운임수익과 선박가격 변동이 선박투자결정에 미치는 영향 - 비선형 장기균형관계 -

김현석 ( Hyun Sok Kim ),장명희 ( Myung Hee Chang ) 한국해운물류학회(구 한국해운학회) 2014 해운물류연구 Vol.30 No.4

본 연구는 운임수익과 선박가격 변동을 반영한 선박투자결정모형을 검정하기 위하여 다음의 두 가지에 초점을 두고 분석을 실시하였다. 첫째, 동일한 자산의 가치를 나타내는 신조선가와 중고선가의 변동과 이로부터 발생하는 운임수익과의 관계로 정의되는 선박투자모형을 제시하였다. 둘째, 선박투자자의 행태를 분석에 포함할 수 있는 비선형 모형을 제시하고 분석대상 기간을 경제적 충격에 따른 영향으로부터 구분하여 분석을 실시하였다. 선형분석을 실시한 결과, 선박투자결정모형이 통계적으로 유의한 관계가 존재하지 않는 것으로 나타났지만, 선박에 대한 투자를 유보하는 상황이 발생할 가능성이 존재하는 투자자의 행태를 모형에 포함할 경우에 통계적 유의성이 높은 것으로 나타났다. 이는 해운시황이 급격하게 변동하는 경우 선박에 대한 투자자들의 행태가 상당히 투자유보적일 수 있음을 의미한다. In this study, we have empirically examined ship investment model regarding the relationships between ship price changes and revenues. We focus on following two issues: first, we propose ship investment model, which combines the gap between new building and secondhand ship price with revenues. Second, empirical specification that includes investor’s behaviour is extended to nonlinear framework. We divide the series based on global economic crisis and test the model to the different periods. The empirical results reveal the nonlinear cointegration test that is able to capture investor’s behaviour in shipping market shows very significant for the periods, while linear model is insignificant. This implies investor would be risk neutral when the market condition is drastically changed.

PLZT 세라믹의 상변이 특성에 관한 연구

유주현,홍순석,박창엽 연세대학교 산업기술연구소 1986 논문집 Vol.18 No.2

PLZT electrooptic ceramics of compositions in the range X/65/35 with 5?? X ??9, where X is the mol % La substixuted for lead in a ceramic with a Zr/Ti ratio of 65/35, were fabricated by the two stage sintering technique. For the ceramics, dielectric properties and phase transition were investigated. X-ray diffraction analysis was performed to analize α-β phase transition. For X=5,6, its crystal structure was Rhombohedral in the thermally depoled state as well as the poled state. For 6〈X〈9, phase transition was occured by poling and the intermediate region existed between the paraelectric and ferroelectric states. For X=9, its crystal structure was the same cubic phase in the thermally depoled state and the poled state.

效率的인 指導力 訓練 프로그램의 開發 : 大學生用

陳渭敎,尹正倫,金晟會,石秀隆,文昌鉉 경북대학교 학생생활연구소 1992 學生指導硏究 Vol.25 No.1

고빈도 장기시계열을 활용한 해운산업의 경기변동 구조변화 분석

김현석 ( Kim Hyun-sok ),장명희 ( Chang Myung-hee ) 한국해운물류학회(구 한국해운학회) 2020 해운물류연구 Vol.36 No.2

본 연구는 1985년 1월부터 최근 2020년 4월까지 주별 건화물선 운임지수를 이용하여 해운경기변동 분석에 대한 구조변화 모형의 필요성을 제기한다. 전체 추정자료와 하위 표본기간으로 구분한 분석은 구조단절을 포함하는 비선형(nonlinear) 모형이 적합한 것으로 나타난다. 구체적으로 BS(Binary Segmentation)와 PELT(Pruned Exact Linear Time)를 적용한 평균, 분산에 대한 단절점 추정으로부터 2008년을 전후하여 다수의 변환이 발생하고 있음을 확인하였다. 이는 시계열 자료의 구간단절에 대한 최근의 비선형 분석도 자료의 다양한 구조변환을 적절하게 반영하기 위한 모형으로 확장되어야함을 의미한다. Based on the partial equilibrium frameworks, former studies on economic fluctuations in shipbuilding and shipping industry focus on nonlinear analysis with various factors reflecting structural changes to capture specific the market conditions. This study raises the need for multiple structural change framework for the analysis of shipping market fluctuations based on the weekly dry freight rate from January 1985 to April 2020. The empirical results from full-sample and sub-sample periods shows that a nonlinear analysis including structural change is suitable. Specifically, the estimates with BS(Binary Segmentation) and PELT (Pruned Exact Linear Time) confirm that a large number of breaks have occurred around 2008. The empirical results provided by high-frequency time series show the necessity of the multiple structural change models based on big data and artificial intelligence for shipping market. It is implied in recent nonlinear investigation of time series data that the analysis should extend the models to properly reflect various structural change in the series.

제대동정맥 ECMO를 적용한 염소태아의 혈액가스 및 혈류역학 변화

송창훈(Chang Hun Song),소금영(Geum Young So),이국현(Kook Hyun Lee),박석천(Sok Cheon Pak) 대한산부인과학회 2001 Obstetrics & Gynecology Science Vol.44 No.9

N/A Objectives : The purpose of this study is to establish animal model of extracorporeal membrane oxygenation (ECMO) system that uses membreane type oxygenator and circulation circuit of umbilical artery and vein. Blood gas and hemodynamic changes in the fetal goat undergoing ECMO were also evaluated. Methods : Total 15 pregnant goat had been used to perform extrauterine fetal incubation using ECMO through umbilical artery and vein. Cesarean-section was performed to pregnant goat (35 kg) of 120-130 days of gestation to insert catheters (8 Fr) into the umbilical artery and vein. The tip of inserted catheter's the other end was connected with the circuit system including membrane type oxygenator (Polystan) and roller pump. A total of 300 ml of blood was drawn from donor nonpregnant goat and primed into circuit on the day of surgery. The goat fetus was immersed in a chamber filled with artificial amniotic fluid to monitor blood flow dynamics and blood gas was analyzed. Results : The ECMO system using umbilical cord in the extrauterine incubation of fetal goat was developed and maximum survival of goat fetus was 34.5 hrs (mean survival was 856.6±688 min). Oxygen tension (PO2) in umbilical artery and vein were 20.53±2.54 mmHg, 31.03±13.03 mmHg and oxygen saturation (SO2) in umbilical artery and vein were 46.61±18.14 mmHg, 71.56±15.39 mmHg. Mean blood flow was 176±62 ml/min/kg. Conclusion : We suggest that our experimental model as an extrauterine fetal research could be a reasonable method in future advanced studies. However, longterm survival of extrauterine fetus needs more suitable hemodynamic and blood gas condition supported by further researches.

실습선 한바다호의 운항성능에 관한 연구(II)

정창현(Chang-Hyun, Jung),이윤석(Yun-Sok, Lee) 한국항해항만학회 2008 한국항해항만학회지 Vol.32 No.5

해상 상태가 거칠어짐에 따라 선체동요로 인하여 선박에 승선 중인 승객 및 승무원은 멀미 증상을 호소하기도 하고, 졸음 증상, 어지럼증, 두통 및 복통 등을 초래하기도 한다, 심한 경우에는 생리적으로 회복하기 힘들 정도의 심각한 장애를 겪기도 한다. 또한, 의욕(동기부여) 감소, 숙련도 저하, 인지능력 및 판단력 저하 등 정신적 활동의 지연이나 오류를 유발하는 둥 활동성 및 작업수행 능력이 현저히 떨어지기도 한다. 본 논문에서는 멀미의 발생 맞 작업수행과 관련된 대표적인 국제 표준안을 살펴보았고, 실습선에 승선 중언 실습생들을 대상으로 수차례에 걸쳐 설문조사를 실시하여 승선감을 평가하였다 그 결과, 멀미 중상을 유발하는 주요소가 상하가속도임을 확인하였고. 그 크기(수준)는 0.2g 이상으로 분석되었다. 또한, 속력 또는 침로를 변경하여 파도와의 만남주기가 4~8초의 범위에서 벗어나도록 항해함으로써 멀미 증상을 완화시킬 수 있는 방안을 제시하였다. When a vessel is underway in a heavy weather, passengers and crew suffer from seasickness caused by ship motions such as pitch, heave or roll, or all combined Sickness induces drowsiness, dizziness, headache, stomachache etc, in extreme conditions, they are met with a serious trouble which is physiologically unrecoverable. It results in weakening of spiritual activities or making errors from decrease of motivation, dropping off skills, poor recognition and poor judgement. In this paper, it was examined the international standards concerning the occurrence of sickness and the execution of works, also evaluated the boarding comfort by conducting several times of questionnaire on cadets boarding on the training ship HANBADA As a result, it was confirmed that the main factor of occurring the sickness was the vertical acceleration and the level was more than 0.2g. Also, it was presented the way how to reduce the sickness by changing the speed and/or course in relation to the encounter period.

규칙적인 수영운동과 taurine 섭취가 Seizure 유발 마우스의 해마에서 항산화 효소 및 caspase-3, 8 발현에 미치는 영향

채창훈(Chae Chang-Hun),노종철(Noh Jong-Cheol),이진경(Lee Jin-Kyung),강성환(Kang Sung-Hwan),박석(Park Sok),김현태(Kim Hyun-Tae),박종명(Park Jong-Myoung),안응남(An Eung-Nam),김지연(Kim Ji-Youn) 한국체육과학회 2010 한국체육과학회지 Vol.19 No.2

We investigated changes in the activity of inducing epileptic seizures with PTZ, changes in apoptosis-related factors and the antioxidant defense system in mice. The mice were divided into 4 groups (n=8 for each group) such as the control (PTZ) group, the carnosine-administered (Ca+PTZ) group, the exercise (Ex+PTZ) group and the mixed treatment (Ca+Ex+PTZ) group. The expression of caspase-3, 8 protein was a significant difference in the changes of protein expression between all groups. But the changes in the activity of antioxidant enzymes were significantly different only for SOD. Based on the results above, pretreatment of carnosine and exercise was found to have a positive effect on protection against oxidative damages and excitatory toxicity which is produced in large amounts in epileptic seizures. This study reported that especially the mixed treatment of regular aerobic exercises and carnosine administration reduced the level of seizure activities and mortality by reducing the protein level of caspase-3, 8 as well as increasing antioxidant enzyme activity.

Helicobacter pylori 제균치료에서 Levofloxacin 병합요법의 효과

이지현 ( Ji Hyun Lee ),홍성표 ( Sung Pyo Hong ),권창일 ( Chang Il Kwon ),편래현 ( Lea Hyun Phyun ),이병석 ( Byoung Sok Lee ),송한얼 ( Han Ul Song ),고광현 ( Kwang Hyun Ko ),황성규 ( Seong Gyu Hwang ),박필원 ( Pil Won Park ),임규성 대한소화기학회 2006 대한소화기학회지 Vol.48 No.1

목적: 현재 사용하는 Helicobacter pylori (H. pylori) 1차 제균 요법은 치료실패가 15-20%이며, 주로 항생제 내성과 연관된다. 이번 연구에서는 H. pylori 제균치료에서 기존 1, 2차 제균요법과 levofloxacin을 포함한 병합요법의 효과를 비교하고자 하였다. 대상 및 방법: 2004년 12월부터 2005년 9월까지 H. pylori 양성 진단을 받고 제균 치료를 받은 267명의 환자들을 대상으로 무작위 배정하여, 141명에서 levofloxacin 포함 병합요법을, 126명에서 기존 PPI 삼제요법을 시행하였다. Levofloxacin 병합요법은 levofloxacin 200㎎ bid, amoxicillin 1.0 g bid, rabeprazole 20㎎ bid를 7일간 투여하였고(LAP), PPI 삼제요법은 clarithromycin 500㎎ bid, amoxicillin 1.0g bid, rabeprazole 20㎎ bid를 7일간 투여하였다 (CAP). 이들 중 1차 제균 치료에 실패한 환자들은 2차 치료로 levofloxacin 병합요법 또는 사제요법을 시행 받았다. 사제요법은 metronidazole 500㎎ bid, tetracycline 1.0g bid, rabeprazole 20㎎ bid, bismuth subcitrate 240㎎ bid를 7일간 투여하였고(MTPB), levofloxacin 병합요법은 1차 치료로 CAP 삼제요법을 시행 받았던 환자들에서는 LAP 삼제요법을, 1차 치료로 LAP 삼제요법을 시행 받았던 환자들에서는 levofloxacin 200㎎ bid, clarithromycin 500㎎ bid, rabeprazole 20㎎ bid를 7일간 투여하였다(LCP). 제균치료가 끝나고 최소 4주 이상 지난 후 요소호기검사로 제균 여부를 확인하였다. 결과: 양 군에서 성별, 연령, 진단, 흡연, 음주 등의 차이는 보이지 않았다. LAP군과 CAP군의 제균율은 per protocol 분석에서 69.8%와 74.0%로 통계적인 차이를 보이 지 않았고, 2차 제균치료의 제균율은 LAP군과 MTPB군에서 각각 62.5%와 40.0%로 LAP군의 제균율이 높게 나타났으나 통계적인 차이는 없었다(p=0.52, p=0.34). 치료 중 약물부작용에 의한 탈락은 양 군 모두에서 없었고, 부작용도 LAP군에서 1.4%, CAP군에서 4.0%로 차이를 보이지 않았다. 성별, 음주, 흡연 여부는 제균율에 영향을 미치지 않았고, 기저 질환에 따른 제균율의 차이도 없었다. 결론: Levofloxacin 포함 병합요법은 기존의 H. pylori 1차 제균요법과 제균율에서 유사하며, 부작용과 환자 유순도에서도 차이가 없었다. 따라서 levofloxacin 포함 병합요법은 H. pylori 1차 제균치료에 있어 효과적이며, 기존의 제균치료에 실패한 환자에서 구제요법으로서의 가능성이 있어 추가 연구가 필요하다. Background/Aims: The failure rates of first and second line therapies of Helicobacter pylori (H. pylori) eradication range from 15 to 20%. This study was aimed to evaluate the efficacy and safety of levofloxacin based triple therapy compared with standard triple or quadruple therapy for H. pylori eradication in Korea. Methods: We enrolled two hundred and sixty seven patients with presence of H. pylori infection. One hundred and forty-one patients were treated with levofloxacin based triple therapy (LAP; levofloxacin, amoxicillin, proton pump inhibitor; PPI), and 126 patients were treated with standard triple therapy (CAP; clarithromycin, amoxicillin, PPI). We retreated the patients who had failed in H. pylori eradication with standard quadruple second-line therapy (MTPB; metronidazole, tetracycline, PPI, bismuth subcitrate) or levofloxacin based therapy (LAP or LCP; levofloxacin, clarithromycin, PPI). Results: In first line therapy of H. pylori eradication, the eradication rates of levofloxacin based triple therapy and standard triple therapy were 69.8% and 74.0% respectively (p=0.52). In second-line therapy, the eradication rate of levofloxacin based triple therapy and standard quadruple therapy were 62.5% and 40.0% respectively (p=0.34). Conclusions: Levofloxacin based triple therapy is effective as standard regimen to eradicate H. pylori infection and is useful for an alternative rescue therapy as well. (Korean J Gastroenterol 2006;48:19-24)

Wells` syndrome associated with henna tattooing

( Hyun Kyu Kim ),( In Kwon Yeo ),( Dong Ha Kim ),( Kui Young Park ),( Kap Sok Li ),( Beom Joon Kim ),( Seong Jun Seo ),( Myeung Nam Kim ),( Chang Kwun Hong ),( Kye Yong Song ) 대한피부과학회 2012 대한피부과학회 학술발표대회집 Vol.64 No.1

Consecutive exposure to Low-dose formaldehyde exacerbates dermatophagoides farinae-induced atopic dermatitis-Like inflammatory immune responses in NC/Nga Mice

( Hyun Kyu Kim ),( Ji Yun Kim ),( Mi Sook Jeong ),( Kui Young Park ),( Kap Sok Li ),( Beom Joon Kim ),( Seong Jun Seo ),( Myeung Nam Kim ),( Chang Kwun Hong ) 대한피부과학회 2011 초록집 Vol.49 No.20