블레이저들의 전파/감마선 상관관계

학위논문(박사) -- 서울대학교대학원 : 자연과학대학 물리·천문학부(천문학전공), 2021.8. Sascha Trippe.Relativistic jets in Active Galactic Nuclei (AGN) are one of the most powerful, persistent sources of energy in the Universe. Investigation of AGN jets is valuable and promising as they play an important role in not only the fields of high-energy astrophysics, but also the evolution of galaxies and clusters. Radio-loud AGNs with their relativistic jets directed toward us (e.g., with a viewing angle of ∼5 degrees), are classified as blazars. One of the well-known characteristics of blazars is strong γ-ray emission originating from their relativistic jets. Because the spatial res- olution of high-energy telescopes is inadequate, however, our understanding of the high-energy emission is limited and thus the production site of blazar γ-ray flares is a matter of active de- bate. To explore the high-energy emission processes and its origin, I studied several individual blazars that recently showed strong γ-ray emission: BL Lacertae, OT 081 (1749+096), 3C 273, and 0716+714. In these studies, I analyzed their multi-wavelength (radio-to-γ-ray) light curves and Very Long Baseline Interferometry (VLBI) datasets on both the time-domain and image- plane to investigate the variations in emission, structure, and kinematics of the jets during a number of γ-ray flaring periods. The blazar BL Lacertae which is the prototypical BL Lac object (a subclass of blazar), was explored using VLBI datasets obtained from the Korean VLBI Network (KVN). Properties of the radio jet are presented with light curves of the radio core (i.e., the VLBI core seen by the KVN) at 22, 43, 86, and 129 GHz. Our observations covered the decaying part of a strong radio flare. The timescales (τ) of the exponential decays show the following relationship: τ ∝ ν−0.2 , with ν being observing frequency. This is much shallower than the one expected from opacity effects (i.e., the core shift). Simultanous multi-frequency observations of the KVN allow us to perform spectral analysis of the radio emission. The spectral indices versus time and radio frequency, support the models of recollimation shocks (Marscher et al. 2008) and the generalized shock evolution (Valtaoja et al. 1992). OT 081 is a blazar with a compact radio jet. In many VLBI images, the source shows a simple point-like feature without any notable extended structures. It had been consistently bright at radio wavelengths (e.g., a few Jy), but without noteworthy strong γ-ray outbursts. However, there was a historically strong γ-ray outburst in 2016 in this source. To investigate this phenomenon, multi-waveband data were used: KVN and OVRO (radio), ASAS-SN (opti- cal), Swift-XRT (X-ray), and Fermi-LAT (γ-ray). It was revealed that the 2016 γ-ray outburst is highly correlated with emission at lower frequencies from radio to X-ray. By using VLBA observations, we found that this γ-ray event was accompanied by the emergence of a moving polarized knot from the radio core which propagates further downstream of the flow. Combin- ing all the evidence, we conclude that the radio core is the origin of the γ-ray outburst. Blazars can be divided into two subclasses: flat-spectrum radio quasars (FSRQ) and BL Lac objects, based on the presence/absence of broad optical emission lines. Recent studies sup- ported that γ-rays of FSRQs originate from a region beyond the broad-line region (BLR), sug- gesting distances of a few parsecs from the central engine where the radio core is thought to be located. Motivated by this, I investigated two recent γ-ray outbursts of the FSRQ 3C 273 which is one of the most powerful and famous blazars. Analysis were done with data obtained from the ALMA, VLBA, and Fermi-LAT. In order to check the correlation between radio and γ-ray emission, the discrete correlation function (DCF) was employed. Our results indicate that the compact features (i.e., multiple standing shocks) are responsible for the observed γ-ray outbursts in the jet of 3C 273. 0716+714 is known to have extreme variability over the entire electromagnetic spectrum. Our preliminary findings of an unusual anti-correlation between radio and γ-ray emission in this source, lead us to start a detailed study of the radio/γ-ray connection in the jet of 0716+714. Archival multi-frequency data (i.e., SMA, Metsähovi, OVRO, Fermi-LAT, and VLBA) were employed and the correlation analysis between the datasets was performed using the techniques of modeling and simulating the light curves. As a result, we found three significant radio-to- γ-ray correlations: two anti-correlations and one positive correlation. We also analyzed VLBA datasets to investigate the parsec-scale jet activity during the γ-ray flares. With all the evidence, we constrain the origin of the γ-ray flares in the jet and suggest internal-shock interactions induced by the passage of a moving disturbance through the radio core as the mechanism behind the observed correlated behaviors. Physics of the relativistic jets in blazars is tricky and complicated due to the extreme physical conditions and various scenarios/possibilities. More detailed observations of the jets with high-resolution VLBI arrays, are currently the best way to resolve the issues of the jet physics. This thesis presents new observational data and results on the nature of blazar γ-ray flares and contributes to the scientific community by supplying the wealth of information for the cases of four remarkable blazars. The individual studies presented in this thesis, conclude as follow: (1) blazar γ-ray flares have multiple emission regions in the jets (i.e., subpc/pc-scales distances from the central black hole) and (2) the propagation of shocks/disturbances along the jet in the subpc/pc-scale regions, causes γ-ray flares (particularly when they pass through the standing shock features; e.g., the radio core).활동성은하핵 (AGN)들의 상대론적 제트는 우주에서 가장 강력하며 영속적인 에너지 소스들 중에 하나이다. 고에너지 천체물리분야 뿐만 아니라 은하와 성단의 진화에 중요한 역할을 함에 따라, AGN 제트들에 대한 연구는 가치있으며 전도유망하다. 전파에서 밝은 AGN (radio-loud AGN)들 중, 그들의 제트가 뻗어나가는 축과 우리의 시선방향 사이의 각도가 매우 작은 (약 5도 이내) AGN들은 블레이저 (Blazar)로써 분류된다. Blazar들의 대표적인 특징 중 하나는 그들의 제트로부터 나오는 강력한 감마선 방출이다. 하지만 고에너지 망원경들의 공간분해능이 충분하지 못하기 때문에, 그러한 고에너지 빛 방출에 대한 우리의 이해는 제한되어 있고, 이에 따라 Blazar 감마선 폭발의 기원은 현재 활발한 논쟁 중에 있다. 그러한 고에너지 빛의 방출기작과 기원을 탐구하기 위해서, 본 저자는 최근 강한 감마선 방출을 보인 몇 개의 개별 Blazar들을 연구하였다: BL Lacertae, OT 081 (1749+096), 3C 273, 그리고 0716+714. 이 연구들에서 본 저자는 감마선 폭발 기간 동안에 제트들의 빛, 구조, 그리고 운동학이 어떻게 변화하는지를 조사하였으며, 이를 위해 그들의 다파장 (전파-감마선) 변광곡선 및 최장기선 간섭계 (VLBI) 데이터들을 시간도메인과 이미지면 위에서 분석하였다. Blazar의 한 유형인 BL Lac object에 속하며, 또한 해당 타입의 원형이기도 한 BL Lacertae가 한국 VLBI 관측기인 KVN를 이용해 연구되어졌다. 22, 43, 86, 그리고 129 GHz에서 얻어진 전파코어의 변광곡선을 이용하여 얻어진 제트의 특성들이 나타내어졌다. 우리의 관측데이터는 하나의 강력한 전파 폭발의 감쇄 부분을 포함한다. 지수함수적 감쇄의 시간규모 (tau) 들은 다음의 관계식을 따른다: tau 비례 nu^-0.2, nu는 관측주파수를 나타낸다. 이는 불투명도 효과 (Core shift)로부터 예상되는 결과에 비해 매우 얕다. KVN의 다주파수 동시관측은 전파 방출 빛에 대한 분광학적 분석을 가능하게 해준다. 시간과 전파 주파수에 대한 분광지수 (Spectral index)의 변화는 Recollimation shock 모델과 Generalized shock 모델들을 지지한다. OT 081은 조밀하고 소형인 제트를 지닌 Blazar이다. 많은 VLBI 이미지들에서 해당 제트는 바깥쪽으로 연장된 눈에 띄는 구조들 없이 단순한 포인트와 같은 형태의 구조를 보여준다. 이 소스는 주목할 만한 감마선 폭발없이 전파에서 지속적으로 밝아왔었다. 그러나 2016년도에 이 타겟소스에 대해서 역사적으로 강력한 감마선 폭발이 발생하였었다. 이 현상을 조사하기 위해, 다파장 데이터들이 사용되었다: KVN과 OVRO (전파), ASAS-SN (광학), Swift-XRT (엑스선), 그리고 Fermi-LAT (감마선). 2016 감마선 폭발이 낮은 주파수대 (전파부터 엑스선까지)의 방출 빛들과 상당한 상관관계를 가지고 있음이 드러났다. VLBA 관측데이터를 이용함으로써, 우리는 또한 이 감마선 폭발이 전파코어로부터 나와 제트의 하류로 전파/이동해나가는 편광 컴포넌트 (Knot)의 출현을 수반했었음을 찾았다. 이러한 모든 증거들을 조합해봄으로써, 우리는 전파코어가 감마선 폭발의 기원이라 결론지었다. Blazar들은 두 가지 유형으로 나뉘어 질 수 있다: 넓은 광학 방출선의 존재/부재에 따라, Flat-Spectrum Radio Quasar (FSRQ) 그리고 BL Lac object. 근래의 연구결과들은 FSRQ들로부터 나오는 감마선들이 Broad-Line Region (BLR) 너머의 지역에서 기원함을 시사했었다. 이는 전파코어가 위치해 있을 것으로 여겨지는, 중앙의 블랙홀로부터 몇 파섹 (parsec) 떨어진 거리를 암시한다. 이러한 아이디어에 착안하여, 본 저자는 가장 강하며 유명한 Blazar들 중 하나인 3C 273 (FSRQ)로부터 발생한 최근의 두 감마선 폭발들을 조사하였다. 분석은 ALMA, VLBA, 그리고 Fermi-LAT 데이터들을 이용하여 수행되어졌다. 전파와 감마선 변광곡선 사이의 상관관계를 알아보기 위해, Discrete Correlation Function (DCF)가 사용되었다. 우리의 결과들은 매우 조밀한 Multiple standing shock들이 3C 273의 제트 안에서 관측된 감마선 폭발들의 기원임을 나타낸다. 0716+714는 모든 전자기파 영역에서 극적인 변광성을 보이는 것으로 알려져 있다. 우리의 사전조사결과로 밝혀진 해당 소스에서의 전파와 감마선 방출 빛 사이의 역상관관계 (anti-correlation)는 우리가 0716+714 제트 안에서 전파/감마선 연관성에 대한 자세한 연구를 개시하게 되는 동기가 되었다. 기록 보관된 (archival) 다파장 데이터들 (SMA, Metsahovi, OVRO, Fermi-LAT, 그리고 VLBA)이 사용되었으며, 데이터들 간의 상관관계 분석은 변광곡선들의 모델링과 시뮬레이션을 이용해 수행되어졌다. 그 결과, 우리는 세 개의 중대한 전파/감마선 상관관계를 찾았다: 두 개의 역상관관계들과 하나의 양적 상관관계. 우리는 또한 감마선 폭발들이 발생하는 동안 파섹 규모에서의 제트가 어떠한 활동성을 보이는지를 알아보기 위해 VLBA 데이터를 분석하였다. 결과들로부터 얻어진 모든 증거를 토대로 우리는 제트 내에서 감마선 폭발들의 기원을 한정하고, 관측된 상관관계들의 배경기작으로써 이동하는 섭동이 전파코어를 지나면서 유발되는 Internal-shock interaction을 제안한다. 극적인 물리적 상태와 다양한 시나리오 및 가능성들 때문에, Blazar의 상대론적 제트들에 대한 물리는 복잡하며 까다롭다. 고분해능 VLBI 어레이들을 통한 제트의 자세한 관측은 현재 제트물리에서의 쟁점들을 해결할 가장 좋은 방법이다. 본 학위논문은 Blazar 감마선 폭발들의 특성에 대한 새로운 관측적 데이터와 결과들을 보여주며, 4개의 주목할 만한 Blazar들의 경우들에 대하여 풍부한 정보를 제공함으로써 학계에 기여한다. 본 학위논문에 수록된 개별 연구들은 다음과 같은 결론을 내린다: (1) Blazar의 감마선 폭발들은 제트 내에서 다중 방출 영역을 가진다 (중앙 블랙홀로부터 subpc/pc 규모의 거리) 그리고 (2) subpc/pc 규모의 거리에서 제트의 하류를 따라 전파해나가는 Shock/섭동들의 이동이 감마선 폭발을 유발한다 (특별히 그들이 Standing shock 구조들을 지나갈 때).I. Introduction 1 1.1 Radio jets in Active Galactic Nuclei (AGN) 1 1.1.1 Active Galactic Nuclei 1 1.1.2 Formation of AGN jets 3 1.1.3 Jet structures and evolution 6 1.1.4 Beaming effects 13 1.1.5 Importance in astrophysics 16 1.2 Multi-waveband observations of AGN 18 1.2.1 Very Long Baseline Interferometry 18 1.2.2 Fermi-LAT 25 1.3 High energy gamma-ray emission in blazars 28 1.3.1 Nonthermal emission 28 1.3.2 The radio/γ-ray connection 32 1.4 Thesis outline 37 II. The Millimeter-Radio Emission of BL Lacertae During Two γ-Ray Outbursts 39 2.1 Introduction 40 2.2 Observation and Data reduction 41 2.3 Results 45 2.3.1 Radio morphology of BL Lac seen by the KVN 46 2.3.2 Radio Light Curves 48 2.3.3 Spectral Indices and Spectrum of the Core 51 2.4 Discussion 53 2.4.1 Variability and Cooling Time Scales 55 2.4.2 Shock Evolution in The Core Region 59 2.4.3 The Radio-γ-Ray Connection 60 2.5 Summary 63 III. Exploring The Nature of The 2016 γ-Ray Emission in The Blazar 1749+096 65 3.1 Introduction 66 3.2 Observations and Data 67 3.2.1 KVN 22/43/86/129 GHz & VLBA 43 GHz 67 3.2.2 OVRO 15 GHz 68 3.2.3 ASAS-SN 69 3.2.4 Swift-XRT 69 3.2.5 Fermi-LAT 69 3.3 Results and Analysis 71 3.3.1 Multi-waveband light curves 71 3.3.2 Multi-wavelength flux correlations 72 3.3.3 LAT γ-ray photon indices 75 3.3.4 Linear polarization at 43 GHz 77 3.3.5 Flux evolution near the core 79 3.4 Discussion 82 3.4.1 γ-ray activity 82 3.4.2 Multi-wavelength correlations 83 3.4.3 Origin of the γ-ray outburst 83 3.4.4 The enhanced γ-ray emission in 2016 October 86 3.5 Summary 86 IV. Investigating The Connection between γ-Ray Activity and The Relativistic Jet in 3C 273 during 2015–2019 89 4.1 Introduction 90 4.2 Observations 91 4.2.1 Fermi-LAT 91 4.2.2 ALMA band3 92 4.2.3 VLBA 43 GHz 92 4.3 Results 94 4.3.1 Light curves 94 4.3.2 Photon indices from weekly and monthly γ-ray light curves 97 4.3.3 Correlation between the radio and γ-ray light curves 99 4.3.4 Parsec-scale jet near the 43 GHz core 102 4.3.5 Polarization 106 4.4 Discussion 108 4.4.1 Positional variations of the stationary components 108 4.4.2 2016 γ-ray outburst 109 4.4.3 2017 γ-ray outburst 112 4.4.4 γ-ray spectra 114 4.5 Summary 115 V. Radio and γ-Ray Activity in The Jet of The Blazar S5 0716+714 117 5.1 Introduction 118 5.2 Observations 120 5.2.1 cm-wavelength data 120 5.2.2 SMA 230 GHz (1.3 mm) 120 5.2.3 γ-ray flux 120 5.3 Results 121 5.3.1 Radio and γ-ray light curves 121 5.3.2 Correlation analysis 121 5.3.2.1 Long-term correlation with the 37 GHz data 121 5.3.2.2 Optimization of the probable time ranges 125 5.3.2.3 DCF curves over the T1, T2, and T3 periods 136 5.3.3 Jet kinematics 140 5.4 Discussion 149 5.4.1 Internal shock interactions 149 5.4.2 Frequency dependence in the time lags 151 5.4.3 Timing of the knot ejections in T1 and T2 153 5.4.4 Location of the γ-ray production site 154 5.4.5 Evolution of the parsec scale jet 155 5.5 Summary 157 VI. Conclusion 161 Bibliography 167 Appendix 183 A Appendices for Chapter4 183 A.1 Gaussian model-fit parameters 183 요약 189 감사의 글 193박

긍정적 사건에 대한 추상적-구체적 반추를 중심으로

본 연구는 추상적 반추 집단과 구체적 반추 집단에서 심리적 웰빙의 중요한 지표인 긍정적인 미래 예측이 어떤 차이를 보이는지를 검증하기 위한 목적으로 수행되었다. 이를 위해 만 18세 이상 성인 268명을 대상으로 온라인 설문조사를 실시하고 스크리닝 과정을 거쳐 우울하지 않은 상태로 판별된 83명을 대상으로 ZOOM프로그램을 이용해 비대면 실험을 진행하였다. 온라인 사전 측정을 마친 참여자는 추상적 반추 집단과 구체적 반추 집단에 무선 배정된 후 연구자와 일대일로 반추 조작 면담을 실시하였다. 조작 면담이 완료된 후 사후 반추 검사를 실시해 반추의 조작이 유의하게 일어났는지 확인하였다. 반추검사 완료 후 참가자는 긍정적 미래 예측 수준을 평정하였다. 불성실한 응답을 한 6명을 제외한 77명의 자료가 최종 분석에 사용되었으며 집단 간 동질 성 검사를 위해 독립표본 t-검정을 실시하였고 긍정반추 성향이 긍정적 미래 예측에 미치는 영향을 확인하기 위하여 성별, 집단, 긍정정서 변화량, 긍정반추를 변인으로 하는 다중회귀분석을 실시하였다. 또한 긍정적 미래 예측이 집단 간 어떤 차이를 보이는지 확인하기 위해 독립표본 t-검정을 실시하였다. 먼저 긍정반추가 긍정적 미래 예측에 미치는 영향을 다중회귀분석으로 분석한 결과, 긍정반추가 긍정적 미래 예측에 영향을 미치는 유일한 변인임이 검증되었다. 이를 통해 우울하지 않은 일반인들은 긍정적인 자기 자질 혹은 긍정정서 경험에 대해 반복적으로 사고하는 경향이 높을수록 긍정적인 미래가 올 가능성을 높게 평가한다는 것을 확인할 수 있었다. 또한 추상적 반추 집단과 구체적 반추 집단의 긍정적 미래 예측을 비교한 결과 추상적 반추 집단에서 긍정적 미래 예측 수준이 유의미하게 높은 것이 밝혀졌다. 두 집단이 서로 독립적이고 동질적으로 구성되어있다는 것 또한 확인되어 다른 요인들이 아닌 집단 간 반추방식의 차이가 긍정적 미래 예측에 유의미한 차이를 만들어냈다는 것이 확인되었다. 본 연구는 지금까지 크게 관심을 받지 못했던 긍정정서 반응양식, 특히 긍정 반추의 개인차와 긍정적인 미래 예측을 실험적으로 연구했다는 의의가 있다. 또한 반추의 처리방식이론을 부정적 상황에 대한 반추가 아닌, 긍정적 반추에서 확인했다는 학술적 의의가 있으며 실제 상담 장면에서 긍정정서 경험을 활용해 내담자의 심리적 웰빙을 도모할 수 있는 방법을 제시했다는 상담 실제적 의의가 있다. 주요어: 긍정적 미래 예측, 긍정 반추, 반추방식, 추상적 반추, 구체적 반추This study was conducted with the aim of verifying the difference in positive future prediction, an important indicator of psychological well-being, in abstract and concrete rumination groups. An online survey was conducted on 268 adults aged 18 and older, and a non-face-to-face experiment was conducted on 83 people who were determined not depressed through the screening process. After completing online pre-measurements, participants were assigned to either the abstract rumination group or the concrete rumination group, which the researcher then conducted a one-on-one rumination manipulation interview. After the manipulation interview was completed, a posterior rumination test was conducted to verify that the significance of the rumination manipulation. After the completion of the rumination test, participants rated the level of positive future prediction. Data from 77 people, excluding six who responded insincerely, were used for the final analysis. Independent sample t-tests were conducted for homogeneity tests between groups, and multiple regression analyses were conducted with gender, group, positive affect, and positive rumination. An independent sample t-test was also conducted to determine how positive future predictions differ between groups. First of all, a multi-regression analysis of the impact of positive reflection on positive future prediction confirmed that positive reflection is the only variable that affects positive future prediction. This confirmed that the higher the tendency of ordinary people to think repeatedly about positive self-qualities or positive emotional experiences, the higher the possibility of predicting a positive future. Furthermore, a comparison of the positive future predictions of the abstract rumination group and the concrete rumination group revealed significantly higher levels of positive future prediction in the abstract rumination group. It has also been confirmed that the two groups are independent and homogeneous from each other, indicating that difference in rumination methods between groups, rather than other factors, have created a significant difference in positive future predictions. The results of this study is significant in that it sheds light on the difference between positive rumination and positive future prediction, twon important factors which have not received much attention so far. There is also an academic significance in that the processing-mode theory of rumination was identified in positive rumination, not in reflection on negative situation. This study also presented a method of promoting the psychological well-being of clients by utilizing positive affect experience in actual counseling scenes. Keywords: Positive Future Prediction, Positive Rumination, Processing Mode Theory, Abstract Rumination, Concrete RuminationI. 서 론 1 1. 연구의 필요성 및 목적 1 2. 연구 문제 및 연구 가설 6 II. 이론적 배경 8 1. 긍정적 미래 기대와 심리적 웰빙 8 2. 반추 10 1) 반추의 정의 10 2) 적응적 반추와 부적응적 반추 11 3. 반추와 미래예측 14 1) 부정적 상황에 대한 반추와 미래예측 14 2) 긍정적 상황에 대한 반추와 미래예측 15 III. 연구방법 21 1. 연구 대상 21 2. 연구 도구 22 3. 실험 절차 27 4. 분석 방법 29 IV. 연구결과 30 1. 결과분석을 위한 자료검토 30 2. 긍정적 미래예측에 긍정반추가 미치는 영향 32 3. 반추방식에 따른 긍정적 미래예측 차이 33 Ⅴ. 논 의 35 1. 요약 및 논의 35 2. 연구의 의의 및 시사점 38 3. 연구의 제한점 및 후속연구 제언 40 참고문헌 42 부록 51 Abastract 76석

A Primary Study on the Development of Evaluation Model for Marine Traffic Safety Assessment

Collision between Xing Guang No.7 and Neo Blue which happened in front of the Incheon lock gate indicates that Korean coastal water is classified as dangerous area due to heavy traffic in confined waters. This may lead to severe accident such as collision, grounding, sinking and environmental pollution. According to the Marine Traffic Safety Law, revised in 2009, Marine Traffic Safety Diagnosis System is introduced to secure the safe navigation, prevent the marine accident and to maximize the efficiency of the port. The diagnosis system aims to investigate, measure and evaluate the effect of the various development project such as the construction of bridge and/or piers, etc. and to reflect the diagnostic results for the safe navigation. In the process of this system, the most important part is the marine traffic safety assessment, and evaluation model is required in order to implement the assessment. However, the evaluation model used in Korea is highly limited, and these models are made in foreign countries such as Japan. There are some problems to apply these models to Korean coastal waters. So the development of the proper evaluation model for Korea is required as early as possible. The purpose of this research is implementing marine traffic assessment of Korean coastal waters by using ES(Environmental Stress) model which is formal assessment model for marine traffic flow simulation in the Diagnosis System and IWRAP(IALA Waterway Risk Assessment Program) recommended by IALA, and analyze the results for the basic reference to develop independent evaluation model.제 1 장 서 론 1 1.1 연구의 배경 및 목적 1 1.2 연구의 방법 2 제 2 장 해상교통 안전진단제도의 개념과 절차 4 2.1 해상교통 안전진단의 용어 정의 4 2.1.1 해상교통의 개념 4 2.1.2 안전의 개념 4 2.1.3 진단의 개념 5 2.2 해상교통 안전진단제도 6 2.2.1 해상교통 안전진단의 개념 6 2.2.2 해상교통 안전진단 절차 9 제 3 장 해상교통 안전성 평가 절차 및 평가모델 조사 11 3.1 해상교통 안전성 평가의 개념 11 3.2 해상교통 안전성 평가 절차 12 3.2.1 해상교통현상 파악 13 3.2.2 해상교통현상 기술 13 3.2.3 해상교통현상 예측 14 3.2.4 해상교통현상 재현 14 3.2.5 해상교통현상 평가 15 3.3 해상교통 안전성 평가모델 16 3.3.1 IWRAP 16 3.3.2 ES Model 22 3.3.3 PAWSA 26 3.3.4 FSA 30 3.3.5 US Model 35 3.3.6 일본의 안전대책 평가 가이드라인 36 3.3.7 기타 평가모델 39 3.3.8 종합 분석 40 제 4 장 IWRAP 및 ES Model을 활용한 울산항 해역 해상교통 안전성 평가 42 4.1 기초 자료 조사 42 4.1.1 자연 환경 42 4.1.2 항행 환경 44 4.2 IWRAP을 이용한 울산항 해상교통 안전성 평가 46 4.2.1 Leg 지정 46 4.2.2 교통량 및 분산치 입력 48 4.2.3 기타 변수 입력 57 4.2.4 안전성 평가 결과 분석 58 4.3 ES Model을 이용한 울산항 해상교통 안전성 평가 60 4.4 해양사고 통계자료 비교 분석 62 제 5 장 결 론 6

Detection of Intestinal Protozoa in Korean Patients Using BD MAX Enteric Parasite Panel and Seegene Allplex Gastrointestinal Parasite Assay

Background: Intestinal protozoan infection is one of the main causes of gastrointestinal diseases. Protozoa are usually detected by direct smear microscopy, concentration techniques, or special stains; however, these techniques are labor-intensive and require well-trained technicians. Therefore, molecular techniques involving polymerase chain reaction (PCR) have been developed to satisfy the need for unbiased and rapid ana lytical methods with high sensitivity and specificity. In this study, the BD MAXTM Enteric Parasite Panel (EPP) (Becton, Dickinson and Company, USA), designed to detect Cryptosporidium parvum and/or hominis, Giardia lamblia, and Entamoeba histolytica, and the AllplexTM Gastrointestinal Para site Assays (AGPA) (Seegene Inc., Korea), designed to detect Cryptosporidium species, G. lamblia, E. histolytica, Blastocystis hominis, Dientamoe ba fragilis, and Cyclospora cayetanensis were compared to determine whether any of these assays could become a useful tool for detecting intes tinal protozoan infections in Korea. Methods: We investigated 295 fecal samples using EPP and AGPA. Then we confirmed the positive results with the conventional and nested PCR. Consistent detection by conventional PCR, nested PCR, and one of the multiplex panels was considered “true positive.” Results: Out of 295 samples, 17 were true positives for B. hominis and 2 were true positives for E. histolytica. EPP detected parasites in only two samples owing to its design; however, its true positive detection rate was 100% (2/2). AGPA detected parasites in 24 samples with 79.2% (19/24) true positives. Conclusions: The incidence of protozoan, especially B. hominis, infection may be more prevalent than expected. AGPA could be an effective tool for screening protozoan infections.ope

The First Case of Ochrobactrum pseudogrignonense Bacteremia in Korea

ope

A Case Report of Transfusion-associated Circulatory Overload

Transfusion-associated circulatory overload (TACO) is recently becoming more important than transfusion-related acute lung injury (TRALI) in terms of the number of patients with definite diagnosis as well as its prognosis. In order to diagnose TACO, it is helpful to recognize early the symptoms suspicious of transfusion reaction through electronic medical record system and computer network, and this will be of help for obtaining samples for brain natriuretic peptide (BNP) measurement before and after the onset of transfusion reaction. We report a case in which a transfusion reaction was diagnosed as TACO. A 62-year-old woman was admitted to the emergency room due to bleeding tendency. Two fresh frozen plasma units and one unit of leukocyte-reduced red blood cells were transfused. Blood pressure increased during transfusion, and the chest X-ray showed findings suggestive of newly developed pulmonary edema. N-terminal prohormone of BNP (NT-proBNP) test was carried out using the specimens in refrigerated storage. Compared with the NT-proBNP level measured 12 hours before the transfusion, that measured 6 hours after the transfusion was markedly increased (>48 fold of pre-transfusion level). As a result, this case was diagnosed with TACO.ope

Determination of Colistin Resistance by Simple Disk Diffusion Test Using Modified Mueller-Hinton Agar

Background: Colistin has become a last-resort antibiotic for the management of multidrug-resistant gram-negative bacteria. The disk diffusion test is cheap and easy to perform but may be unreliable for colistin susceptibility testing due to poor diffusion of the large colistin molecule. An improved agar diffusion test would increase the reliability of colistin susceptibility testing. This study aimed to modify Muller-Hinton agar (MHA) to improve colistin diffusion in agar. Methods: MHA was modified by reducing the agar concentration from 100% to 30% and supplementing with protamine. We tested 60 gram-negative clinical isolates of Pseudomonas aeruginosa (N=27) and Acinetobacter calcoaceticus-baumannii complex (N=33). Disk diffusion test results were interpreted based on minimum inhibitory concentrations determined by broth microdilution. Results: The modified MHA yielded the best performance metrics, including 94.7% sensitivity, 100% specificity, and an area under the curve of 0.995 (95% confidence interval, 0.982-1.000), P<0.001, at a cut-off point of 13 mm. Conclusions: A reduction of the agar concentration from 100% to 30% and the addition of protamine improved colistin diffusion in agar and allowed routine colistin susceptibility testing in a clinical microbiology laboratory, but should be handled with caution.ope

Evaluation of the Analytical Performance of Atellica CH 930 Automated Chemistry Analyzer

Background: Recently, a new automated chemistry analyzer, Atellica CH930 (Siemens, Germany), was introduced. It automatically measures internal quality control (QC) materials according to a pre-determined schedule. For this purpose, the instrument has space for storage of QC materials. We evaluated the analytical performance of chemistry items by using the Atellica system. Methods: The precision of 29 items was evaluated with three levels of QC materials with two storage methods. We stored the QC materials in the dedicated storage space in the instrument during the precision evaluation period. In addition, we aliquoted and stored the materials in the refrigerator, and then loaded the material in a timely manner. Linearity, carry-over, and agreement with current methods were also evaluated. Results: The within-laboratory coefficient of variation (CV) of most items, except for total CO2 (tCO2), was within 5.0% in both QC storage methods without significant differences in CV between storage methods. The CV of tCO2 was 5.2%, 5.8%, and 5.1% at three different levels when the QC materials were stored in a dedicated space in the instrument. The linearity was acceptable, showing <5% nonlinearity. Although good agreement was observed for most items, some items, such as calcium, total bilirubin, aspartate transaminase, and chloride, showed unequivalent results. Conclusions: Atellica CH930 showed acceptable precision, linearity, and agreement in routine chemistry items. The automatic QC function using the storage device has no problem with stability or precision. It can reduce the manual process, allowing technicians to focus on reviewing the QC results and reporting reliable results.ope

A Case of Panagglutination on Antibody Identification in a Multiple Myeloma Patient Receiving Daratumumab

Herein, we report a patient showing panagglutination in the unexpected antibody identification test after the administration of daratumumab. The patient was a 66-year-old woman who had undergone multiple cycles of chemotherapy and autologous peripheral blood stem cell transplantation for treating multiple myeloma; however, despite treatment, she had relapsed. Therefore, daratumumab, on clinical trials in Korea, started to be administered. After administration of daratumumab, the result of antibody screening test was positive, on the contrary to the result prior to the administration. Moreover, all positive reactions were shown in the antibody identification to the panel cells. After destroying CD38 antigens on the surface of RBCs using DTT, negative results were obtained. Daratumumab?a novel therapeutic human CD38 monoclonal antibody that can be used as targeted immunotherapy?is an FDA-approved drug for treating multiple myeloma. Because CD38 is expressed not only on myeloma cells, but also on red blood cells (RBCs), the use of daratumumab might lead to RBC agglutinations, and thereby resulting in false-positive results on the pre-transfusion tests. Therefore, caution is needed in case of a patient receiving daratumumab. Furthermore, additional test using DTT is required, especially when panagglutination was shown in the antibody identification test, as in this case.ope

A Structural Model of the Relationship between Perceptions of Organizational Politics and Organizational Commitment with Organizational Cynicism as a Mediator: Exploring the Negative Factors Affecting the Organizational Commitment of Local Government Employees

조직몰입은 조직의 경쟁우위를 확보하기 위한 중요 수단으로 인식되면서 이의 다양한 영향변인들에 대한 연구가 이루어져 왔지만 부정적 영향요인에 대한 연구는 소수에 불과하다. 본 연구는 조직정치지각 및 조직냉소주의가 조직몰입의 부정적 영향변수로 기능할 것으로 가정하여, 이 들 영향 및 결과 변인들간의 구조적 관계를 실증적으로 분석하는 데 목적을 둔다. 이를 위해 경남지역 관료 221명을 분석 대상으로 하였다. 분석 결과, 조직정치지각과 조직냉소주의는 조직몰입(가치 및 근속몰입)의 부정적 영향변인으로 기능한다는 것이 확인되었으며, 특히, 조직냉소주의는 영향변인과 결과변인을 부분 매개하는 기능도 존재하는 것으로 나타났다. 따라서 본 연구는 행정 서비스의 질적 제고를 위해서는 관료들의 자발적이고 헌신적인 노력에 부정적으로 작용하는 조직정치지각과 조직냉소주의와 같은 요인들을 배제할 수 있는 조직 분위기 형성이 전제되어야 한다는 것을 경험적으로 입증하였다는 점에서 의미를 가진다