• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.147-153
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• 2010

A study was carried out to examine the effect of water temperature on daily pattern and rate of total ammonia nitrogen (TAN) excretion in juvenile Pacific cod Gadus macrocephalus (mean body weight: $36.5{\pm}0.8\;g$) under fasting and feeding conditions. Fish were acclimated over 10 days under three different water temperatures (9, 11 and $13^{\circ}C$), and transferred to TAN measuring system under each water-temperature condition. After 72 hours of starving, fasting TAN excretion was measured at each temperature. To investigate post-prandial TAN excretion, fish were hand-fed with a commercial diet containing 40.6% crude protein for 7 days, two times daily at 08:00 and 16:00 h. Water was sampled from both the inlet and outlet of the fish chamber every 2 h over a 24-h period. Both fasting and post-prandial TAN excretion increased with increased water temperatures (p<0.05). Mean fasting TAN excretion rates at 9, 11 and $13^{\circ}C$ were 9.3, 11.0 and $11.9\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. The value of $9^{\circ}C$ was lower than those of 11 and $13^{\circ}C$ (p<0.05), but there was no significant difference between $11^{\circ}C$ and $13^{\circ}C$. Mean post-prandial TAN excretion rates at 9, 11 and $13^{\circ}C$ were 23.0, 31.6 and $45.4\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. A peak value of post-prandial TAN excretion rate occurred after 2 h from each feeding, and the second value is always higher than the first value. Maximum post-prandial TAN excretion rate occurred after 10 h from the first feeding at $9^{\circ}C$ (mean $38.0\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), $11^{\circ}C$ ($52.9\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$) and $13^{\circ}C$ ($77.5\;mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), respectively. The TAN loss for ingested nitrogen at $9^{\circ}C$ (43.9%) was lower than those of $11^{\circ}C$ (46.4%) and $13^{\circ}C$ (48.4%). The overall results indicate that water temperature exhibits a significant effect on the nitrogen excretion of juvenile Pacific cod.

• KDI Journal of Economic Policy
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• v.13 no.4
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• pp.31-57
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• 1991

Korean firms of all sizes, from virtually every industry, have used and are using the term "excessive competition" to describe the state of their industry and to call for government interventions. Moreover, the Korean government has frequently responded to such calls in various ways favorable to the firms, such as controlling entry, curbing capacity investments, or allowing collusion. Despite such interventions' impact on the overall efficiency on the Korean economy as well as on the wealth distribution among diverse groups of economic agents, the term "excessive competition", the basis for the interventions, has so far escaped rigorous scrutiny. The objective of this paper is to clarify the notion of "excessive competition" and "over-investment" which usually accompanies "excessive competition", and to examine the circumstances under which they might occur. We first survey the cases where the terms are most widely used and proceed to examine those cases to determine if competition is indeed excessive, and if so, what causes "excessive competition". Our main concern deals with the case in which the firms must make investment decisions that involve large sunk costs while facing uncertain demand. In order to analyze this case, we developed a two period model of capacity precommitment and the ensuing competition. In the first period, oligopolistic firms make capacity investments that are irreversible. Demand is uncertain in period 1 and only the distribution is known. Thus, firms must make investment decisions under uncertainty. In the second period, demand is realized, and the firms compete with quantity under realized demand and capacity constraints. In the above setting, we find that there is "no over-investment," en ante, and there is "no excessive competition," ex post. As measured by the information available in period 1, expected return from investment of a firm is non-negative, overall industry capacity does not exceed the socially optimal level, and competition in the second period yields an outcome that gives each operating firm a non-negative second period profit. Thus, neither "excessive competition" nor "over-investment" is possible. This result will generally hold true if there is no externality and if the industry is not a natural monopoly. We also extend this result by examining a model in which the government is an active participant in the game with a well defined preference. Analysis of this model shows that over-investment arises if the government cannot credibly precommit itself to non-intervention when ex post idle capacity occurs, due to socio-political reasons. Firms invest in capacities that exceed socially optimal levels in this case because they correctly expect that the government will find it optimal for itself to intervene once over-investment and ensuing financial problems for the firms occur. Such planned over-investment and ensuing government intervention are the generic problems under the current system. These problems are expected to be repeated in many industries in years to come, causing a significant loss of welfare in the long run. As a remedy to this problem, we recommend a non-intervention policy by the government which creates and utilizes uncertainty. Based upon an argument which is essentially the same as that of Kreps and Wilson in the context of a chain-store game, we show that maintaining a consistent non-intervention policy will deter a planned over-investment by firms in the long run. We believe that the results obtained in this paper has a direct bearing on the public policies relating to many industries including the petrochemical industry that is currently in the center of heated debates.

• Journal of Korean Society of Forest Science
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• v.58 no.1
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• pp.34-40
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• 1982

Main consideration of this trial is to know whether the planting work should be possible to do not only in the early spring but also in the summer or autumn, for giving the guide to get the work plan and to broaden the employing season of the skilled forest worker. Seedling of Pinus koraiensis, Larix leptolepsis, Pinus rigida, Pinus rigida${\times}$ P. taeda(wind) and Chamaecyparia obtusa as the test species had been planted in 15 days interval from the middle of March to the end of November. The seedling survival was investigated in the spring time of coming year because the winter damage could be problems. At the same time the climate data was measured daily and the shoot growth of test species were also measured in other near plantation at 15 days interval to know the influence to survival. From these results the spring and autumn planting is showing the good survival and the summer planting seems to give the difficulties. The spring planting in the southern temperate zone could be stared earlier as the end of February or beginning of March because the soil temperature are increasing up more $5^{\circ}C$ from this time. But the summer planting from the beginning of May until the end of August in better to avoid with excluding specially the good season of rainfall distribution because of the shoot growth of green confer seedling and the leave sprouting of Larix leptolepsis are so vigorously growing up from the begining of May and its wood structure is too weak to compensate the water loss. But among the test species Pinus koraiensis and Chamaecyparis obtusa have more possibility to plant in the summer season. The autumn planting seems to be very reasonable to accept newly in the trial region. This may be the reasons of still high soil temperature to grow the seedling root and of hardened school to resist from the dry winter wind. But it will be carefully that the strongly exposured site could be to avoid for the autumn planting in case of specially Pinus rigida${\times}$P. taeda and Chamaecyparis obtusa. From these discussion the guide table 1 for planting season with the test species is proposed and can be used for planing and employing in the trial zone.

• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.135-147
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• 2015

Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.855-866
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• 2017

Several research cases using remote sensing methods to analyze changes of storage and dynamics of groundwater aquifer were reviewed in this paper. The status of groundwater storage, in an area with regional scale, could be qualitatively inferred from geological feature, surface water altimetry and topography, distribution of vegetation, and difference between precipitation and evapotranspiration. These qualitative indicators could be measured by geological lineament analysis, airborne magnetic survey, DEM analysis, LAI and NDVI calculation, and surface energy balance modeling. It is certain that GRACE and InSAR have received remarkable attentions as direct utilization from satellite data for quantification of groundwater storage and dynamics. GRACE, composed of twin satellites having acceleration sensors, could detect global or regional microgravity changes and transform them into mass changes of water on surface and inside of the Earth. Numerous studies in terms of groundwater storage using GRACE sensor data were performed with several merits such that (1) there is no requirement of sensor data, (2) auxiliary data for quantification of groundwater can be entirely obtained from another satellite sensors, and (3) algorithms for processing measured data have continuously progressed from designated data management center. The limitations of GRACE for groundwater storage measurement could be defined as follows: (1) In an area with small scale, mass change quantification of groundwater might be inaccurate due to detection limit of the acceleration sensor, and (2) the results would be overestimated in case of combination between sensor and field survey data. InSAR can quantify the dynamic characteristics of aquifer by measuring vertical micro displacement, using linear proportional relation between groundwater head and vertical surface movement. However, InSAR data might now constrain their application to arid or semi-arid area whose land cover appear to be simple, and are hard to apply to the area with the anticipation of loss of coherence with surface. Development of GRACE and InSAR sensor data preprocessing algorithms optimized to topography, geology, and natural conditions of Korea should be prioritized to regionally quantify the mass change and dynamics of the groundwater resources of Korea.

• Radiation Oncology Journal
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• v.26 no.1
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• pp.1-9
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• 2008

Purpose: To evaluate the impact of postoperative radiotherapy on loco-regional failure in patients with vulvar carcinoma and to determine the treatment strategy for inguinal lymph nodes. Materials and Methods: Sixty-six patients who received treatment for primary vulvar carcinoma at Seoul National University Hospital, from October 1979 through June 2004, were retrospectively analyzed. Sixteen patients were excluded from the analysis due to the following reasons: distant metastases in two patients; palliative intent for six patients; previous radiotherapy given to the pelvis in three patients; follow-up loss after surgery for four patient; insufficient medical records for one patient. Of 50 eligible patients, 35 were treated with surgery alone(S), ten were treated with surgery followed by radiotherapy(S+RT), and five were treated with radiotherapy alone. Results: The 5-year overall survival(OS) and disease-free survival(DFS) rates of all patients were 91% and 78%, respectively. Twelve patients(26%) experienced treatment failures and the sites of initial failure were as follows: a primary site in eight patients; regional lymph nodes in three patients; the lung in one patient. Although risk factors for failure were more common in the S+RT group than the S group of patients(p<0.05), the DFS rates were similar for the two groups(5-year DFS rates, 78% vs. 83%, p=0.66). The incidences of occult lymph node metastases was 10%. Ten of 31 patients with clinically negative lymph nodes did not received inguinal lymph node dissection, but no patient experienced regional failure. Conclusion: Postoperative radiotherapy may have a potential benefit for patients with risk factors for failure. The omission of inguinal dissection or elective radiotherapy to the inguinal lymph nodes may be considered in low-risk patients with clinically negative lymph nodes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.4
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• pp.264-271
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• 2019

This study was conducted to investigate the effect of whole crop rice based TMR on the meat quality of Korean Native Cattle (Hanwoo). Sixteen Hanwoo steers (average 8 months old) were divided into the control group (commercially marketed TMR) and the WCR-TMR group (whole crop rice based TMR). Feeding trials were carried out up to 30 months of age, and after slaughter, the strip loin were collected and analyzed for meat quality. There were no significant differences in proximate compositions of Hanwoo (P>0.05), and crude protein, crude fat and crude ash were 19.51~20.23 %, 11.53~11.35 % and 1.10~1.12 %, respectively. There was no significant difference in water holding capacity and cooking loss between treatments (P>0.05), but it was slightly lower in the control group. Among the various functional components in meat, β-carotene was not detected, but α-tocopherol was significantly higher in WCR-TMR group and vitamin A content in control (P<0.05). The a^⁎-value in the meat color index decreased significantly with longer storage period in the control group, whereas the WCR-TMR fed group showed no significant difference (P>0.05) according to the storage period. There were no difference between the treatments in the TBARS (2-Thiobarbituric acid reactive substances) value used as an indicator of lipid oxidation and in fatty acid content. But the control group had high myristic acid content, whereas the WCR-TMR supplemented group showed higher oleic acid and linoleic acid content. In conclusion, feeding of WCR based-TMR increased the α-tocopherol content, which is a functional ingredient in meat, and the other components were not significantly different from the control. Therefore, it was judged that there was no significant difference between WCR based and conventional TMR in meat quality characteristics.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.864-871
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• 2014

Seed viability is affected by storage conditions and rapid loss of viability in storage is the major cause for low germination. This study was carried out to examine the effect of packaging materials and storage temperature on seed germination rate over 10 years in two species (Capsicum annuum L. and Brassica rapa L. ssp. pekinensis) and determine effective storage conditions for maintaining seed viability. Seeds were packaged in aluminum poly pouches under vacuum, polyethylene bottles, and paper bags containing silica gel and stored under one of two controlled conditions ($15^{\circ}C$, RH 40% or $5^{\circ}C$, RH 30%) or at ambient condition. Seed germination was recorded at 6-month intervals for 10 years. The seeds of both species showed no decline in viability until 6.5 years at 15 or $5^{\circ}C$, irrespective of packaging materials. However, under ambient conditions, the seeds of chili pepper and Chinese cabbage in paper bags lost viability after 4 and 5 years, respectively. By contrast, seeds of both species in vacuum-aluminum poly pouches exhibited a 99% germination rate after 6 years under ambient conditions. Pepper seeds in the vacuum-aluminum poly pouches maintained a 93% germination rate after 10 years in ambient conditions. These results indicated that a special seed storage facility for maintaining viability of chili pepper and Chinese cabbage seed might not be essential and seed testing would not be necessary for 10 years, if chili pepper and Chinese cabbage seeds were packed in ambient/vacuum-aluminum poly pouches or $5^{\circ}C$/vacuum-aluminum poly pouches.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.175-188
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• 2005

This study investigated the effects of silkworm droppings (SWD) added diet feeding on quality characteristics of pork loin meat Pigs were divided into 7 treatment groups (10 pigs/group) and subjected to one of seven treatment diets $(0,\;1\%,\;2\%\;and\; 3\%\;SWD\;for\;4 weeks,\;1\%\;2\%\;3\%$ SWD for 8 weeks, SWD diets; total fed diets) before slaughter. Pork loin were collected from the animals (110kg body weight) slaughtered at a commercial slaughterhouse. Pork loin meat were packaged aerobically and then stored at $4^{\circ}C$ for 2, 5, 8, or 12 days. Samples were analyzed for general composition, texture characteristics and physico-chemical properties. pH value was not significantly different between the control and SWD treatment groups. pH of control and SWD treatment groups were increased as the storage period passed General composition, cooking loss and texture was not significantly different between the control and SWD treatment groups. WHC of SWD treatment group was higher than that of control group. WHC of control and SWD treatment groups were significantly decreased as the storage period passed (p<0.05). Meat and fat color (CIE $L^{\ast}$, $a^{\ast}$, $b^{\ast}$) were no significant differences between the control and SWD treatment groups. $L^{\ast}$ and $b^{\ast}$ value of meat color were decreased as the storage period passed There was a not significantly difference in shear force value among control and SWD treatment groups. Shear force value was decreased significantly during storage in all treatment groups. In all results, dietary SWD-supplementation was not affected in general components, texture characteristics and physico-chemical properties. It is suggested that dietary SWD-supplementation could produce of high quality pork.

• Journal of radiological science and technology
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• v.27 no.4
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• pp.11-16
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• 2004

Classification of esophageal motility disorders not yet finalized and is still ongoing as the new disorders are reported, and the existing classification is changed or removed. In terms of radiology, the primary peristalsis does not exist, and the lower end of the esophagus show the smooth, tapered, beak-like appearance. The esophageal motility disorder, which mostly occurs in the smooth muscle area, show the symptoms of reduction or loss (hypomotility) or abnormal increase (hypermotility) of peristalsis of the esophagus. It is important to understand the anatomy and physiology of the esophagus for the appropriate radiological method and diagnosis. Furthermore, the symptom of the patient and the manometry finding must be closely referred for the radiological diagnosis. The lower esophageal sphincter can be normally functioning and open completely as the food moves lower. Sperandio M et al. argues that the name diffuse esophageal spasm must be changed to distal esophageal spasm (DES) as most of the spasm occurs in the distal esophagus, composed of the smooth muscle. According to Ott et al., usefulness of barium method for diagnosing the esophageal motility disorder is Achalasia 95%, DES 71% and NEMD 46%, with the overall sensitivity of 56%. However, excluding the nutcracker esophagus or nonspecific disorder which cannot be diagnosed with the radiological methods, the sensitivity increases to 89%. Using videofluoroscopy and 5 time swallows, the average sensitivity was over 90%. In conclusion, the barium method is a simple primary testing method for esophageal motility test. Using not only the image but also the videofluoroscopy with good knowledge of the anatomy and physiology, it is believed that the method will yield the accurate diagnosis.