강화도의 지질별 지하수 중 자연방사성 물질의 특성

김익현(Ikhyun Kim),김문수(MoonSu Kim),함세영(Se-Yeong Hamm),김현구(Hyunkoo Kim),김동수(Dongsoo Kim),조성진(Seongjin Jo),이헌민(Heonmin Lee),황종연(Jongyeon Hwang),조훈제(Hunje Jo),박선화(Sunhwa Park),정현미(Hyenmi Chung) 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.1

인천시 강화도의 지질별(중생대 화강암, 선캠브리아 편마암, 편암) 지하수의 자연방사성 물질과 수리지화학 성분의 특성을 연구하였다. 이 연구를 위하여, 8년 동안 69개 관정에서 지하수 시료를 채수하였다. 통계 분석을 이용하여 지하수의 수리지화학 성분과 자연방사성 물질의 관계를 분석하였다. 연구 지역 지하수의 수질유형은 Ca(Na)-HCO 3 형으로 나타났다. 우라늄은 3 개 지하수 시료에서 US EPA의 MCL(최대 오염 물질 수준)인 30 ug/L을 초과하였다. 라돈은 28개 지하수 시료에서 US EPA의 제안치인 AMCL(대체 최대 오염 물질 수준)인 4,000 pCi/L을 초과하였다. 모든 지하수 시료의 전알파(Gross-alpha)는 US EPA MCL인 15 pCi/L를 초과하지 않았다. 지하수에서의 우라늄과 라돈의 평균농도는 화강암에서 가장 높고, 그 다음으로 편마암, 편암의 순이다. 편암 지역의 라돈은 HCO 3 와 –0.40, 우라늄은 SO 4 과 0.54의 상관계수를 보였고, 편마암 지역의 경우 라돈은 우라늄과 0.55, 우라늄은 SO 4 과 0.41의 상관계수를 보였다. 요인분석에 의하면, 지질별로 각각 다른 거동특성을 가진다. 전체 지하수의 통계 분석 결과, 우라늄과 라돈 그리고 지화학 성분들 간에는 대체로 특이한 상관성을 나타내지 않았다. 자연방사성 물질의 거동과 운명을 보다 명확하게 이해하기 위해서는 자연방사성 물질의 수리지질학적, 지구화학적, 지질학적 특성에 대한 보다 상세한 연구가 요구된다. Groundwaters in different rock types (Mesozoic granite, Precambrian gneiss, and schist) of Ganghwa island, Incheon City were characterized by using naturally occurring radioactive materials (NORM) and hydrogeochemical constituents. For the study, groundwater samples from 69 wells had been collected over eight years. Statistical methods were applied to relate hydrogeochemical components and NORM in the groundwater samples. The groundwater samples belonged to Ca(Na)-HCO 3 types. The uranium concentrations in three groundwater samples exceeded 30 ug/L of United States Environmental Protection Agency (US EPA) maximum contaminant level (MCL). The radon concentrations in 28 groundwater samples exceeded 4,000 pCi/L (picocuries per Liter) of US EPA alternative maximum contaminant level (AMCL). Gross-alpha in all the groundwater samples did not exceed 15 pCi/L of US EPA MCL. The average concentrations of uranium and radon in groundwater were the highest in granite area, and then gneiss, schist areas in order. In schist area, the correlation coefficient (R) between radon and HCO 3 is –0.40 and R between uranium and SO 4 is 0.54. In gneiss area, the R between radon and uranium is 0.55 and the R between uranium and SO 4 is 0.41. According to factor analysis, each geological area shows different chemical characteristics. The statistical analysis of whole groundwater resulted in nearly no significant relationship among uranium, radon and chemical constituents. Subsequently, more detailed studies on hydrogeological, geochemical, and geological characteristics related to NORM are required to better understand the behavior and fate of NORM.

Experimental Monitoring of Different Human Vital Signal Simultaneously using Novelda Xe-Thru X4M202 IR-UWB RADAR

Jongyeon Kim(김종연),Paulson Eberechukwu,Jaebok Lee(이재복),Sunwoo Kim(김선우) 한국통신학회 2022 한국통신학회 학술대회논문집 Vol.2022 No.2

This paper resents our experimental results on monitoring of human vital signal using Novelda Xe-Thru X4M202 impulse radio ultra-wide band (IR-UWB) radio detection and ranging (RADAR). We have results from simultaneously monitoring of different human vital signs using IR-UWB technology. Therefore, the overall objective of this work is to propose experiment that can effectively detect the breathing rate and heart rate of the human target within the range of IR-UWB RADAR.

Factors associated with rebleeding after coil embolization in patients with aneurysmal subarachnoid hemorrhage

Kim Donghee,Pyen Jinsu,Whang Kum,Cho Sungmin,Jang Yeongyu,Kim Jongyeon,Koo Younmoo,Choi Jongwook 대한뇌혈관외과학회 2022 Journal of Cerebrovascular and Endovascular Neuros Vol.24 No.1

Objective: Aneurysmal subarachnoid hemorrhage (aSAH) has a high mortality rate, and hemorrhage amounts and perioperative rebleeding importantly determines prognosis. However, despite adequate treatment, prognosis is poor in many ruptured aneurysm cases. In this study, we identified and evaluated factors related to perioperative rebleeding in patients with aSAH. Methods: The medical and surgical records of 166 patients that underwent endovascular embolization for a ruptured cerebral aneurysm at a single institution from 2014 to 2016 were retrospectively analyzed to identify risk factors of rebleeding. All patients were examined for risk factors and evaluated for increased hemorrhage by brain computed tomography at 3 days after surgery. Results: This series included 54 men (32.5%) and 112 women (67.5%) of mean age 58.3±14.3 years. After procedures, 26 patients (15.7%) experienced rebleeding, and 1 of these (0.6%) experienced an intraoperative aneurysmal rupture. External ventricular drainage (EVD) (odds ratio [OR] 5.389, [95% confidence interval (CI) 1.171- 24.801]) and modified Fisher grade (OR 2.037, [95% CI 1.077-3.853]) were found to be independent risk factors of rebleeding, and perioperative rebleeding was strongly associated with patient outcomes (p<0.001). Conclusions: We concluded the rebleeding risk after aSAH is greater in patients with large hemorrhage amounts and a high pre-operative modified Fisher grade, and thus, we caution neurosurgeons should take care in such cases. Objective: Aneurysmal subarachnoid hemorrhage (aSAH) has a high mortality rate, and hemorrhage amounts and perioperative rebleeding importantly determines prognosis. However, despite adequate treatment, prognosis is poor in many ruptured aneurysm cases. In this study, we identified and evaluated factors related to perioperative rebleeding in patients with aSAH. Methods: The medical and surgical records of 166 patients that underwent endovascular embolization for a ruptured cerebral aneurysm at a single institution from 2014 to 2016 were retrospectively analyzed to identify risk factors of rebleeding. All patients were examined for risk factors and evaluated for increased hemorrhage by brain computed tomography at 3 days after surgery. Results: This series included 54 men (32.5%) and 112 women (67.5%) of mean age 58.3±14.3 years. After procedures, 26 patients (15.7%) experienced rebleeding, and 1 of these (0.6%) experienced an intraoperative aneurysmal rupture. External ventricular drainage (EVD) (odds ratio [OR] 5.389, [95% confidence interval (CI) 1.171- 24.801]) and modified Fisher grade (OR 2.037, [95% CI 1.077-3.853]) were found to be independent risk factors of rebleeding, and perioperative rebleeding was strongly associated with patient outcomes (p<0.001). Conclusions: We concluded the rebleeding risk after aSAH is greater in patients with large hemorrhage amounts and a high pre-operative modified Fisher grade, and thus, we caution neurosurgeons should take care in such cases.

Raytracing based measurement for V2X communications

Jongyeon Kim,Igbafe Orikumhi,Sunwoo Kim 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.11

Generating real-time data for autonomous vehicle is important to evaluate the vehicular system performance. However, such data collection models can be time consuming and costly. To address this issue, data generation methods using ray tracing software can be employed. In this paper, we measure the received signal power for multiple V2X scenario with varying speeds. The results shows that the optimal signal paths can be obtained from the generated data which can then be used by a machine learning network for V2X beam management.

2층 고속열차 알루미늄 압출재 차체 구조물의 구조안전성 평가

김종연(JongYeon Kim),강승구(SeungGu Kang),신광복(KwangBok Shin),고태환(TaeHwan Ko),유원희(WonHee You) 한국철도학회 2014 한국철도학회 학술발표대회논문집 Vol.2014 No.10

본 논문은 2층 고속열차의 알루미늄 압출재 차체의 구조안전성을 평가하는데 그 목적을 두고 있다. 알루미늄 압출재 차체의 초기 프로파일 형상은 설계변수에 따른 구조해석 결과를 통해 결정하였다. 구조해석을 위한 최적의 요소 크기를 찾기 위해서 해의 수렴성 분석을 수행하였으며, 그 결과를 토대로 유한요소 모델을 생성하였다. 차체의 구조안전성은 철도안전법에 의거하여 상용 유한요소해석 프로그램으로 평가하였다. 해석결과, 철도안전법의 요구조건을 만족시키는 2층 고속열차 알루미늄 압출재 차체의 기본 설계(안)을 도출하였다. The purpose of this paper is to evaluate structural integrity of aluminum extrusion carbody for double deck high-speed train. The initial shape of aluminum extrusion profile for carbody was determined by the results of structural analysis according to the selected design variables. In order to find optimum mesh size for structural analysis of aluminum extrusion carbody, the convergence analysis was conducted and finite element model was made considering result of convergence analysis. The structural integrity was for carbody evaluated by commercial finite element analysis program and Korean Railway safety law. The basic concept of the aluminum extrusion carbody for double deck high-speed trains that satisfies the Korean Railway Safety law was presented through results of analysis.

한국전쟁 이후 북한의 청진 도시계획에 관한 연구 - 피오트르 자렘바의 도시계획 방법론을 중심으로-

김종연(Kim, Jongyeon),정인하(Jung, Inha) 대한건축학회 2020 대한건축학회 학술발표대회 논문집 Vol.40 No.2

Right after the conclusion of Korean war at July 1953, North Korean Government started recovering the destructed cities. The Government asked the other Socialist Countries for help of their recovery projects. As a result, Soviet Union provided technics and machineries for recovering Pyeongyang, East Germany designed the masterplan of Hamheung and Poland planed the city of Chongjin. Among them, the urban planning method of Chongjin shows some differences compared to Pyeongyang and Hamheung. The purpose of this study is to analyze the unique urban planning method of Piotr Zaremba used in Chongjin plan and compare it with general planning methods of Socialist Countries used in Pyeongyang and Hamheung.

퇴적물 입자의 점하중강도지수와 마식율의 관계에 대한 연구

김종연(Jongyeon Kim) 대한지리학회 2008 대한지리학회지 Vol.43 No.6

하천 퇴적물질의 마식은 하상과의 충돌과 퇴적물질 입자간의 충돌에 의하여 발생한다. 하천 퇴적물질의 물리적 강도는 마식에 대한 저항의 정도를 나타내는 것으로 정의할 수 있으나, 이에 대한 실증적인 연구는 큰 진전을 보이지 못해왔다. 본 연구에서는 퇴적물질의 마식에 영향을 미치는 요소들(퇴적물질의 물리적강도, 퇴적물질의 크기, 퇴적물질의 양등)의 관계를 파악하기 위해서 마식기를 이용한 물리적 실험을 실시하였으며, 특히 퇴적물질의 물리적 강도가 마식율에 미치는 영향을 분석하는데 강조점을 두고 있다. 이 실험에서는 266개의 퇴적물을 이용했으며, 퇴적물질의 양과 퇴적물질의 평균 무게에 따라 11개의 소집단으로 나눠 실험하였다. 각 실험은 1시간 단위로 이루어 졌으며 퇴적물질은 최장 8시간 동안 마식되었다. 마식율은 각 실험단계마다 퇴적물질 입자 무게의 변동으로 측정하였으며, 총 2,128번의 측정이 이루어졌다. 퇴적물질의 물리적 강도는 시험이 종료한 뒤에 파괴하중을 측정하여 계산한 점하중강도지수를 통해 측정하였다. 퇴적물질의 점하중강도지수는 마식율과 음의 상관이 있는 것으로 나타났으나, 두 변수들 간의 회귀식의 설명율(R²)은 0.22로 나타났다. 퇴적물질의 전반적인 마식은 실험 초기에는 빠르게 진행되지만, 풍화각이 제거된 뒤에는 마식율이 급감하는 경향을 보여주고 있다. 풍화각을 제거하는 초기 단계에는 퇴적물질의 물리적 강도와 마식율의 관계가 미약하지만 이후로 점점 설명율이 상승한다. 이 실험 결과에 의하면 퇴적물질의 물리적 강도는 마식율의 결정적인 설명변수가 아닐 수 있으며, 물리적 속성 이외에도 퇴적물질의 운반조건 등이 마식율에 큰 영향을 주는 것으로 판단된다. Sediment abrasion in rivers is caused by the interaction between bedrock channel bed and sediment particles transported through the river. Abrasion rate of sediment particles in rivers is controlled by two major factors; Sediment transport conditions including hydraulic conditions form the erosive forces and physical and chemical strengths of the particles form a resistance force against abrasion and other erosional processes. Physical experiments were performed to find the role of each variable on sediment abrasion process. Total 266 sediment particles were used in this experiment. All sediment particles were divided into 11 independent sediment groups with sediment particle size and sediment loads. Each sediment groups were abraded in tumbling mill for up to 8 hours. Changes in weight were recorded by run and total: 2,128 cases of abrasion rate were recoded. Physical strength of rock particles was measured with point load strength index. It is found that sediment abrasion rate has a negative functional relationship point load strength index (Ia(50)). (R²=0.22). It was suggested that physical strength of sediment particles set the “maximum possible abrasion rate’. As sediment flux increases, abrasion rates of sediment particles with similar point load strength index were changed. It could be concluded that not only physical characteristics of sediment particles, but also sediment transport conditions control sediment abrasion rates.

정보 제공을 통한 건물에너지 절약 행동 유발에 관한 실험

김성수(Kim Sung-Su),김소연(Kim So-Yeon),김용훈(Kim Yong-Hun),임종연(Lim Jongyeon) 한국태양에너지학회 2020 한국태양에너지학회 논문집 Vol.40 No.6

As a measure to reduce energy consumption in buildings, the high performance of the outer skin and the high efficiency of the facility system are attracting attention to induce changes in the behavior of the inmates. A methodology in the field of behavioral science, so-called nudge, is being considered as an energy-saving measure. However, most of the existing empirical experiments are aimed at housing, which can be attributed to the fact that individual energy conservation acts as an economic incentive, making it easier to achieve its effect. This study reports the results of empirical experiments on energy saving in public spaces by nuts, which, so far, includes few examples. The experiment was conducted on 33 people in a university laboratory. The existing energy consumption patterns were measured for one month; only a few workers were regularly informed of the energy usage for two months, and the resulting changes in the energy consumption patterns were measured. The provision of energy consumption information has shown to increase the probability of energy saving, and it is particularly effective in promoting the energy-saving behavior of those willing to save energy.

Unusual Enhancements of NmF2 in Anyang Ionosonde Data

Yun, Jongyeon,Kim, Yong Ha,Kim, Eojin,Kwak, Young-Sil,Hong, Sunhak 한국우주과학회 2013 Journal of Astronomy and Space Sciences Vol.30 No.4

Sudden enhancements of daytime NmF2 appeared in Anyang ionosonde data during summer seasons in 2006-2007. In order to investigate the causes of this unusual enhancement, we compared Anyang NmF2’s with the total electron contents (GPS TECs) observed at Daejeon, and also with ionosonde data at at mid-latitude stations. First, we found no similar increase in Daejeon GPS TEC when the sudden enhancements of Anyang NmF2 occurred. Second, we investigated NmF2’s observed at other ionosonde stations that use the same ionosonde model and auto-scaling program as the Anyang ionosonde. We found similar enhancements of NmF2 at these ionosonde stations. Moreover, the analysis of ionograms from Athens and Rome showed that there were sporadic-E layers with high electron density during the enhancements in NmF2. The auto-scaling program (ARTIST 4.5) used seems to recognize sporadic-E layer echoes as a F2 layer trace, resulting in the erroneous critical frequency of F2 layer (foF2). Other versions of the ARTIST scaling program also seem to produce similar erroneous results. Therefore we conclude that the sudden enhancements of NmF2 in Anyang data were due to the misrecognition of sporadic-E echoes as a F-layer by the auto-scaling program. We also noticed that although the scaling program flagged confidence level (C-level) of an ionogram as uncertain when a sporadic-E layer occurs, it still automatically computed erroneous foF2’s. Therefore one should check the confidence level before using long term ionosonde data that were produced by an auto-scaling program.

Seasonal variation of environmental stable isotope in the shallow groundwater from multi-level wells at an agricultural area

HyunKoo Kim,MinKyeong Lee,InKyu Shin,Gyeongmi Lee,Moonsu Kim,JongYeon Hwang,SunHwa Park,HunJe Jo,Tae Seung Kim 한국분석과학회 2017 학술대회논문집 Vol.2017 No.5