最適化 技法에 의한 南江-安東댐의 洪水調節

李成允,金勝權 외 1인 空軍士官學校 1988 論文集 Vol.25 No.-

The use of an Incremental Dynamic Programming(IDP) for real-time flood control operation is investigated. The optimization model has been applied for the Namgang and Andong hypothetical flood control system in the Nakdong river basin. The objective of the operation is defined to minimize the maximum flow at the confluense of downstreams from the two reservoirs. The results are compared to the direct summation of the flood routing results from individual flood control simulation run. It shows that peak flow at the confluence is reduced markedly by reducing peak outflows from individual reservoirs and by balancing the time of the peak release between the two reservoirs.

Cycling characteristics of PVdF-HFP/Celluose acetate blend polymer membranes for Lithium battery

이성윤,홍진후,김현경 한국고분자학회 2013 한국고분자학회 학술대회 연구논문 초록집 Vol.2013 No.4

Relationship between Maternal Serum C-Reactive Protein, Funisitis and Early-Onset Neonatal Sepsis

이성윤,박교훈,Eun Ha Jeong,오경준,류애리,박경운 대한의학회 2012 Journal of Korean medical science Vol.27 No.6

The aim of this study was to determine whether maternal serum C-reactive protein (CRP) is of value in predicting funisitis and early-onset neonatal sepsis (EONS) in women with preterm labor or preterm premature rupture of membranes (PROM). This retrospective cohort study included 306 consecutive women with preterm labor or preterm PROM who delivered preterm singleton neonates (23-35 weeks gestation) within 72 hr of CRP measurement. The CRP level was measured with a highly sensitive immunoassay. The sensitivity, specificity, positive predictive value, and negative predictive value of an elevated serum CRP level (≥ 8 mg/L) were 74.1%, 67.5%, 32.8%, and 92.4% for funisitis,and 67.7%, 63.3%, 17.2%, and 94.6% for EONS, respectively. Logistic regression analysis demonstrated that elevated levels of serum CRP were significantly associated with funisitis and EONS, even after adjusting gestational age. The maternal serum CRP level obtained up to 72 hr before delivery is an independent predictor of funisitis and EONS in women with preterm labor or preterm PROM. A low serum CRP level (< 8 mg/L) has good negative predictive value in excluding funisitis and EONS, and may therefore be used as a noninvasive adjunct to clinical judgment to identify low-risk patients.

Intra-Amniotic Infection/Inflammation as a Risk Factor for Subsequent Ruptured Membranes after Clinically Indicated Amniocentesis in Preterm Labor

이성윤,박교훈,정은하,오경준,류애리,Ahra Kim 대한의학회 2013 Journal of Korean medical science Vol.28 No.8

The aim of this study was to determine whether intra-amniotic infection/inflammation (IAI)was associated with subsequent ruptured membranes in women with preterm labor and intact membranes who had a clinically indicated amniocentesis. This retrospective cohort study included 237 consecutive women with preterm labor (20-34.6 weeks) who underwent amniocentesis. The clinical and laboratory parameters evaluated included demographic variables, gestational age, C-reactive protein (CRP) and amniotic fluid (AF)white blood cell, interleukin-6 (IL-6) and culture results. IAI was defined as a positive AF culture and/or an elevated AF IL-6 level ( > 2.6 ng/mL). The primary outcome was ruptured membranes in the absence of active labor occurring within 48 hours of amniocentesis. Preterm premature rupture of membranes subsequently developed in 10 (4.2%) women within 48 hr of amniocentesis. Multivariate analysis demonstrated that only IAI was independently associated with the ruptured membranes occurring within 48 hr of amniocentesis. In the predictive model based on variables assessed before amniocentesis,only CRP level was retained. IAI is an independent risk factor for subsequent ruptured membranes after clinically indicated amniocentesis in preterm labor. Prior to amniocentesis,measurement of serum CRP level can provide a risk assessment for the subsequent development of ruptured membranes after the procedure.

종합군수지원(ILS) 실태진단 및 발전방안

이성윤,홍석진 한국국방연구원 2006 국방정책연구 Vol.21 No.4

우리 군은 그동안 종합군수지원(ILS)에 대한 관심 부족과 기반체계 미정립으로 ILS 소요제기의 구체화가 지연되거나 미흡하고, 적시에 적정 예산 편성이 이루어지지 못하여 다시 ILS의 부실로 이어지는 악순환이 반복되고 있다. 이러한 문제점을 개선하기 위해서는 (1) ILS 중장기 종합발전계획 수립 및 단계적 집행, (2) 관련부서간 명확한 책임한계 규명 및 사업별 책임관리체제 구현, (3) ILS 종합관리시스템 구축, (4) 무기체계 운영실적 자료의 체계적 수집, 분석 및 활용체계 구축, (5) 인력 전문화 등이 지속적으로 추진되어야 한다.

장비유지예산 진단 및 발전방향

이성윤 한국국방연구원 2007 국방정책연구 Vol.23 No.2

Appropriate maintenance budgeting and effective execution are the most important factors for the defense readiness but it has been reported that there are a lot of problems in our military maintenance system and each service faces serious lack of maintenance budget. In this study I diagnosed maintenance budgets for the previous ten years and suggested the development strategies to renovate the military maintenance system. The target of developing the maintenance system is to budget reasonably and to execute the maintenance budget effectively. So, I suggested the strategies to construct infra structure and to develop the maintenance policy for these purposes based on the results of diagnosis of the maintenance budget. 본고에서는 과거 10년간의 장비유지예산 집행 실적 분석에 기초하여 최근 제기되고 있는 우려에 대한 근본적인 문제점을 진단해 보고 향후 발전전략을 제시하였다. 장비유지사업에 대한 지난 10년간의 성과는 ‘부족한 재원으로 일정 수준의 전투준비태세를 유지해왔다’로 요약할 수 있으며, 핵심 문제점으로는 ‘초과자산과 재고고갈이 병존하며 예산부족 현상이 발생’하고 있는 것으로 진단하였다. 장비유지분야 발전목표는 적정 장비유지예산 편성 및 집행의 효율성 제고가 될 수 있으므로, 진단결과에 기초하여 장비유지예산 향후 투자 및 정책 방향을 적정 장비유지예산 편성을 위한 기반체계 구축과 장비유지 정책 개선으로 구분하여 제시하였다.

Study on the Relationship and Validity of the Management Evaluation Factors in Public Firms With a Focus on the Port Authorities

이성윤,안기명 한국항해항만학회 2019 한국항해항만학회지 Vol.43 No.6

According to the results of the management evaluation of the nation’s public firms over the past seven years, the rating of the port corporation is generally insufficient. According to the results of the seven-year study 2011-2017, the average debt ratio of the port corporation was 34.5%, two to three times lower than that of the general public company, the operating profit ratio of sales was three times higher, and the value added per person was 1.6-1.9 times better. However, the aggregate score and grade were generally low, with 4.1% of the total number of employees of the general public corporation, 10% of the average total assets, and 1% of the average sales volume. The distributed analysis results and panel return analysis results show that the size significantly impacts the overall score and grade. Additionally, major business standards such as port volume, not controlled by the port corporation, appear to have a decisive influence on the low grade of the port corporation. Thus, it appears that improvement and supplementation of key business indicators of port construction are urgently needed in the management evaluation system, which can be properly controlled.

Enhanced near infrared shielding property of Cs_0.33WO₃ film using multilayer coating

이성윤,김재영,정승용,신교직,최경호,이상국 한국공업화학회 2013 한국공업화학회 연구논문 초록집 Vol.2013 No.-

Modified oxygen transmission model for layer by layer self assembly film

이성윤,민수정,이준영,신교직,최경호,이상국 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Layer by layer self-assembly (LbL-SA) film has been used as a barrier film to disturb the transmission rate of undesired materials that have a higher vapor pressure than an atmospheric pressure. Although several oxygen transmission models have been investigated to correlate the state and contents of inorganic materials such as clay with gas permeability, it is difficult to apply these equations to the LbL-SA film due to the partially condensed clay in each layer. In this study, modified composite-type model was introduced by the sum of each layer. Particularly, it was implied that not only the tortuous pathway but also the pore size and density in the clay layer can be proportioned to the oxygen transmission rate.

우리나라 해운기업의 운전자본관리와 수익성과의 관계에 관한 실증연구

이성윤,Sung-Yhun Lee 한국항해항만학회 2015 한국항해항만학회지 Vol.39 No.3

기업의 운전자본관리는 단기재무전략관리 차원에서 접근이 가능하며, 이는 기업의 유동성 및 수익성 등에 영향관계가 있음이 실증 되고 있다. 따라서 효율적인 운전자본관리는 기업의 수익성을 증대시킬 수 있을 뿐만 아니라, 유동성 또한 개선시킬 수 있게 된다. 해운기업 의 경우 글로벌금융위기와 맞물려 수익성과 유동성에 많은 어려움을 겪었음에도 불구, 운전자본관리와 수익성에 대한 연구는 전무한 상태이 다. 이에 본 연구에서는 2004년 이후 46개 해운기업을 대상으로 운전자본관리와 수익성과의 관계를 규명함으로써 단기재무전략 수립에 유용 한 정보를 제공하고자 하였다. 연구의 결과 기존연구들과 같이 매입채무기간, 재고기간, 현금주기, 영업주기가 해운기업의 수익성 즉, 매출액 총이익률과 매출액영업이익률을 개선할 수 있는 중요한 요인인 것으로 실증되었다. 특히 매입채무신용기간과 영업주기의 증가는 수익성의 증 가를 가져오는 것으로 분석된 반면, 재고기간과 현금주기는 부(-)의 관계를 보여 이들이 줄어들 경우 수익성이 증가하는 것으로 나타났다. 매 출채권기간은 일부 모형에서 유의하였으나, 기존 연구들과는 달리 해운기업의 경우 수익성과의 관계를 설명하기에는 한계가 있는 것으로 나타났다. Many of previous studies suggested that working capital management is an important component of firm’s financial decision and efficient working capital management affects firms‘ profitability and it’s value. Recently, Korean shipping firms have been suffering from financial distress by recession of shipping economy. In this point of view, this study tries to investigate the relationship between working capital management and shipping firm’s profitability, using panel data on 46 Korean shipping firms for the period of 2004-2013. As result of panel regression, it proved that average payment period, inventory turnover, cash conversion cycle and operating cycle are significantly associated with firms profitabilities such as profit margin ratio and operating profit ratio, and the manager of shipping firm can increase firms profitability by more efficient working capital management. There are strong positive relationships between average payment period and operating cycle and firm’s profitability. These results suggest that managers can create firm’s value by increasing average payment period and operating cycle. Otherwise inventory turnover and cash conversion cycle have negative relationships with firm’s profitability. It means that managers can increase firm’s profitability by reducing these variables