• Journal of the Korean Society for Marine Environment & Energy
• /
• v.5 no.2
• /
• pp.3-18
• /
• 2002

This study has been carried out to find the water Quality in coastal sea of fungmun area, southern Jeju Island. In-situ observations and water sampling had been made every month from July 1997 to June 2000. The distributions of water temperature and salinity over the study area have been 13.8~27.0℃ and 30.0~34.7‰, respectively. Salinity is showed low salinity from June to September (rainy season) because of rain. Tsushima Warm Waters (TWW) as ≥15℃ and ≥34‰ influence the adjacent sea around Jeju Island all year round. Yangtse Coastal Waters (YCW) influence the surface layer around Jeju from June to September and so strong stratification (termocline, halocline) resulted at the depth of between 20~30m at outer-sea. However the stratification does not happen even in summer at inner-sea, which seem to be caused due to vertical mixing by wind, waves and tides. A water mass of high value of water temperature and salinity (respectively 14.1~17.7℃, 33.9~34.1‰) stayed at the lower layer in outer-sea all the year round. It is probably formed by mixing between TWW and YSBCW(Yellow Sea Bottom Cold Water). The mean value of DO was the lowest in summer and the highest in winter. COD and TH were the highest in summer and the lowest in winter. However, TP showed the lowest value in summer season, because the mean value of N/P ratio was over 16. The mean of N/P ratio was under 16 in other seasons. The phosphate would be a limiting factor in the growth of phytoplanHon in summer. Nitrate would be a limiting factor in other seasons. Distribution of chlorophyll a did not show any seasonal change in the study period, but especially increased during April and May in the first year(1998) and the second year(1999) all over the study area, which suggested that phytoplankton inhabitation distributed widely in the study area. The space averaged values were the highest for TIN in rainy season and lower for TP in rainy season than in other seasons. It suggests that river runoff influences the inner-sea.

• Fisheries and Aquatic Sciences
• /
• v.20 no.11
• /
• pp.30.1-30.10
• /
• 2017

Small-scale fish farmers in developing countries are faced with challenges owing to their limited information on aquaculture management. Nile tilapia farmers in Teso North Sub-County recorded lower yields than expected in 2009 despite having been provided with required inputs. Water quality was suspected to be the key factor responsible for the low yields. This study sought to assess the effects of earthen pond water physico-chemical parameters on the growth of Nile tilapia in six earthen fish ponds under semi-intensive culture system in Teso North Sub-County. The study was longitudinal in nature with pond water and fish being the units of analysis. Systematic sampling was used to select five ponds while a control pond was purposively selected based on its previously high harvest. Four ponds were fed by surface flow and two by underground water. Each pond was fertilized and stocked with 900 fry of averagely 1.4 g and 4.4 cm. Physico-chemical parameters were measured in-situ using a multi-parameter probe. Sixty fish samples were randomly obtained from each pond fortnightly for four months using a 10 mm mesh size and measured, weighed and returned into the pond. Mean range of physico-chemical parameters were: dissolved oxygen (DO) 4.86-10.53 mg/l, temperature $24-26^{\circ}C$, pH 6.1-8.3, conductivity $35-87{\mu}S/cm$ and ammonia 0.01-0.3 mg/l. Temperature (p = 0.012) and conductivity (p = 0.0001) levels varied significantly between ponds. Overall Specific Growth Rate ranged between 1.8% (0.1692 g/day) and 3.8% (1.9 g/day). Ammonia, DO and pH in the ponds were within the optimal levels for growth of tilapia, while temperature and conductivity were below optimal levels. As temperature and DO increased, growth rate of tilapia increased. However, increase in conductivity, pH and ammonia decreased fish growth rate. Temperature and DO ranging between 27 and $30^{\circ}C$ and 5-23 mg/l, respectively, and SGR of 3.8%/day and above are recommended for higher productivity.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.9
• /
• pp.1003-1012
• /
• 2007

In this study, we analyzed the release differences for some critical pollution compounds according to the surrounding conditions in order to predict water quality due to the sedimental releases and the release characteristics at different sedimental locations in Lake Leewon, in Tae-An area. COD, nitrogens and phosphates were analyzed using the standard methods for water quality, based on high chloride ion concentration(greater than 2,000 ppm). For COD, the release rate increased in the anoxic basin but almost the same in the oxic basin. For $NH_3$-N, the release rate decreased in the oxic basin as you go A through C point meanwhile, for $NO_3$-N and T-N, the tendency was reversed because of nitrification of them. In the anoxic basin, the release rates of $NH_3$-N and $NO_3$-N went up with A through C path. However, the release rate of T-N was found to decrease. Also, for $PO_4$-P and T-P, the release rates in the oxic basin were lowest at B point mainly because the phosphates were at less released in the highly $O_2$ concentrated environment. In the anoxic reactor, $PO_4$-P was released similarly regardless of the sampling points. In summary, the release rates in the oxic reactor were greater than those in the anoxic reactor for COD and $NO_3$-N. For the other components, the anoxic basin generated the higher release rates.

• Journal of Korean Society of Rural Planning
• /
• v.21 no.3
• /
• pp.155-169
• /
• 2015

As an essential means to the exploitation of new demands, the export of agri-food has the price-supporting effect on the domestic agri-food and its expansion can be a good way to increase farms' income. Of course, to enhance farms' income under the liberalization of the market, it is necessary to have countermeasures considering various factors. To this end, the study understood the experiences of farms doing exports and looked into ways to improve them by reviewing their motivations to export, difficulties, requirements, etc. In this context, the study conducted the purposive sampling among tomato export farmhouses in Jeongseon-gun in the export enforcement phase and executed the theme analysis. The research findings and suggestions are as follows. First, in order to enhance the level of commercialization of Jeongseon-gun tomatoes and reinforce the trade bargaining power, it is necessary to form the consensus on policy and make the scaling of the site based on the strong organization power. To this end, it requires the active role of agricultural cooperatives that take a big portion of distribution in the site and distribute its profits directly to farmhouses. Second, it is necessary to set clear target markets for Jeongseon-gun tomato export farms and set sales strategies for each target market. That is, in order to expand the export of Jeongseon-gun tomatoes, after clarifying local sales and export sales, export farmhouses should focus on quality management and secure the quantity for export. Third, to expand the export to Japan which already has the foundation for the export of Korean tomatoes, and to new export countries of China, Russia, etc., it is necessary to set the 'Two-Track Strategies for Export Market (particular item for focus and particular area for focus)' through the building of network of tomato export areas in Gangwon-do. In conclusion, to expand the export of Jeongseon-gun tomatoes, agricultural cooperatives and leaders together should build the strong organizational power with farmhouses and secure the quantities for export. And, according to the 'Two-Track Strategies for Export Market (particular item for focus and particular area for focus)', export infrastructure and export operational system should be built and to do so, the solidarity of tomato export farmhouses in Gangwon area should precede.

• Journal of Chest Surgery
• /
• v.23 no.6
• /
• pp.1204-1212
• /
• 1990

Recent social and medical developments have significantly changed both the concept of death and the criteria for its pronouncement. Instead of considering. the heart as central to the determination for death, it is now prevalent to use death of the brain as adequate for death regardless of cardiac function in most western countries. But the brain death theory is not yet legally accepted despite growing public interest in our country due mainly to customary and moral reasons. Subsequently heart transplantation, which necessitates the concept of brain death, still remains a possible surgical entity in the future. As a part of endeavor the evaluate social atmosphere for the legal acceptance of the concept of brain death and the availability of potential heart donors, a four-page questionnaire on brain death and cardiac transplantation was given to the sophomore students of a medical college in Seoul[n=116, group I] and their family members[n=83, group II ]. The groups were chosen under the assumptions that they lacked sophisticated medical knowledge but had general medical interest so reliable data could be obtained. The majority of respondents in both group I and II thought that they knew the concept of brain death[group I 99.1%, group II 93.3%] and the definition of heart transplantation[group I 94%, group II 67.6%] at least to some extent, but only a small proportion of them was proven to have correct knowledge: brain death[74.4%, group II 39. 8%], heart transplantation[group I 31.9%, group II 30.1%]. Most respondents answered in the affirmative for the legal approval of brain death[group I 87.8%, group Il 97.9%]. The possibility of medical usage of brain dead organs was the biggest reason for brain death[group I 52.9%, group Il 47.9%]. Ninety-one percent of group I and 89.1 percent of group II responded that they were willing to give permission for donating the heart of brain-dead family members. Fifty-nine percent of group I and 51.9 percent of group II wanted their own heart donated. These results suggest, despite some inherent sampling limitations, that favorable responses to brain death and heart transplantation can be obtained among the general public if they are properly informed.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.4
• /
• pp.307-316
• /
• 2009

Soil microbial activity and diversity are affected by organic sources applied to improve soil quality and fluctuate seasonally. We investigated the effects of municipal compost (MC), poultry litter (PL), and cover crops of spring oats and red clover (RC) on soil enzyme activities, and soil bacterial community-level physiological profiling (CLPP) in a Mexico silt loam in North Central Missouri, USA. Temporal patterns of these parameters were observed by periodic five soil sampling from spring to fall over a two year period. MC increased soil dehydrogenase (DH) activity consistently beginning about three months after MC application; fluorescein diacetate (FDA) hydrolytic activity significantly began to increase by the September of the first year but fluctuated during the following period. DH activity responded more directly to the amount or properties of organic residues in soils while FDA hydrolysis and CLPP were generally influenced by composition of organic sources, and enzyme activities and CLPP showed seasonal variation, which depended on organic sources and soil moisture. MC and cover crops may be useful organic sources for enhancing general soil microbial activity and altering soil microbial diversity, respectively. Because microbial activities and diversity are dynamic and subject to seasonal changes, the effects of organic amendments on these parameters should be investigated frequently during a growing season.

• Journal of Forest and Environmental Science
• /
• v.33 no.3
• /
• pp.202-225
• /
• 2017

Non Timber Forest Products (NTFPs) has gained a lot of significance over the years as a means of income generation. Forests are playing a vital role in the supply of these products, however, due to their continuous extraction, the population of many species might have depleted. Very little information is known about community structure and population status of NTFPs. No specific studies have been made to find out the occurrence, availability of species and population status in the forests, supplying the resources. The present study has been carried out in community forests of the naturally occurring NTFPs in the temperate forest of the Ziro valley of Arunachal Pradesh. The main aim is to determine community structure, species composition and population status of NTFPs. Three forest stands viz., Nyilii, Dura and Gyachi were selected which are used by the Apatani tribe for extraction of the NTFPs. For evaluation of species composition and community characteristics, the sampling of the vegetation was done using the quadrat method. A total 137 species representing 68 families and 116 genera were recorded. Herbs represent the maximum diversity with 71 species followed by 35 shrub species and 31 tree species. The families Asteraceae and Rosaceaeae exhibited maximum representation followed by Urticaceae. The species under Fagaceae, Lauraceae, Rosaceae and Rutaceae were found to be important NTFP yielding species. Highest species richness was recorded in Nyilii having 124 species, while lowest in Dura with 102 species. Density of tree, shrub and herb ranged between 376 to $456\;individuals\;ha^{-1}$, 2848 to $3696\;individuals\;ha^{-1}$ and 31.44 to $36.64\;individuals\;m^{-2}$, respectively. The total basal area was found to be highest ($51.64m^2\;ha^{-1}$) in Dura followed by Nyilii ($25.32m^2\;ha^{-1}$) and lowest in Gyachi ($22.82m^2\;ha^{-1}$). In all the three study stands the species diversity indices showed the trend, herbs > shrubs > trees while the evenness index showed the trend as shrubs > herbs > trees. The overall species similarity index was highest (82.35%) between Dura and Gyachi. About 80% of the total recorded species showed clumped distribution while, no regular distribution was shown by any species. The three selected stands harbor about 50 important NTFP yielding species which are being used commonly by the Apatani people in their day to day life. Among the three study sites, overall diversity of NTFP was found highest in the Nyilii stand while the density of population was found better in Dura and Gyachi stands. The population of many species was found to be low due to continue harvesting without any sustainable management by the communities. All the selected forest stands have the potentiality to grow the high value NTFP yielding species and if managed properly, they can support the livelihood and economy of the local communities.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.27 no.5
• /
• pp.429-436
• /
• 2014

This paper presents the seismic performance of a geometrically unsymmetrical reinforced concrete building considering torsional effect and material nonlinearity of concrete and steel. The reinforced concrete building is a structure for seismic performance evaluation in the SMART-2013 international benchmark program. Nonlinear constitutive models for concrete and steel were constructed, and their numerical performance was demonstrated by various local tests. Modal analysis showed that the first three natural frequencies and mode shapes were close to the experimental results from the SMART-2013 program. In the time history analysis for low-intensity seismic loadings, displacement and acceleration responses at sampling points were similar to the experimental results. In the end, nonlinear time history analysis was conducted for Northridge earthquake to predict the behavior of the reinforced concrete structure under high-intensity seismic loadings.

• Korean Journal of Health Education and Promotion
• /
• v.3 no.1
• /
• pp.43-55
• /
• 1985

The recent problems of adolescents are leading us to amphasize school mental health program. Therefore, for the first step of that program, this study was attempted to find out the students' daily life stress, their adaptation beharior to resolve that stress, and their self-concept which has an effect on that beharior, to analyze the relationship among those three variables, and to provide basic data which help maintain and promote students' adaptability and mental health. The subjects were 4 classes each grade, 743 students who were chosen as a sample subject among the total of 3,250 students of a junior girls' school in Seoul by stratified sampling method. The Oquestionnair surrey was done from April 1, 1985 to April 6, 1985. The instruments were (1) a part of Junghoon chois' perceptual Orientation Scale for measuring self-perception of students, (2) Rosenberg's Questionnair for measuring students' evaluation of self-esteem, (3) modified Bell's Adoptive Behavior Questionnair, and (4) the Measuring scale for stress developed by the investigator. The collected data were analyzed by using descriptive statistics, x²-test, t-test, ANOVA, and Pearsons' Correlation. The results are summarized as follows: 1. The range of mean score of self-concept, stress, and adaptation beharior is 1-5 respectively. The mean score of self concept was 3.45. The mean score of stress was 2.53, and the degree of stress was in order of the problem of study and grade marks, girl friend, appearance, and relaxation. The subjects preferred effective long-term adaptation method (Mean=2.81) to ineffective short-term adaptation method. (Mean=2.47) 2. The self-concept had the highest degree when students were 1st grade, in good health condition, taking high grade marks, both parents existing, fathers' educational level being above college, and being in high economic status. The degree of stress was significantly high when students were 3rd grade, in poor health condition, having low grade marks, being in poor economic status, and fathers' educational level being under elimentary school. In relation with adaptation method, 1st grade students used more sbort-term and long-term method, and when students had high grade marks, being in high economic status. they used more long-term adaptation behavior. 3. Two Hypotheses of this research were tested: Hypothesis 1. "The higher the students' self-concept is, the more they use long-term adaptation method." was accepted. (r=.2482, p<.01) (t=-4.99, p<.001) Hypothesis 2. "The higher the students' stress is, the more they use short-term adaptation method." was accepted. (r=.2897, p<.01) (t= -7.51, p<.001) In conclusion, a person in charge of school health can help students to adapt effectively by planning and implementing methods which highten their self-concept and lower their stress. But because the correlation among self-concept, stress and adaptation behavior was at a low level, I think that the study, which confirm the relationship of those three variables, is needed.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.10
• /
• pp.57-63
• /
• 2014

This paper proposes an architecture of $3^{rd}$ order SDM(Sigma-Delta Modulator) with delayed feed-forward path in order to reduce the power consumption and area. The proposed SDM improve the architecture of conventional $3^{rd}$ order SDM which consists of two integrators. The proposed architecture can increase the coefficient values of first stage doubly by inserting the delayed feed-forward path. Accordingly, compared with the conventional architecture, the capacitor value($C_I$) of first integrator is reduced by half. Thus, because the load capacitance of first integrator became the half of original value, the output current of first op-amp is reduced as 51% and the capacitance area of first integrator is reduced as 48%. Therefore, the proposed method can optimize the power and the area. The proposed architecture in this paper is simulated under conditions which are supply voltage of 1.8V, input signal 1Vpp/1KHz, signal bandwidth of 24KHz and sampling frequency of 2.8224MHz in the 0.18um CMOS process. The simulation results are SNR(Signal to Noise Ratio) of 88.9dB and ENOB(Effective Number of Bits) of 14-bits. The total power consumption of the proposed SDM is $180{\mu}W$.