Concurrent Relations of Commodity Futures

Namkoong,Hongseok,Kim, Woochang 대한산업공학회 2011 대한산업공학회 추계학술대회논문집 Vol.2011 No.11

Literatures have focused on the relationship between basis, cost of storage and convenience yield, as given by the Theory of Storage. However, the relations among futures contracts should be considered as a whole, upon discussion of futures-spot relationships: futures curve reflects inventory level and the risk premium and thus the dynamics of future spot price. Here the predictive ability of the futures curve over future spot price dynamics is empirically proven. When the futures curve is highly volatile, market participants’ expectation on inventory and risk premium vary. As this discrepancy widen, spot inventory is deemed unstable. Thus, spot price rises for a short time. But then, as inventory restores itself, spot mean reverts, making a sharp market correction. An investment strategy that predicts spot price crashes using the futures curve is devised. Equal weight portfolio of 26 commodities is used. Results corroborate the conjecture; it predicts major market crashes. Result indicates that contemporary relations among futures contracts are crucial in futures-spot relationships. This result expands the view offered by the Theory of Storage by highlighting the importance of relationship among futures contracts.

MoSi2 의 초음파에 관한 기초적 연구

김유철,남궁재관 한국산업안전학회 1994 한국안전학회지 Vol.9 No.1

Ultrasonic for MoSi₂/Y. C. Kim, C. K. Namkoong/MoSi₂ in the silicides has excellence in the oxidation and corrosion resistence. When the solid state bonding sintered-MoSi₂/metal or the thermal sprayed coating by powder-MoSi₂ on the metal are carried out, the defects may be occured at the bonded surface. So, the method for evaluating the existence of the defects by non-destructive inspection is strongly desired. Here, the characteristics of ultrasonic for sintered-MoSi₂ are elucidated and the possibility of the detection of defects using by ultrasonic is investigated.

Contour machining error in NC milling process

Namkoong, Chaikwan,Yellowley, I. 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.6

The comprehensive system analysis for contour milling operation has performed in this study, which combined the each element with proper connectivity into closed loop system, and determined the system response by numerical simulation technique. The obtained simulated results were then compared with the experimental results from the practical points of view, and so forth, the governing equations were formulated into the estimation model, which predicted the total contour machining error within 25% accuracy. Through the procedural evaluation, it could ascertain the characteristics of generation mechanics in circular contour machining error, and the weight of each factor.

Central administration of GLP-1 and GIP decreases feeding in mice

NamKoong, C.,Kim, M.S.,Jang, B.T.,Lee, Y.H.,Cho, Y.M.,Choi, H.J. Academic Press 2017 Biochemical and biophysical research communication Vol. No.

Glucagon-like peptide-1 amide (GLP-1) and gastric inhibitory polypeptide (GIP) are incretin hormones regulating energy metabolism. GLP-1 and GIP combination is suggested as a promising therapeutic strategy for treatment of obesity and diabetes. However, the neuronal mechanisms are not yet investigated. In the present study, we investigated the role of central GLP-1 and GIP in regulation of body weight homeostasis. The effect of GLP-1 with GIP on food intake, body weight, locomotor activity were determined following intracerebroventricular (ICV) administration of GLP-1 and/or GIP in mice. ICV administration of low dose GLP-1 (0.3 nmol) and GIP (1 and 3 nmol) did not change food intake. However, ICV administration of higher doses GLP-1 (1 and 3 nmol) and GIP (6 nmol) significantly decreased food intake and body weight. To investigate the synergic effect of ICV GLP-1 and GIP, subeffective dose GLP-1 (0.3 nmol) and subeffective dose GIP (1 nmol) were chosen for further co-administration study. ICV co-administration of GLP-1 and GIP significantly decreased food intake, body weight and drinking. ICV co-administration of GLP-1 and GIP significantly increased neuronal activation and pro-opiomelanocortin (POMC) expression in hypothalamic arcuate nucleus. The neuronal activation and POMC expression were observed in two distinct neuronal populations. These results provide neuronal mechanisms supporting the development of GLP-1 and GIP combination therapeutics for treatment of obesity and diabetes.

Enhanced Hypothalamic AMP-Activated Protein Kinase Activity Contributes to Hyperphagia in Diabetic Rats

Namkoong, C.,Kim, M. S.,Jang, P. G.,Han, S. M.,Park, H. S.,Koh, E. H.,Lee, W. J.,Kim, J. Y.,Park, I. S.,Park, J. Y.,Lee, K. U. American Diabetes Association 2005 Diabetes Vol.54 No.1

<P>AMP-activated protein kinase (AMPK) acts as a cellular energy sensor, being activated during states of low energy charge. Hypothalamic AMPK activity is altered by hormonal and metabolic signals and mediates the feeding response. To determine the effect of diabetes on hypothalamic AMPK activity, we assayed this activity in streptozotocin (STZ)-induced diabetic rats. Compared with control rats, STZ-induced diabetic rats had significant hyperphagia and weight loss. Hypothalamic AMPK phosphorylation and alpha2-AMPK activity were higher and acetyl-CoA carboxylase activity was lower in diabetic rats than in control rats. Chronic insulin treatment or suppression of hypothalamic AMPK activity completely prevented diabetes-induced changes in food intake as well as in hypothalamic AMPK activity and mRNA expression of neuropeptide Y and proopiomelanocortin. Plasma leptin and insulin levels were profoundly decreased in diabetic rats. Intracerebroventricular administration of leptin and insulin reduced hyperphagia and the enhanced hypothalamic AMPK activity in diabetic rats. These data suggest that leptin and insulin deficiencies in diabetes lead to increased hypothalamic AMPK activity, which contributes to the development of diabetic hyperphagia.</P>

Politics over National Health Insurance System in the United States : Lessons from the Past History

Namkoong Keun(남궁근),Kim, Yeoung-ki(김영기) 경상대학교 사회과학연구원(사회과학연구) 1988 사회과학연구 Vol.6 No.-

A Study on Circular Contour Machining Error

Namkoong, Chaikwan 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.5

The comprehensive system analysis for contour milling operation and its error has performed in this study. The obtained experimental results were from the practical points of view. In down-milling operation the contour error curve illustrates bigger thean actual workpiece radius. The contour error increased when the cutter loads increased. Through the procedural evaluation, it could ascertain the characteristics of generation mechanics in circular contour machining error, and the weight of each factors.

Genetic Variations of Human Plasma α1B - Glycoprotein(α1B)by Two - Dimensional Electrophoresis or Immunoblotting

NamKoong, Yong,Lee, Chung Choo,Hong, Seung Ho,Oh, Moon You 한국유전학회 1990 Genes & Genomics Vol.12 No.4

Genetic variations of human plasma α₁B-glycoprotein (α₁B) was observed using two-dimensional agarose gel electrophoresis (pH 5.4) - horizontal polyacrylamide gel electrophoresis (PAGE), pH 9.0 or one-dimensional PAGE (pH 9.0) followed Western blotting with specific antiserum to α₁B as alternative method. Among the 612 unrelated individuals living in Seoul (205 individuals), Kangreung (200 individuals) and Cheju (207 individuals) of Korea, four different α₁B phenotypes (1-1, 1-2, 2-2 and 1-3) were identified. Also, to conform whether each types are the same protein, peptide mapping of these proteins was performed. The frequencies of A1B^*1, A1B^*2 and A1B^*3 alleles were calculated to be 0.8897, 0.1021 and 0.0082, respectively. Mongoloid populations showed a higher degree (polymorphism information content) of α₁B variations than Caucasian populations that have been studied except Swedish Lapps population.

Chemically, spatially, and temporally resolved 2D mapping study for the role of grain interiors and grain boundaries of organic-inorganic lead halide perovskites

Namkoong, Gon,Jeong, Hyeon Jun,Mamun, Abdullah,Byun, Hyeryung,Demuth, Derek,Jeong, Mun Seok North-Holland 2016 Solar Energy Materials and Solar Cells Vol. No.

<P><B>Abstract</B></P> <P>Grain interiors (GIs) and grain boundaries (GBs) of perovskites have been investigated using chemically, spatially, and temporally resolved measurements. Two dimensional (2D) chemical mapping measurements revealed the GBs consisted of the non-stoichiometric PbI<SUB>x</SUB> or CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>x</SUB>, that were characterized by an absence of chloride, an enriched oxygen concentration, and a high density of iodide vacancies. In addition, steady-state 2D photoluminescence showed the bandgap broadening at the GBs while 2D lifetime mapping measurement suggested that the GBs indeed contained deep defect centers. However, it is found that defective GBs in perovskite materials do not act as high recombination sites for photogenerated charge carriers due to the bandgap broadening of non-stoichiometric PbI<SUB>x</SUB> or CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>x</SUB> perovskites at the GB that forms the potential barriers for photo-generated charge carriers toward the GBs. As a consequence, the photo-generated charge carriers adjacent to the GBs will be easily repelled by the GBs, resulting in a greater reduction of the recombination of photogenerated charge carriers. This is one possible reason for the high performance of CH<SUB>3</SUB>HN<SUB>3</SUB>PbI<SUB>3-x</SUB>Cl<SUB>x</SUB> based solar cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Grain interiors and grain boundaries of perovskites have been investigated. </LI> <LI> Bandgap broadening at the GBs was formed due to PbI<SUB>x</SUB> or CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>x</SUB>. </LI> <LI> GBs were characterized by no chloride, enriched oxygen, and iodide vacancies. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Two-dimensional photoluminescence and time resolved lifetime contrasting the grain interiors and grain boundaries.</P> <P>[DISPLAY OMISSION]</P>

The integral membrane protein ITM2A, a transcriptional target of PKA-CREB, regulates autophagic flux via interaction with the vacuolar ATPase

Namkoong, Sim,Lee, Kang Il,Lee, Jin I,Park, Rackhyun,Lee, Eun-Ju,Jang, Ik-Soon,Park, Junsoo TaylorFrancis 2015 AUTOPHAGY Vol.11 No.5

<P>The PKA-CREB signaling pathway is involved in many cellular processes including autophagy. Recent studies demonstrated that PKA-CREB inhibits autophagy in yeast; however, the role of PKA-CREB signaling in mammalian cell autophagy has not been fully characterized. Here, we report that the integral membrane protein ITM2A expression is positively regulated by PKA-CREB signaling and ITM2A expression interferes with autophagic flux by interacting with vacuolar ATPase (v-ATPase). The <I>ITM2A</I> promoter contains a CRE element, and mutation at the CRE consensus site decreases the promoter activity. Forskolin treatment and PKA expression activate the <I>ITM2A</I> promoter confirming that ITM2A expression is dependent on the PKA-CREB pathway. ITM2A expression results in the accumulation of autophagosomes and interferes with autolysosome formation by blocking autophagic flux. We demonstrated that ITM2A physically interacts with v-ATPase and inhibits lysosomal function. These results support the notion that PKA-CREB signaling pathway regulates ITM2A expression, which negatively regulates autophagic flux by interfering with the function of v-ATPase.</P>