미국의 지역별 생산 유・가스전 가치평가의 특성요소 분석

신승헌,임종세,박희원 한국자원공학회 2012 한국자원공학회지 Vol.49 No.3

The value of oil and gas producing asset can be calculated by a discounted cash flow analysis and transaction metric analysis from historical transaction data. This paper presents an analysis on U.S. producing assets to characterize various factors affecting the value of oil and gas assets through the analysis of ten transaction data in Permian basin, Gulf of Mexico, and Texas & Oklahoma, U.S. The results of cash flow analysis on target projects show that transaction metrics can be affected by oil/gas ratio in reserves, well life related to well decline characteristics and PDP portion in proved reserves. The value of oil and gas asset increases with higher oil portion in reserves, higher initial production characteristics in case of equivalent reserves, longer life characteristics in case of equivalent current production rate. Also, offshore assets have higher portion of fixed operating cost and plug and abandon cost in total cash flow than onshore assets. 생산 유・가스전의 가치는 할인현금흐름분석법과 과거 유・가스전 거래사례에서 얻어진 매장량, 일생산량, 에이커 등의 거래 단가 등을 비교하여 결정된다. 이 연구에서는 미국의 대표적인 유전거래 지역인 퍼미안 분지, 멕시코만 해상, 텍사스-오클라호마 육상 3곳의 10개 유・가스전 자료를 이용하여 생산 유・가스전 거래단가에 영향을 미치는 특성요소들을 분석하였다. 각 유・가스전의 자료와 현금흐름분석 결과 지역적 유・가스전의특성인 원유/가스 매장량 비율, 생산감쇄율과 관련된 생산가채년수, 확인매장량 중 확인개발생산매장량의 비율 등에 따라 거래단가가 영향을 받음을 알 수 있었다. 유가가 강세인 현재 매장량 중 원유 비율이 높을수록, 동일한 매장량의 유・가스전의 경우 멕시코만과 같이 회수가 빠른 유・가스전이, 동일한 양으로 생산 중인 유・가스전의 경우 퍼미안과 같이 가채년수가 긴 유・가스전이 높은 가치를 지닌다. 또한, 현금흐름을 통한 운영단가 분석 결과 해상의 경우 육상에 비해 고정 운영비 및 폐공 비용이 전체 현금흐름에서 차지하는 비중이 높음을 알 수 있었다.

Cooperative effect of Alternaria and rhinovirus on the activation of nasal polyp epithelial cells

신승헌,예미경,전병규,장용주 대한비과학회 2012 Journal of rhinology Vol.19 No.2

Background and Objectives : The nasal epithelium is the first barrier encountered by airborne allergens and is an active participant in airway inflammation. The aim of this study was to determine the activation mechanism of nasal epithelial cells with Alternaria and the effect of rhinovirus on the Alternaria induced activation of nasal epithelial cells. Materials and methods : Cultured epithelial cells were stimulated by Alternaria with or without rhinovirus-16 (RV-16) infection. Release of interleukin (IL)-6, IL-8, and granulocyte macrophage colony-stimulating factor (GM-CSF) into culture supernatants were measured to determine the activation of epithelial cells. Nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) of the epithelial cells were analyzed using western blot analysis. Intracellular NF-kB and AP-1 activity were evaluated by enzyme-linked immunosorbent assay. To determine the epithelial cell activation mechanism, cytokine production was inhibited with NF-kB, AP-1, and mitogen activated protein kinase (MAPK) inhibitors. Results : Exposure of epithelial cells to Alternaria enhanced the production of cytokines. Intracellular NF-kB expression and activity were significantly increased by Alternaria, but not by RV-16. AP-1 expression and activity were not influenced by Alternaria. Increased IL-6 production was significantly inhibited by transcription factor inhibitors. However, IL-8 and GM-CSF production were not inhibited by these transcription factor inhibitors. Conclusions : Our in-vitro results demonstrate that Alternaria activates nasal polyp epithelial cells via NF-kB pathway and that NF-kB, AP-1, and MAPK are involved in the production of IL-6.

당질스테로이드를 이용한 진균에 의한 비강상피세포의 활성화 억제

신승헌 대한비과학회 2006 Journal of rhinology Vol.13 No.1

Background and Objectives:Airway epithelial cells contribute to the pathogenesis of air disease by their interaction with inhalant pathogenic extracts. Airborne fungi interact with nasal epithelial cell and enhance the production of inflammatory cytokines. Glucocorticosteroids (GCs) have been used therapeutically for nasal polyps and allergic disease with potent anti-inflammatory effects. The purpose of this study was to investigate the inhibitory effect of GCs on fungi induced nasal epithelial cell activation. Materials and Methods:The epithelial cells of nasal polyps were obtained from patients and stimulated with Alternaria. To evaluate the anti-inflammatory effects of GCs, Alternaria was pretreated with GCs (triamcinolone, dexamethasone, and budesonide) and cultured with epithelial cells. Interleukin-8 (IL-8) and granulocyte-macrophage colony stimulating factor (GM-CSF) were measured to determine the activation of epithelial cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) test for protease-activated receptors (PARs) mRNA expression in nasal epithelial cells were performed. Results:Alternaria enhanced the production of IL-8 and GM-CSF from nasal epithelial cells. GCs inhibited the activation of nasal epithelial cells, but the PAR2 and PAR3 mRNA expression were not suppressed by GCs. Conclusion:These data suggest that GCs inhibit the production of chemical mediators by Alternaria, but anti-inflammatory effect of GCs are not associated with PARs. 당질스테로이드·Alternaria·비강상피세포·Protease-activated receptor.

비용성 만성부비동염의 발병에 있어 진균과 세균 초항원의 역할

신승헌 대한비과학회 2008 Journal of rhinology Vol.15 No.2

Chronic rhinosinusitis (CRS) is an inflammatory disorder with numerous predisposing factors, including genetics, anatomic anomalies, bacteria, and fungus. CRS with nasal polyps can be distinguished by an eosinophilic type inflammation with a high concentration of IgE. Recent studies have implicated exposure to superantigens derived from Staphylococcus aureus and Alternaria as possible causes for the pahophysiology of nasal polyps. Superantigens are microbial toxins that bind to human leukocyte antigen class II histocompatibility molecules on antigen-presenting cells and T cell receptors on T cells simultaneously, bypassing classical antigen specificity. T lymphocyte sensitization to superantigen with production of the T-helper 2 cytokines has been proposed as a key step in the initiation of nasal polyps. This review summarize the current evidence for an active role of fungal and bacterial superantigens in CRS with nasal polyps. However, therapeutic approaches are so far limited and empirical, and need further improvement. Chronic rhinosinusitis (CRS) is an inflammatory disorder with numerous predisposing factors, including genetics, anatomic anomalies, bacteria, and fungus. CRS with nasal polyps can be distinguished by an eosinophilic type inflammation with a high concentration of IgE. Recent studies have implicated exposure to superantigens derived from Staphylococcus aureus and Alternaria as possible causes for the pahophysiology of nasal polyps. Superantigens are microbial toxins that bind to human leukocyte antigen class II histocompatibility molecules on antigen-presenting cells and T cell receptors on T cells simultaneously, bypassing classical antigen specificity. T lymphocyte sensitization to superantigen with production of the T-helper 2 cytokines has been proposed as a key step in the initiation of nasal polyps. This review summarize the current evidence for an active role of fungal and bacterial superantigens in CRS with nasal polyps. However, therapeutic approaches are so far limited and empirical, and need further improvement.

時定數(Time Delay)가 큰 系에 對한 人間의 制御 Pattern

신승헌 啓明大學校 産業技術硏究所 1981 産業技術硏究所 論文報告集 Vol.3 No.-

Large individual differences in control pattern are observed when we control a control object with long time delay such as large tanker. A human control model was combined with a control object simulator to analyze differences. This human control model was devised to feed-back the information of location and direction which are essential to control a ship. It was possible to choose and change the appropriate coefficient relation to deviation between the current location of the ship and the value of the goal trajectory, and the feed-back gain of direction. And it was possible to represent the control pattern of long time delay system by individual. Followings are the results of the experiments with the human control model and operators. 1) The paper balance between the information of direction and direction is required. 2) The following tendency was proved when an operator turned more to be an expert ; its influence on the operator handle control became constant if the deviation becomes bigger. 3) When the ship`s speed was retained constant, the following tendency was observed ; the longer the time delay of the handle is made, the later the control performance became of operator paid attention to direction rather than deviation between current location and goal trajectory.

Surface Polarity Dependent Photo-response of GaN MSM Ultraviolet (UV) Sensors

신승헌,김동석,우종창,이헌복,함성호,김도균 한국전기전자재료학회 2024 Transactions on Electrical and Electronic Material Vol.25 No.4

In this work, we fabricate and characterize ultraviolet (UV) sensors on Ga-polar and N-polar GaN structures. Heterostructure of the Ga-polar GaN structure is grown on a sapphire substrate by using metal organic chemical vapor deposition (MOCVD). Moreover, the N-polar GaN structure is prepared by using epitaxial lateral overgrowth (ELOG) and separating from the sapphire by laser lift-off (LLO). The leakage current of the Ga-polar GaN structure is six orders lower compared to that of N-polar GaN before annealing thanks to the lower dislocation density of the Ga-polar GaN structure. The UVvisible extinction ratio is almost 10 2 in the N-polar GaN structure, and 10 4 in the Ga-polar GaN structure. In addition, the UV-visible extinction ratio of the Ga-polar GaN structure is greatly improved after thermal treatments at 500 oC and 800 oC. It exhibits a UV-A band-pass-like feature in the UV-visible extinction ratio of the Ga-polar GaN structure.

진균의 단핵구 유래 수상세포의 활성화와 Th 면역반응에 미치는 영향

신승헌,예미경,한바다 대한비과학회 2010 Journal of rhinology Vol.17 No.2

Background and Objectives:The mucosal immune response depends on the surveillance network established by dendritic cells (DC) localized within the respiratory epithelium. Fungi have been increasingly recognized as important pathogens in respiratory diseases. We hypothesized that DCs play a central role in the immune response against airborne fungi. Materials and Methods:Monocyte-derived DCs were developed by incubating monocytes with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor. DCs were stimulated with Alternaria alternata and Aspergillus nigra for 24 hours and then co-cultured with CD4-positive lymphocytes for 6 days. Levels of IL-6 and tumor necrosis factor-α (TNF-α) were measured to determine activation of the DCs, and levels of TNF-α, IL-5, and interferon-γ (INF-γ) were measured to determine Th polarization. DC migration was induced with conditioned media from nasal polyp epithelial cells stimulated with fungi. Results:Alternaria and Aspergillus activated DCs with enhanced production of cytokines. When activated DCs were co-cultured with CD4-positive lymphocytes, Th2 cytokine and IL-5 production was significantly increased by Alternaria. DC migration was significantly increased by conditioned media from cells that were activated with Alternaria. Conclusion:Airborne fungi induced different immune responses depending on the fungi. Alternaria strongly induced DC migration and a Th2 immune response.

Effects of Fungi and Eosinophils on Mucin Gene Expression in Rhinovirus-Infected Nasal Epithelial Cells

신승헌,예미경,김정규 대한천식알레르기학회 2014 Allergy, Asthma & Immunology Research Vol.6 No.2

Purpose: Fungi, rhinoviruses (RVs), and eosinophils are associated with upper respiratory diseases. We evaluated the effects of fungal stimulationand eosinophil co-culture on the expression of mucin genes in RV-infected nasal polyp epithelial cells. Methods: Nasal polyp epithelial cells wereobtained from chronic rhinosinusitis patients. Cultured epithelial cells were stimulated with Alternaria and Aspergillus with or without RV-16 infection. The epithelial cells were co-cultured with eosinophils for 16 hours. MUC4, MUC5AC, MUC5B, and MUC8 mRNA expressions in the epithelial cellswere quantified using real-time RT-PCR. To determine the underlying mechanism, nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and mitogenactivatedprotein kinase (MAPK) inhibitors were used to inhibit mucin gene expression. Results: Fungi and RV-16 induced mucin gene expressionin nasal polyp epithelial cells. However, there was no synergistic increase in mucin gene expression, with the exception of MUC4 mRNA expressionstimulated by 25 μg/mL Aspergillus. When RV-16-infected epithelial cells were stimulated with fungi and then co-cultured with eosinophils, MUC4,MUC5B, and MUC8 mRNA expressions increased. Mucin gene expression was inhibited by NF-κB inhibitors. Conclusions: RV-16, airborne fungi,and eosinophils may exacerbate the inflammatory process in nasal mucosal diseases by enhancing mucin gene expression.

옴나리스Ⓡ에 의한 비용상피세포 염증반응 및 점액유전자 발현 억제

신승헌,강승현,진효승,김이혁,예미경 대한이비인후과학회 2014 대한이비인후과학회지 두경부외과학 Vol.57 No.9

Background and Objectives Glucocorticoids are a potent anti-inflammatory agent. The au-thors conducted this study to investigate the effect of Omnaris® on suppression of inflammation induction and mucin gene expression in nasal polyp epithelial cells. Subjects and Method Primary nasal polyp epithelial cells were stimulated by 5 ug/mL of streptococcal enterotoxin B (SEB) and lipopolysaccharide (LPS). To determine the effects of Omnaris®, cells were pretreated with 200, 100, 10, 1 ng/mL of Omnaris®. The anti-inflammatory effect of epithelial cells were confirmed by measuring interleukin (IL)-6, IL-8, and granulocyte-macrophage colony stimulating factor (GM-CSF), and mucin gene expressions were determined by real time PCR for MUC4, MUC5AC, MUC5B, MUC8. Results SEB and LPS enhanced the production of IL-6, IL-8, and GM-CSF from nasal polyp epithelial cells. The increased cytokine levels were significantly suppressed by Omnaris® at 100 and 10 ng/mL. The expressions of MUC4, MUC5AC, MUC5B, MUC8 mRNA, and MUC4 mRNA were increased by SEB and LPS, respectively. The increased expression of these mucin genes were significantly suppressed by 100, 10, and 1 ng/mL of Omnaris®. Conclusion Omnaris® significantly suppressed the production of chemical mediators and mucin gene expression, which indicated that Omnaris® is effective in improving and treating inflammatory diseases in the nasal cavity. Korean J Otorhinolaryngol-Head Neck Surg 2014;57(9):603-9

호산구성 만성비부비동염

신승헌 대한이비인후과학회 2013 대한이비인후과학회지 두경부외과학 Vol.56 No.9

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the nasal and paranasal sinus mucosa. Generally CRS can classify depend on the presence of polyps or eosinophilic infiltration. Eosinophils have immune-modulatory effects on the inflammatory response of CRS and eosinophilia has been noted to be a marker for more extensive disease. Eosinophilic CRS (ECRS) is a clinical entity of chronic inflammation accompanied by numerous infiltrations of eosinophils in sinonasal tissues. The purpose of this review is to define and characterize the potential subcategories of ECRS and to discuss pathophysiology for targeted treatment modalities. Although it is difficult to differentiate one form of ECRS from another, genetic and molecular study will lead to unreveal the immunologic mechanism and pathogenesis of ECRS.