공적연금의 최저생계 보장 효과에 대한 장기 전망

권혁진,류재린,Kwon, Hyukjin,Ryu, Jaerin 한국통계학회 2015 응용통계연구 Vol.28 No.4

본 연구는 동학적 미시모의실험(Micro-simulation) 모형인 MMESP(ver. 2.1)를 활용하여 절대빈곤선으로 간주되는 최저생계비를 기준으로 공적연금 수급액수준을 장기적으로 전망 평가한다. 즉, 본 논문에서 제시하는 노인빈곤율은 공적연금소득만을 고려한 전망치임을 주의할 필요가 있다. 그 주요 결과는 다음과 같다. 첫째, 공적연금액의 장기적 변화는 경제성장효과와 제도효과로 분해할 수 있다. 두 효과를 모두 고려하는 경우, 공적연금액이 최저생계비 이하인 노인가구는 2040년대에 20% 정도수준까지 감소한다. 그러나 경제성장효과를 제외한 제도효과만을 고려하는 경우 노인빈곤율은 장기적으로 90% 내외 수준에 이를 것으로 전망된다. 둘째, 기초연금을 A값의 10% 수준으로 고정한다고 할지라도 경제성장효과를 제외한 공적연금 제도 효과만을 보면, CPI에 연동하는 현행 제도에 비해 노인빈곤율을 10%p 정도 더 축소시킬 뿐이다. 셋째, 현행 국민연금의 급여산식에는 소득수준과 가입기간의 현실적인 상관관계가 고려되지 못함으로써 소득계층간 연금급여의 소득대체율이 역전될 가능성이 높다. 넷째, 2007년 개혁으로 소득대체율이 인하되지 않았다면 현행 체계(국민연금+기초연금)에 비해 과거 체계가 노인빈곤 완화 측면에서는 더 효과적일 수 있다. 즉, 개혁 이전의 제도 하에서는 국민연금만으로도 노인빈곤율은 약 70% 수준까지 축소되었을 것이다. 이것은 2007년 개혁을 통한 연금재정 상의 이득을 얻기 위해 지불한 비용이다. 연금개혁의 올바른 평가는 사회적 편익과 비용을 동시에 고려할 때 가능하다는 점에서 기존 논의에 대한 재검토와 향후 발전적인 논의가 필요하다. This study examines the long-term prospects for a minimum living guarantee by public pensions for the elderly using a dynamic micro-simulation model. "Elderly poverty" here is an estimate calculated by considering only the public pension income and it means how public pension affects the minimum living guarantee for the elderly. The main results are: First the impact of the public pension system on elderly poverty can be decomposed into economic growth and institutional effect. When considering both effects, the absolute poverty rate of the elderly will be reduced to 20% by the year 2040. But when considering the institutional effect(except economic growth effect), that rate is expected to be a long-term level of around 90%. Second, even if the Basic Pension is indexed to 10% of A-value, the elderly poverty rate is only about 10%p to be reduced further, compared to the current CPI-indexed system. Third, current benefit formula for National Pension does not consider the actual correlation of income level and insured period; consequently, the reversal possibility of the replacement rate appears likely. Fourth, the reform of 2007 improves the sustainability of the National Pension; however, it deteriorates the adequacy of the pension policy, i.e., the past system would be better than the current system in regards to a reduction in elderly poverty. Further discussion is needed on aspects of correct pension reform assessments which is difficult to achieve without understanding the comprehensive benefits and costs to society.

돼지 parvovirus불활화(不活化) vaccine 및 중화항체가측정(中和抗體價測定)에 관한 연구(硏究)

권혁진,예재길,이창구,Kwon, Hyock-jin,Yeh, Jae-gil,Lee, Chang-koo 대한수의학회 1988 大韓獸醫學會誌 Vol.28 No.2

A porcine parvovirus inactivated vaccine was prepared and inoculated to 7 piglets and also 8 guinea-pigs, and their serum antibodies were titrated. Twenty-two field serum samples of unvaccinated sows were also tested by SN and HI methods. It was observed that SN test was superior over HI test. Therefore, it is suggested that the SN test could well be used in the detection of serum antibody for PPV in vaccinated pigs.

심리학으로 바라본 항공교통관제사 인지능력

권혁진,Kwon, Hyuk-Jin 한국항공운항학회 2014 한국항공운항학회지 Vol.22 No.4

Aviation safety issues have drawn much attention from the international community due to the growing demand for air travel. Although it is a widely accepted fact that human-related factors are closely linked to aviation safety, there is lack of understanding what roles those factors play in aviation, in the field of air traffic control in particular. It has been reported that the role of air traffic controllers significantly affects air safety. This review will discuss cognitive aspects of expertise in air traffic control including time perception, working memory, reasoning, perception, attention, scanning/vigilance, decision making, and planning with examples of how each aspect can be dealt with in performing air traffic control duties. The relevant studies in psychology have also been briefly reviewed in the interest of enhancing understanding of characteristics of air traffic control tasks and the related human factors. This review concludes with a call for more in-depth research into cognitive factors in air traffic control.

END법을 이용한 돼지콜레라바이러스 및 이에 대한 중화항체가 측정법 개량에 대한 시험

권혁진,윤석민,하용공,조성수,김교종,윤지병,Kwon Hyock-Jin,Yoon Seok-Min,Ha Rung-Kong,Cho Sung-Soo,Kim Kgo-Jong,Yoon Ji-Byung 대한수의사회 1991 대한수의사회지 Vol.27 No.12

The END method for titration of hog cholera virus and its serum neutralizing antibody was improved using ST cells grown and kept in modified media. ST cells were grown in Eagles media containing 0.5$\%$ lactalbumin hydrolysate, 10$\%$</TEX

가중치 윤곽선 검출기를 이용한 저 복잡도 하이브리드 보간 알고리듬

권혁진,전광길,정제창,Kwon, Hyeok-Jin,Jeon, Gwang-Gil,Jeong, Je-Chang 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.3C

예측(predictive) 이미지 코딩에서는 최소 자승법을 기반으로 하는 적응적인 예측기가 에지 주변에 있는 픽셀(pixel)의 예측 결과를 향상시키는데 효과적인 방법으로 알려져있다. 본 논문에서는 가중치 윤곽선 검출기 (weighted edge detector)를 이용한 하이브리드 보간 알고리듬(hybrid interpolation algorithm)을 제안한다 전체적인 계산의 복잡도를 감소시키기 위해서 2차원 선형 보긴(bilinear interpolation)과 에지 방향성을 이용한 보간(edge directed interpolation) 알고리듬을 선택적으로 적용시키는 하이브리드 접근방법을 이용한다. 이런 접근 방법을 2차원 선형 보간 알고리듬과 에지 방향성을 이용한 보간 알고리듬을 적용했을 경우와 비교하기 위해서 PSNR과 SSIM 측정값을 이용하여 객관적이고 주관적인 영상의 화질 비교는 제안한 알고리듬이 비슷한 성능을 나타냄을 보여준다. 또한 제안하는 가중치 윤곽선 검출기를 이용한 하이브리드 보간 알고리듬은 정규화된 CPU 수행 시간을 에지 방향성을 이용한 보간 알고리듬과 비교하면 최대 20배의 복잡도 감소 효과를 얻을 수 있다. In predictive image coding, a LS (Least Squares)-based adaptive predictor is an efficient method to improve image edge predictions. This paper proposes a hybrid interpolation with weighted edge detector. A hybrid approach of switching between bilinear interpolation and EDI (Edge-Directed Interpolation) is proposed in order to reduce the overall computational complexity The objective and subjective quality is also similar to the bilinear interpolation and EDI. Experimental results demonstrate that this hybrid interpolation method that utilizes a weighted edge detector can achieve reduction in complexity with minimal degradation in the interpolation results.

항공부품 프레팅 손상 측정용 시험 장치 개발

권혁진,김경목,Kwon, Hyuk-Jin,Kim, Kyung-Mok 한국항공운항학회 2015 한국항공운항학회지 Vol.23 No.1

In this paper, a fretting testing machine is developed using ball-on-flat test apparatus. Precise micro-slip motion is produced by a linear stage. A relative displacement between a ball and a flat specimen is measured with a laser displacement sensor. Dry friction tests are conducted with AISI 52100 steel balls and cold-rolled high strength steel plates at room temperature and ambient humidity. The evolution of the kinetic friction coefficient is determined. Comparison between measured friction coefficients and those found in the literature is then carried out. Fretting tests with an electro-deposited coating are employed at an amplitude of 0.05 mm. Slip regime is identified with slip ratio. It is demonstrated that a developed testing machine allows determining the friction coefficient under fretting condition.

고령화와 연금: 지속가능성과 적정성에 대하여

권혁진,박유성,Kwon, Hyukjin,Park, Yousung 한국통계학회 2015 응용통계연구 Vol.28 No.4

고령화, 연금, 그리고 관련된 이슈에 대해 총 12편의 엄선된 논문의 내용을 간략하게 정리하였다. 이 12편의 논문은 내용적으로 지속가능성, 연금의 적정성, 연금의 개혁방안으로 분류할 수 있다. 특히, 국민연금제도에 대한 심도 있고 광범위한 논의와 다양한 연금개혁방안은 정책입안자와 연금관련연구자에 많은 도움이 될 것으로 기대한다. We summarize the twelve papers carefully selected for aging, pensions, and related issues, The twelve novel papers are grouped into three categories: sustainability, adequacy, pension reforms. In particular, these twelve papers include depth and extensive discussions for national pension system and present the direction of the various pension reforms. It will be a great help to policy makers and researchers.

항공관제 전문성 수준에 따른 시각정보 판독과 미래정보 예측 차이

권혁진,Kwon, Hyuk-Jin 한국항공운항학회 2015 한국항공운항학회지 Vol.23 No.3

Many studies have shown that having perception of spatial information is important for air traffic control officer (ATCO) since it helps them understand the current situation and predict the situation it leads to. However, little or no research has been done to investigate if there is any difference at the levels of expertise in perceiving spatial information and predicting a prospective situation. This study investigates the difference between expert and novice ATCO groups in how accurately each group of ATCO perceive spatial information such as position, altitude, speed, and flying direction, and predicting such information they will encounter shortly. In completing a task to watch the movement of airplanes displayed on the computer monitor as a blip, the participants were asked to predict the position, speed, and the altitude of the aircraft in a minute by marking on the sector map. The results show that the expert group performed better in accuracy and had tendency to overestimate on position and altitude; however, no significant difference was found between the two groups in terms of reading a flying direction. Therefore reading a flying direction may not be a reliable indicator to judge expertise of ATCO. But the expert group shows better predicting performance by perceiving spatial information such as airplane's position and altitude with feeling on time. The study suggests that it is important to enhance perceptive skills in ATCO training in improving their expertise in predicting accuracy traffic situation, preventing from air collision, and improving productivity for more efficient air traffic flow. A further study on the relationship between the perception of spatial information and the sense of time in predicting future information and effectiveness as an independent factor would contribute to providing more insights into expertise of ATCOs.

Relation between Earthward magnetotail flow and low-latitude Pi2 pulsations

권혁진,김관혁,이동훈,이은상,Kwon, Hyuck-Jin,Kim, Khan-Hyuk,Lee, Dong-Hun,Takahashi, Kazue,Lee, Ensang,Angelopoulos, Vassilis,Park, Young-Deuk 한국천문학회 2012 天文學會報 Vol.37 No.2

It has been suggested that oscillatory earthward bursty bulk flows (BBFs) in the magnetotail are driving Pi2 oscillations on the ground. However, only a few studies examined the BBF-driven Pi2 model. The goal of this study is to establish the relation between BBFs and Pi2s. In order to examine BBF-drive model, we will conduct the timing analysis between BBFs and Pi2s for the intervals during which both Pi2 and BBF are present. In our study BBFs are identified with earthward flow speeds up to 200 km/s from THEMIS probes with a geocentric distance between 7 and 12 RE in the nightside magnetosphere for the interval from January 2008 to March 2008. Pi2 pulsations are identified at three low/mid-latitude ground stations having different local times; Bohyun (L = 1.35, LT ~ UT +9 hr), Hermanus (L = 1.83, LT ~ UT +2 hr) and Carson city (L = 2.00, LT ~ UT -2 hr). It is found that ~28% of BBFs have onset timing nearly identical to Pi2 onset. To investigate whether there is high similarity in the waveform between BBF and Pi2 oscillations, the coherence analysis is applied to the time series of BBF and Pi2 events. We found that there is no high coherence between BBF and Pi2 oscillations. Thus our observations suggest that low-latitude Pi2 oscillations are not directly driven by earthward flow bursts.

사각 덕트 내부 열전달 향상을 위한 요철의 단락 효과

권혁진,우성제,조형희,Kwon, Hyuk-Jin,Wu, Seong-Je,Cho, Hyung-Hee 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.5

The influence of arrangement and length of discrete ribs on heat/mass transfer and friction loss is investigated. Mass transfer experiments are conducted to obtain the detailed local heat/mass transfer information on the ribbed wall. The aspect ratio (width/height) of the duct is 2.04 and the rib height is one tenth of the duct height, such that the ratio of the rib height to hydraulic diameter is 0.0743. The ratio of rib-to-rib distance to rib height is 10. The discrete ribs were made by dividing each continuous rib into 2, 3 or 5 pieces and attached periodically to the top and the bottom walls of the duct with a parallel orientation The combined effects of rib angle and length of the discrete ribs on heat/mass transfer ae considered for the rib angles $({\alpha})\;of\;90^{\circ}\;and\;45^{\circ}$. As the number of the discrete ribs increases, the uniformity of the heat/mass transfer distributions increases. For $(\alpha})=90^{\circ}$, the heat/mass transfer enhancement with the discrete ribs is remarkable, while the heat/mass transfer performances are slightly higher than that of the transverse continuous ribs due to the accompanied high friction loss penalty. For $(\alpha})=90^{\circ}$, the average heat/mass transfer coefficients and the heat/mass transfer performances decrease slightly with the discrete ribs compared to the case of the angled continuous ribs.