• KDI Journal of Economic Policy
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• v.13 no.2
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• pp.3-19
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• 1991

This paper attempts to identify key determinants of long run movements of real M2 by using the Johansen procedure for estimating and testing cointegration relations. It turns out that the real M2 equation has been stable over the long run despite rapid changes in financial structure since 1975. Moreover, the real M2 equation can be reduced to a velocity equation with the opportunity cost variable, expected inflation less the weighted average rate paid on M2 deposits, being the key determinant. However, it does not work to use a market interest rate such as the yield on corporate bonds in place of expected inflation for calculation of the opportunity cost. In the U.S., a market interest rate can be used, but not in Korea. Presumably, two somewhat different reasonings can be used to explain this result. One is that the yield on corporate bonds may not adequately reflect the inflationary expectations due to regulations on movements in interest rates. The other is that M2 deposits are not readily substitutable with such assets as corporate bonds because of market segmentations, regulations, and so on. From the policymaker's point of view, this implies that the inflation rate is an important indicator of a policy response. On the other hand, policymakers do not regard movements of the yield on corporate bonds as an important policy indicator. Altogether, the role of interest rates has been quite limited in Korea because of incomplete interest rate liberalization, an underdeveloped financial system, implementation procedures of policy measures, and so on. The result that M2 velocity has a positive cointegration relation with expected inflation minus the average rate on M2 implies that frequent adjustments of the regulated rates on M2 will be necessary as market conditions change. As the expected inflation gets higher, M2 velocity will eventually increase, given that the rates on M2 do not change. This will cause higher inflation. If interest rates are liberalized, then increases in market interest rates will result in lagged increases in deposits rates on M2. However, in Korea a substantial portion of deposit rates are regulated and will not change without the authority's initiatives. A tight monetary policy will cause increases in a few market interest rates. But the market mechanism, upward pressure for interest rate adjustments, never reaches regulated deposit rates. Hence the overall effects of tight monetary policy diminish considerably, only causing distortions in the flow of funds. Therefore, frequent adjustments of deposit rates are necessary as market conditions such as inflationary expectations change. Then it becomes important for the policymaker to actively engage in adjusting regulated deposit rates, because the financial sector in Korea is not fully developed.

• Journal of the Korean earth science society
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• v.41 no.1
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• pp.19-30
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• 2020

To understand the impact of typhoons on Gamji gravel beach Taejongdae in Busan, we carried out beach profiling using a VRS-GPS system and a Drone photogrammetry for the typhoons 'Kong-rey' invaded in October 2018 and 'Danas' in July 2019. In addition, grain sizes are analyzed to investigate the overall distribution pattern of gravels on the beach, and the beach topography is surveyed periodically to confirm the recovery rate of the beach. Grain-size analysis reveals that mean gravel sizes, in general, become finer from -6.2Φ to -5.4Φ towards the east in the seashore line direction. Variation in mean sizes is obviously observed in the cross-shore direction. Gravels in the swash zone are relatively fine about -4.5Φ in size and equant in shape, whereas the coarse and oblate gravels ranged from -5Φ to -6Φ are found in the berm. Gamji gravel beach particularly has two lines of berms: a lower berm situated facing beach and an upper berm about 10 m landward. After the typhoon Kong-rey passed by, about 1.4 m of severe erosion in upper berm occurred, and the berm eventually disappeared. On the backshore of the upper berm about 50 cm of erosion took place so that the elevation became lower. However, tangible erosion was not observed in the lower berm. When typhoon Danas hit, rated as mild storm, both upper and lower berm were eroded out. However, about 50 cm of deposition occurred only in the backshore. Only three days later, the new lower berm was formed, meaning that sedimentation rate must be high. This result indicates that Gamji gravel beach is recovered very fast from erosion caused by the typhoons when it is under the fair-weather condition even though beach morphology changes dramatically in a short period of time. Gravel beach is estimated to be or evaluated very resilient to typhoon erosion.

• Korean Journal of Biological Psychiatry
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• v.15 no.4
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• pp.275-287
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• 2008

Depression and coronary artery disease are both highly prevalent diseases. Many previous studies suggest that depression is a common comorbid condition in patients with coronary artery disease and has a significant negative impact on the onset, course, and prognosis of coronary artery disease. However, the exact mechanisms that underlie the association between these two diseases remain unclear. Pathophysiologic mechanisms that may explain the effect of depression on coronary artery disease include hypercoagulability, hypothalamus-pituitary-adrenal axis and autonomic nervous system dysregulation, altered inflammatory response. On the contrary, pathophysiologic mechanisms in coronary artery disease that affect depression are less well known. It is also suggested that both diseases may share a common genetic vulnerability. The authors reviewed the literature on the pathophysiologic relationships of depression and coronary heart disease.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.266-274
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• 2010

This study aim to investigate fundamentally the growth and physiological responses of tomato plants in responses to two different levels of water deficit, a weak drought stress (-25 kPa) and a severe drought stress (-100 kPa) in soil. The two levels of water deficit were maintained using a micro-irrigation system consisted of soil sensors for the real-time monitoring of soil water content and irrigation modules in a greenhouse experiment. Soil water contents were fluctuated throughout the 30 days treatment period but differed between the two treatments with the average -47 kPa in -25 kPa set treatment and the -119 kPa in -100 kPa set treatment. There were significant differences in plant height between the two different soil water statuses in plant height without differences of the number of nodes. The plants grown in the severe water-deficit treatment had greater accumulation of biomass than the plants in the weak water-deficit treatment. The severe water-deficit treatment (-119 kPa) also induced greater leaf area and leaf dry weight of the plants than the weak water-deficit treatment did, even though there was no difference in leaf area per unit dry weight. These results of growth parameters tested in this study indicate that the severe drought could cause an adaptation of tomato plants to the drought stress with the enhancement of biomass and leaf expansion without changes of leaf thickness. Greater relative water content of leaves and lower osmotic potential of sap expressed from turgid leaves were recorded in the severe water deficit treatment than in the weak water deficit treatment. This finding also postulated physiological adaptation to be better water status under drought stress. The drought imposition affected significantly on photosynthesis, water use efficiency and stomatal conductance of tomato plants. The severe water-deficit treatment increased PSII activities and water use efficiency, but decreased stomatal conductance than the weak water-deficit treatment. However, there were no differences between the two treatments in total photosynthetic capacity. Finally, there were no differences in the number and biomass of fruits. These results suggested that tomato plants have an ability to make adaptation to water deficit conditions through changes in leaf morphology, osmotic potentials, and water use efficiency as well as PSII activity. These adaptation responses should be considered in the screening of drought tolerance of tomato plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.3
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• pp.229-238
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• 2018

The purpose of this study was to evaluate the effects of nitrogen fertilization amount and timing of application on protein content, dough properties, change in protein fraction, and bread loaf volume for Korean wheat cultivars, Baekkang, Joongmo2008, and Saekeumkang, for bread with a superior gluten composition during the grain filling stage. Protein content increased with an increase in the amount of N and timing of application. The SDS segmentation volume (SDSS) increased with an increase in N, but there was no effect of the timing of N application on SDSS. An increase in N amount and timing of application caused a difference in dough properties, such as water absorption, mixing time, and tolerance, among the cultivars. Soluble and insoluble polymeric and monomeric protein contents increased with an increase in N amount and timing of application the three Korean wheat cultivars. The effects of N amount and application timing on bread loaf volume (BLV) varied among the cultivars. The BLV of Saekeumkang increased regardless of the N amount and timing of application, but that of Baekkang and Joongmo2008 cultivars was reduced. However, there was a positive correlation between protein content with the addition of N fertilization and BLV. In addition, SDSS, mixing time, and protein fractions were positively correlated with BLV. Since the response of fertilizer conditions was different for each wheat cultivar, it is necessary to build a suitable fertilizing system for each of them. Additionally, since the environment is changing, such as abnormal climate during the maturing period, research is needed to establish appropriate fertilizer conditions for varieties of bread wheat.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.8-9
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• 2017

Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

• Toxicological Research
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• v.24 no.3
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• pp.175-182
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• 2008

DNA-dependent protein kinase(DNA-PK) is involved in joining DNA double-strand breaks induced by ionizing radiation or V(D)J recombination and is activated by DNA ends and composed of a DNA binding subunit, Ku, and a catalytic subunit, DNA-PKcs. It has been suggested that DNA-PK might be $2^{nd}$ upstream kinase for protein kinase B(PKB). In this report, we showed that Ser473 phosphorylation in the hydrophobic-motif of PKB is blocked in DNA-PK knockout mouse embryonic fibroblast cells(MEFs) following insulin stimulation, while there is no effect on Ser473 phosphorylation in DNA-PK wild type MEF cells. The observation is further confirmed in human glioblastoma cells expressing a mutant form of DNA-PK(M059J) and a wild-type of DNA-PK(M059K), indicating that DNA-PK is indeed important for PKB activation. Furthermore, the treatment of cells with doxorubicin, DNA-damage inducing agent, leads to PKB phosphorylation on Ser473 in control MEF cells while there is no response in DNA-PK knockout MEF cells. Together, these results proposed that DNA-PK has a potential role in insulin signaling as well as DNA-repair signaling pathway.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.360-373
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• 2017

The BTO-a projects is the types, which has a demand risk among the type of PPP projects in Korea. When demand risk is realized, private investor encounters financial difficulties due to lower revenue than its expectation and the government may also have a problem in stable infrastructure operation. In this regards, the government has applied various risk sharing policies in response to demand risk. However, the amount of government's risk sharing is the government's contingent liabilities as a result of demand uncertainty, and it fails to be quantified by the conventional NPV method of expressing in the text of the concession agreement. The purpose of this study is to estimate the value of investment risk sharing by the government considering the demand risk in the profit sharing system (BTO-a) introduced in 2015 as one of the demand risk sharing policy. The investment risk sharing will take the form of options in finance. Private investors have the right to claim subsidies from the government when their revenue declines, while the government has the obligation to pay subsidies under certain conditions. In this study, we have established a methodology for estimating the value of investment risk sharing by using the Black - Scholes option pricing model and examined the appropriateness of the results through case studies. As a result of the analysis, the value of investment risk sharing is estimated to be 12 billion won, which is about 4% of the investment cost of the private investment. In other words, it can be seen that the government will invest 12 billion won in financial support by sharing the investment risk. The option value when assuming the traffic volume risk as a random variable from the case studies is derived as an average of 12.2 billion won and a standard deviation of 3.67 billion won. As a result of the cumulative distribution, the option value of the 90% probability interval will be determined within the range of 6.9 to 18.8 billion won. The method proposed in this study is expected to help government and private investors understand the better risk analysis and economic value of better for investment risk sharing under the uncertainty of future demand.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.255-262
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• 1997

Purpose : This is retrospective study to compare the results of radiation therapy alone and neoadjuvant chemotherapy and radiation in advanced stage of uterine cervical cancer. Materials and Methods : Seventy-six Patients who were treated with definitive radiation therapy for locally advanced cervical cacinoma between June 1988 and December 1993 at the department of radiation oncology, Keimyung University Dong-san Hospital. Thirty six patients were treated with radiation therapy alone and forty patients were treated with cisplatin based neoadjuvant chemotherapy and radiation therapy. According to FIGO staging system. there were 48 patients in stage IIb, 3 patients in stage IIIa, 23 patients in stage lIIb and two patients in stage IVa with median age of 53 years old. Follow-up periods ranged from 7 to 95 months with median 58 months. Results : Complete response (CR) rate were $86.1\%$ in radiation alone group and $80\%$ in chemoradiation group. There was no statistical difference in CR rate between the two groups. Overall five-year survival rate was $67.3\%$. According to stage, overall five-rear survival rates were $74\%$ in stage IIb, $66.7\%$ in stage IIIa, $49.8\%$ in stage IIb, $50\%$ in stage IVa. According to treatment modality overall five year survival rates were $74.1\%$ in radiation alone and $61.4\%$ in chemoradiation group (P=0.4) Five rear local failure free survival rates were $71.5\%$ in radiation alone group and $60\%$ in chemoradiation group (P=0.17). Five year distant metastasis free survival rates were $80.7\%$ in radiation aione group and $89.9\%$ in chemoradiation group (P=0.42). Bone marrow suppression (more than noted in 3 cases of radiaion alone group and 1 case of chemoradiation group. Grade II retal complication was noted in 5 patients of radiation group and 4 patients In chemoradiation group. Bowel obstruction treated with conservative treatment (1 patient) and bowel perforation treated with surgery (1 patient) were noted in radiation alone group. There was no statistical difference in complication between two groups. Conclusion : There was no statistical difference in survival, failure and complication between neoadjuvant chemotherapy and radiation versus radiation alone in locally advanced uterine cervical carcinoma.

• Journal of Chest Surgery
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• v.43 no.5
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• pp.499-505
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• 2010

Background: There have been several reports using animal experiments that CD1-restricted T-cells have a key role in tumor immunity. To address this issue, we studied the expression of markers for CD1c+ myeloid dendritic cells (DCs) isolated from peripheral blood in the clinical setting. Material and Method: A total of 24 patients with radiologically suspected or histologically confirmed lung cancer who underwent pulmonary resection were enrolled in this study. The patients were divided according to histology findings into three groups: primary adenocarcinoma of lung (PACL), primary squamous cell carcinoma of lung (PSqCL) and benign lung disease (BLD). We obtained 20 mL of peripheral venous blood from patients using heparin-coated syringes. Using flow-cytometry after labeling with monoclonal antibodies, data acquisition and analysis were done. Result: The ratio of CD1c+CD19- dendritic cells to CD1c+ dendritic cells were not significantly different between the three groups. CD40 (p=0.171), CD86 (p=0.037) and HLA-DR (p=0.036) were less expressed in the PACL than the BLD group. Expression of CD40 (p=0.319), CD86 (p=0.036) and HLA-DR (p=0.085) were less expressed in the PACL than the PSqCL group, but the differences were only significant for CD86. Expression of co-stimulatory markers was not different between the PSqCL and BLD groups. Expression of markers for activated DCs were dramatically lower in the PACL group than in groups with other histology (CD40 (p=0.005), CD86 (p=0.013) HLA-DR (p=0.004). Conclusion: These results suggest the possibility that CD1c+ myeloid DCs participate in control of the tumor immunity system and that low expression of markers results in lack of an immune response triggered by dendritic cells in adenocarcinoma of the lung.