a IC remained malfunction after electromagnetic radiation is dominant in more than 20.89 kV/m. As a measurement result of pin-to-pin resistance of IC, the differences between IC exposed to electromagnetic wave and normal IC were minor. However, the five in two hundred IC show a relatively low resistance. This is considered to be the result of the breakdown of pn junction when latch-up in CMOS occurred. Based on the results, the susceptibility of HCMOS IC can be applied to a basic database to IC protection and impact analysis of narrow-band high-power electromagnetic waves.

• 한국운동역학회지
• /
• 제26권4호
• /
• pp.369-375
• /
• 2016

Objective: The purpose of this study was to investigate the possibility of injuries and the types of movement related to damage by body parts, and to prepare for prevention of injuries and development of a training program. Method: For this study, the experiment was conducted according to levels of 60 percentages (ST) and 85 percentages (MA) and 10 subjects from the Korean elite national weightlifting team were included. Furthermore, we analyzed joint moment and muscle activation pattern with three-dimensional video analysis. Ground reaction force and EMG analyses were performed to measure the factors related to injuries and motion. Results: Knee reinjuries such as anterior cruciate ligament damage caused by deterioration of the control ability for the forward movement function of the tibia based on the movement of the biceps femoris when the rectus femoris is activated with the powerful last-pull movement. In particular, athletes with previous or current injuries should perceive a careful contiguity of the ratio of the biceps femoris to the rectus femoris. This shows that athletes can exert five times greater force than the injury threshold in contrast to the inversion moment of the ankle, which is actively performed for a powerful last pull motion and is positively considered in terms of intentional motion. It is activated by excessive adduction and internal rotation moment to avoid excessive abduction and external rotation of the knee at lockout motion. It is an injury risk to muscles and ligaments, causing large adduction moment and internal rotation moment at the knee. Adduction moment in the elbow joint increased to higher than the injury threshold at ST (60% level) in the lockout phase. Hence, all athletes are indicated to be at a high risk of injury of the elbow adductor muscle. Lockout motion is similar to the "high five" posture, and repetitive training in this motion increases the likelihood of injuries because of occurrence of strong internal rotation and adduction of the shoulder. Training volume of lockout motion has to be considered when developing a training program. Conclusion: The important factors related to injury at snatch include B/R rate, muscles to activate the adduction moment and internal rotation moment at the elbow joint in the lockout phase, and muscles to activate the internal rotation moment at the shoulder joint in the lockout phase.

• Journal of Chest Surgery
• /
• 제44권1호
• /
• pp.51-57
• /
• 2011

Background: Up to now, lobectomy, bilobectomy and pneumonectomy combined with extensive lymph node dissection have been regarded as the standard procedures for non-small cell lung cancer (NSCLC). In high-risk patients, however, limited resection (LR) has been attempted as a salvage procedure, and, recently, indication for LR has been extended to selected cases with early-stage NSCLC. Material and Methods: Among the 773 patients who underwent surgical procedures for NSCLC in Seoul National University Bundang Hospital from May 2003 to December 2008, 43 patients received LR. Medical records of these patients were retrospectively reviewed. Results: Mean age at operation was $66.0{\pm}12.4$ years, and there were 30 males. Twenty-five patients underwent conservative limited resection (CLR) and 18 underwent intentional limited resection (ILR). Indications for CLR were multiple primary lung cancer in 9 (9/25, 36%) and severe concomitant diseases in 5 (5/25, 20%). Of these, 6 patients underwent segmentectomy and 19 received wedge resection. During the follow-up period of $28.0{\pm}17.8$ months, 15 patient developed recurrent lung cancer. ILR was selectively performed in lesions almost purely composed of ground glass opacity (${\geq}$95%), or in small solid lesions (${\leq}$2 cm). Of these, 11 patients underwent segmentectomy and 7 underwent wedge resection. During the follow-up period of $31.7{\pm}11.6$ months, no patient developed recurrence. Conclusion: Intermediate-term outcome of LR for early-stage lung cancer is comparable to that of standard operation. For the delineation of the indications and appropriate surgical techniques for LR, prospective randomized multi-institutional study may be expedient.

• 보건행정학회지
• /
• 제28권1호
• /
• pp.87-90
• /
• 2018

Suicide has been a public health issue in many countries, and Korea has ranked highest suicide rate among Organization for Economic Cooperation and Development (OECD) countries over a decade. To address these issues, we updated the recent trends in suicidal ideation and suicide attempts among Korean adults followed by previous data observation. We used data from five sources: Korean National Health and Nutrition Examination (KNHANES, '07-12, '13, '15-16), Korean Community Health Survey (KCHS, '08-09, '13), Korean Wealth Panel Study (KOWEPS, '12-16), Korea Health Panel Survey (KHP, '10-13), and cause of death data from Statistics Korea ('07-16). We used weighted frequencies and trend tests. The rate of suicidal ideation as recent year was 5.10% (KNHANES, '15), 8.95% (KCHS, '13), 2.08% (KOWEPS, '16), and 5.39% (KHP, '13). That of suicide attempts as recent year was 0.59% (KNHANES, '16), 0.41% (KCHS, '13), and 0.08% (KOWEPS, '16). Annual percentage change of suicidal ideation was -2.80% (KNHANES, '07-12), 5.78% (KNHANES, '13-15), 0.62% (KCHS, '08-13), -8.50% (KOWEPS, '12-16), and -10.94% (KHP, '10-13). Annual percentage change of suicide attempts was -3.84% (KNHANES, '07-12), 2.26% (KNHANES, '13-16), -2.53% (KCHS, '08-13), and -20.22% (KOWEPS, '12-16). Annual percentage change of death by intentional self-harm was -0.49% (Statistics Korea, '07-16). Individuals who had lower income level were more likely to experience suicidal ideation and suicide attempts. According to these results, the rate of suicidal ideation and suicide attempts showed the decreasing tendency. However, the suicide rate of Korea has remained higher than that of OECD countries. Thus, continuous data observation and effective policies on suicide are needed.

• 대한임상독성학회지
• /
• 제8권2호
• /
• pp.61-68
• /
• 2010

Purpose: Poisoning is a major health problem for the elderly, and poisoning can cause fatal side effects. However, the characteristics and clinical features of elderly patients with acute poisoning have not been well studied in the previous domestic research. So, we tried to analyze the clinical characteristics and toxic substances of the patients who were 65 years old or older and who were admitted to the regional emergency medical center due to acute poisoning. Methods: We retrospectively reviewed the medical records and poisoning protocols of the patients who were 65 years of age or older and who had with acute poisoning and who visited the ED in our emergency center from January 2005 to December 2009. We collected the demographic information, the gender, the underlying diseases, the causes and toxic substances, the initial presentation, the treatment and the outcomes. Results: A total of 2179 poisoned patients visited the hospital during 5 years, and among them 244 were 65 years of age or older (11.2%). The mean age was $75.6{\pm}6.9$ years and the male:female ratio was 1:1.7. The most common cause of poisoning was suicide (73.4%) and the most common source of poisonous substances was their own drugs. Of the substances used for poisoning, benzodiazepine was the most common drug (25.8%), followed by sedatives other than benzodiazepine (25.4%), insecticide (12.7%), chemical agents (12.3%) and herbicides (8.2%). The most common initial presentation was mental change (64.8%). When comparing the factors between the three elderly groups, there was no difference in gender, the cause, the substances and the underlying disease. The outcomes of treatment included ICU admission (56.1%), a good condition at discharge (12.7%) and admission to a general ward (12.7%). The overall mortality rate was 10.2% for the elderly patients. Conclusion: In this Korean study, unlike the foreign studies, the most common cause of poisoning in elderly patients was intentional poisoning. The admission rate was 68.8% and mortality rate was 10.2%.

• 한국콘텐츠학회논문지
• /
• 제21권9호
• /
• pp.458-470
• /
• 2021

한국의 정책 현실에서는 사회적으로 큰 이슈가 되지만 막상 정책 결정이 이루어지지 않는 경우가 많이 있다. 이렇게 정책 결정이 지연되는 이유로는 적정한 정책 절차를 거치기 위해서 지연되는 경우, 이해관계자의 동의가 이루어지지 않아 지연되는 경우 등도 존재하지만, 이와 같은 사유만으로 정당화되지 않는 정책 지연도 다수 발생하고 있다. 본 연구는 현재 한국의 정책 결정 과정에서 정당화되지 않는 정책 지연은 정부에 의한 의도적인 무의사결정으로 설명할 수 있다는 점을 제시하고자 하였다. 이에 대한 사례로 상암동 롯데복합쇼핑몰을 제시하고, 상암동 롯데복합쇼핑몰 정책 과정을 무의사결정의 시각에서 분석하였다. 엘리트층의 존재, 목적, 정책수단, 정책과정, 결과 등의 요소들을 기반으로 분석한 결과 상암동 롯데복합쇼핑몰 건립 지연 사례는 정부의 적극적이고 전략적인 무의사결정에 의한 것으로 추정될 수 있었다. 소극행정과 구분되는 정부의 전략적인 무의사결정에 대해 향후 다양한 검토가 이루어질 필요가 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권10호
• /
• pp.3627-3641
• /
• 2021

Fintech, which stands for financial technology, is growing fast globally since the economic crisis hit the United States in 2008. Fintech companies are striving to secure a competitive advantage over existing financial services by providing efficient financial services utilizing the latest technologies. Fintech companies can be classified into several areas according to their business solutions. Among the Fintech sector, peer-to-peer (P2P) lending companies are leading the domestic Fintech industry. P2P lending is a method of lending funds directly to individuals or businesses without an official financial institution participating as an intermediary in the transaction. The rapid growth of P2P lending companies has now reached a level that threatens secondary financial markets. However, as the growth rate increases, so does the potential risk factor. In addition to government laws to protect and regulate P2P lending, further measures to reduce the risk of P2P lending accidents have yet to keep up with the pace of market growth. Since most P2P lenders do not implement their own credit rating system, they rely on personal credit scores provided by credit rating agencies such as the NICE credit information service in Korea. However, it is hard for P2P lending companies to figure out the intentional loan default of the borrower since most borrowers' credit scores are not excellent. This study analyzed the voices of telephone conversation between the loan consultant and the borrower in order to verify if it is applicable to determine the personal credit score. Experimental results show that the change in pitch frequency and change in voice pitch frequency can be reliably identified, and this difference can be used to predict the loan defaults or use it to determine the underlying default risk. It has also been shown that parameters extracted from sample voice data can be used as a determinant for classifying the level of personal credit ratings.

• 감성과학
• /
• 제24권1호
• /
• pp.3-10
• /
• 2021

본 연구는 생각/생각회피 과제를 이용하여 의도적 생각회피, 즉 생각억제와 생각대체의 효과를 종합적으로 검증하였다. 이를 위해 연관성이 높지 않은 2음절 단어자극을 선정하고, 단일집단을 대상으로 회상조건(단서회상, 표적회상)과 훈련조건(생각, 생각억제, 생각대체, 기저선)의 정확회상률을 비교하였다. 그 결과, 훈련조건과 관계없이 표적회상에 비해 단서회상의 정확기억률이 높은 것으로 나타났으며, 회상조건과 관계없이 다른 조건에 비해 생각조건의 정확회상률이 높은 것으로 나타났다. 또한 회상조건과 훈련조건의 상호작용 효과의 경향성이 나타났으며, 세부적 검증 결과. 생각억제의 경우, 회상조건 간 차이가 나타나지 않은 반면에 생각대체의 경우에는 표적회상에 비해 단서회상의 정확기억률이 높은 것으로 나타났다. 이러한 결과는 생각억제와 생각대체전략이 모두 의도적으로 생각을 회피하는데 효과적이라는 것과 더불어 생각억제와 생각대체전략이 서로 다른 원리에 의해 발생할 수 있음을 시사한다.

• 한국건축시공학회지
• /
• 제21권2호
• /
• pp.149-156
• /
• 2021

본 연구는 도급공사의 공격적인 저가 수주로 인한 공사비 부족을 만회하기 위해 설계변경 등 자구책이 뒤따르게 되고, 이러한 과정에서 시공상의 하자가 유발될 수 있다는 점에 대하여 재무적 자료를 이용하여 실증분석하는 것을 목적으로 한다. 연구 결과, 공격적인 수주행위로 인한 수주량의 비상적인 증가와 영업이익률 등 수익성 악화는 공사 품질의 저하와 하자 발생으로 이어진다는 것을 확인하였다. 또한 시공눙력이 낮거나 공사 착공 후 설계나 계약 조건을 변경하는 경우 하자발생의 직접적인 원인이 된다는 것도 확인하였다. 공격적인 저가 수주와 하자 발생 사이의 관련성을 확인함으로써, 하자발생을 방지할 수 있는 방안을 마련하는 계기가 될 수 있다.