• Journal of Environmental Impact Assessment
• /
• v.8 no.3
• /
• pp.35-47
• /
• 1999

The purpose of this study is to research the environmental amenity factors of a city to devise the strategies to preserve the factors. For this study, the area of Masan city in Korea was chosen, and questionnaires, field studies, and statistical researches were used. Based on the results, the research showed the city surveyed had expanded by 1,069%, and the population of the city had increased by 272% from 1970 to 1995. In the city-life environment, the traffic was not smooth and the streets were not safe. The number of cars increased by 40,797% from 1970 to 1995, but the total length of roads increased only by 333%. The number of traffic accidents increased by 850%. Buildings were not preserved or maintained and did not have any traditional value. Additionally, buildings were not harmonious with environmental surroundings. Land allocation for utilization was not mixed well with tradition. In relation with the surroundings, there were not enough spaces for old people, and parking spaces were limited. In the field of public policy and finance, economic support and fundamental facilities were not enough. The survey of the household environment and the neighborhood environment showed that the room temperature, sunshine, air condition, and space were medial in the household environment. Public social facilities and entertainment culture had the lowest quality in the neighborhood environment. The city-life environment, the neighborhood environment, and the household environment affected the quality of life in order. The above results showed that cities should be planned upon sustainable development with the idea of emphasizing ecological harmony and considering people first, that citizen should be planned upon sustainable life by the harmony between people and the environment. Cities should be places where all people can live together pleasantly and cooperate with each other.

• Journal of Veterinary Clinics
• /
• v.26 no.1
• /
• pp.72-75
• /
• 2009

Pulmonary bullae are air-filled spaces within the lung parenchyma that result from the destruction, dilatation and confluence of adjacent alveoli. Pulmonary bullae are found most often in healthy, middle aged, large breed or deep-chested dogs that have no previous history of lung disease and bulla may occur as a result of emphysema, inflammation or trauma. Clinical signs include respiratory distress, anorexia, depression and tachypnea. In this study, a dog with respiratory distress by traffic accident was diagnosed as pulmonary bullae with pneumothorax using radiography at Veterinary Medical Teaching Hospital, GNU. In radiographs, various sized, smooth margin, well defined, oval shaped, gas or fluid filled multiple bullae are shown in the left cranial, left caudal and right accessory lobes. At the initial stage of observation, there were indications of four bullae, two of which were not found in the following radiograph. At the same time, there were serious indications of lung consolidation that caused respiratory distress of patient. Ultimately, the patient was expired after ten hours.

• Journal of the Korean Mathematical Society
• /
• v.34 no.3
• /
• pp.731-770
• /
• 1997

We study Diriclet forms and related subjects for the Gibbs measures of classical unbounded sping systems interacting via potentials which are superstable and regular. For any Gibbs measure $\mu$, we construct a Dirichlet form and the associated diffusion process on $L^2(\Omega, d\mu), where \Omega = (R^d)^Z^\nu$. Under appropriate conditions on the potential we show that the Dirichlet operator associated to a Gibbs measure $\mu$ is essentially self-adjoint on the space of smooth bounded cylinder functions. Under the condition of uniform log-concavity, the Gibbs measure exists uniquely and there exists a mass gap in the lower end of the spectrum of the Dirichlet operator. We also show that under the condition of uniform log-concavity, the unique Gibbs measure satisfies the log-Sobolev inequality. We utilize the general scheme of the previous works on the theory in infinite dimensional spaces developed by e.g., Albeverio, Antonjuk, Hoegh-Krohn, Kondratiev, Rockner, and Kusuoka, etc, and also use the equilibrium condition and the regularity of Gibbs measures extensively.

• Korean Journal of Animal Reproduction
• /
• v.25 no.4
• /
• pp.399-407
• /
• 2001

The microinjection of retroviral vectors into the perivitelline spaces of MII-stage oocytes increased production of transgenic bovine embryos. However, oocytes have various sizes of perivitelline space, and there is the tendency that the oocyte membranes are damageable by micropipettes during the injection of retroviral vectors into perivitelline spaces or oocytes. Thus, it was not always possible to stably inject retroviral vector into perivitelline spaces of oocytes. Here we used sucrose to minimize the damage of the oocyte membrane. When the oocytes were suspended in 0.5% sucrose, poor quality oocytes showed rough cytoplasmic membranes, while good quality oocytes maintained smooth membranes. However, when the tatters were subjected to in vitro fertilization, no significant differences were observed in cleavage rates (82% of control Vs. 84% of sucrose treated oocytes). The Same trends were obtained from the oocytes fertilized after microinjection of LN$\beta$-EGFP and LNC-hGH genes into the perivitelline spares. The rates of cleavage and blastocyst from microinjection of LN$\beta$-EGFP genes were 81 and 25%, and from microinjection of LNC-hGM genes were 53 and 30%, respectively. The result indicated that microinjected oocytes could develop to the blastocyst stages after in vitro fertilization with no significant difference from control group. Moreover, the integration of hGH-gene (by PCR analysis) was detected in 52% of infected cleaved embryos and the expression of EGFP-gene (under a fluoresrence microscope) was also observed in 34% of infected blastocyst. These results indicated that 0.5% sucrose treatment could be an efficient method not only to select good quality embryos but also to inject retroviral vectors into perivitelline spares without any harm and hence improving developmental rates.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.4
• /
• pp.343-352
• /
• 2013

In this study, a smooth flat surface, low fin, Turbo-B, and Thermoexcel-E surfaces are used to examine the effect of the flow velocity on the pool boiling heat transfer coefficients (HTCs) and critical heat fluxes (CHFs). HTCs and CHFs are measured on a smooth square heater of $9.53{\times}9.53mm^2$ at $60^{\circ}C$ in a pool of pure water at various fluid velocities of 0, 0.1, 0.15, and 0.2 m/s. Test results show that for all surfaces, CHFs obtained with flow are higher than those obtained without flow. CHFs of the low fin surface are higher than those of the Turbo-B and Thermoexcel-E surfaces due largely to the increase in surface area and sufficient fin spaces for the easy removal of bubbles. CHFs of the low fin surface show even 5 times higher CHFs as compared to the plain surface. On the other hand, both Turbo-B and Thermoexcel-E surfaces do not show satisfactory results because their pore sizes are too small and water bubbles easily cover them. At low heat fluxes of less than $50kW/m^2$, HTCs increase as the flow velocity increases for all surfaces. In conclusion, a low fin geometry is good for application to steam generators in nuclear power plants.

• Applied Microscopy
• /
• v.28 no.3
• /
• pp.315-328
• /
• 1998

The present study was carried out to investigate the effect of ultrasonic bath in tissue preparation for transmission electron microscopy. The method used standard reagents and media, and employed ultrasonic bath agitation to accelerate fluid exchange. The liver kidney, stomach and cardiac muscle tissues of male Sprague-Dawley rats were used for the experiment, and the experimental design was divided into 4 groups; The control group using rotators (Traditional method, 1,625 mins) and the three experimental groups using ultrasonic bath (UB) in the primary fixation through the infiltration processes (UB I; 62.5 mins, UB II; 125 mins, UB III; 250 mins). The results were as follows; 1. In the control group, tissues were easily sectioned, and showed well preserved intact membranes, and cell organelles such as mitochondria, lysosome, peroxisome, rough endoplasmic reticulum and smooth endoplasmic reticulum. 2. In the UB treated group I, tissues showed holes due to the inadequate removal of both water and fluids used in the dehydration process. Also the mitochondria of cell organelles, especially, showed swollen intracristal spaces and dense matrices due to poor fixation. 3. In the UB treated group II, tissues showed good preservation of cell organelles and specimen slice sections. Also, no holes were observed. 4. In the UB treated group III, tissues showed leaching of structural components in the cytoplasm, but no holes were observed. In conclusion, the ultrasonic bath procedure takes approximately 120 minutes from specimen fixation to resin infiltration and gives excellent results.

• Applied Microscopy
• /
• v.28 no.1
• /
• pp.91-105
• /
• 1998

The present study is undertaken to investigate the hypertrophical changes of the corpus allatum (corpora allata, CA) after the ovariectomy in Blattella germanica. In particular, the ultrastructural aspects of the normal and ovariectomized conditions, and induced factors of the hypertrophic phenomenon are focused. Ultrastructure of the CA from an immediately emergent adult is similar to that of the last larval stage that has stopped secreting juvenile hormone. The CA is composed of undifferentiated cells, exhibiting an electron-lucent matrix, a few mitochondria and less smooth endoplasmic reticulum. The karyoplasm occupy most of the cytoplasm. Electron-dense materials are filled with the intercellular spaces and gap junctions are also found. Almost no ultrastructural changes have been noticed during seven days until the oviposition. However, considerable changes in structure have been detected soon after the oviposition. Mitochondria are increased dramatically in number and cristae, and changed to the filamentous form with a high electron density. In addition, Golgi complexes, microtubules, and polysomes are also increased. After an oviposition, the total volume of the CA are decreased again. The volume of the CA are increased continuously, hypertrophy, after the ovariectomy. Morphological aspects of the CA in an early stage after the removal are similar to the structure of the secondary egg maturation. Large and electron dense globules are observed in the ovariectomized CA cytoplasms and they are present in those cells for a long period of time. Yet such a hypertrophical phenomenon occur only in the specific cells. The hypertrophy are caused by hollowing the part of the CA cells and later filling such site with polysomes. In 42 days after the ovariectomy, the nuclear membranes disappear in the CA cells, thus, exhibiting the prokaryotic-like features. Some results of the current study will contribute to the establishment of the model that explain unusual changes accompanied by certain treatment in insects and/or further in animals.

• Journal of the Korean Mathematical Society
• /
• v.54 no.5
• /
• pp.1483-1504
• /
• 2017

We consider weak solutions of the instationary Navier-Stokes system in a smooth bounded domain ${\Omega}{\subset}{\mathbb{R}}^3$ with initial value $u_0{\in}L^2_{\sigma}({\Omega})$. It is known that a weak solution is a local strong solution in the sense of Serrin if $u_0$ satisfies the optimal initial value condition $u_0{\in}B^{-1+3/q}_{q,s_q}$ with Serrin exponents $s_q$ > 2, q > 3 such that ${\frac{2}{s_q}}+{\frac{3}{q}}=1$. This result has recently been generalized by the authors to weighted Serrin conditions such that u is contained in the weighted Serrin class ${{\int}_0^T}({\tau}^{\alpha}{\parallel}u({\tau}){\parallel}_q)^s$ $d{\tau}$ < ${\infty}$ with ${\frac{2}{s}}+{\frac{3}{q}}=1-2{\alpha}$, 0 < ${\alpha}$ < ${\frac{1}{2}}$. This regularity is guaranteed if and only if $u_0$ is contained in the Besov space $B^{-1+3/q}_{q,s}$. In this article we consider the limit case of initial values in the Besov space $B^{-1+3/q}_{q,{\infty}}$ and in its subspace ${{\circ}\atop{B}}^{-1+3/q}_{q,{\infty}}$ based on the continuous interpolation functor. Special emphasis is put on questions of uniqueness within the class of weak solutions.

• Journal of The Korean Astronomical Society
• /
• v.46 no.3
• /
• pp.125-131
• /
• 2013

We present the relation between the genus in cosmology and the Betti numbers for excursion sets of three- and two-dimensional smooth Gaussian random fields, and numerically investigate the Betti numbers as a function of threshold level. Betti numbers are topological invariants of figures that can be used to distinguish topological spaces. In the case of the excursion sets of a three-dimensional field there are three possibly non-zero Betti numbers; ${\beta}_0$ is the number of connected regions, ${\beta}_1$ is the number of circular holes (i.e., complement of solid tori), and ${\beta}_2$ is the number of three-dimensional voids (i.e., complement of three-dimensional excursion regions). Their sum with alternating signs is the genus of the surface of excursion regions. It is found that each Betti number has a dominant contribution to the genus in a specific threshold range. ${\beta}_0$ dominates the high-threshold part of the genus curve measuring the abundance of high density regions (clusters). ${\beta}_1$ dominates the genus near the median thresholds which measures the topology of negatively curved iso-density surfaces, and ${\beta}_2$ corresponds to the low-threshold part measuring the void abundance. We average the Betti number curves (the Betti numbers as a function of the threshold level) over many realizations of Gaussian fields and find that both the amplitude and shape of the Betti number curves depend on the slope of the power spectrum n in such a way that their shape becomes broader and their amplitude drops less steeply than the genus as n decreases. This behaviour contrasts with the fact that the shape of the genus curve is fixed for all Gaussian fields regardless of the power spectrum. Even though the Gaussian Betti number curves should be calculated for each given power spectrum, we propose to use the Betti numbers for better specification of the topology of large scale structures in the universe.

• Korean Journal of Materials Research
• /
• v.20 no.12
• /
• pp.661-668
• /
• 2010

Cu(In,Ga)$Se_2$(CIGS) photovoltaic thin films were electrodeposited on Mo/glass substrates with an aqueous solution containing 2 mM $CuCl_2$, 8 mM $InCl_3$, 20 mM $GaCl_3$ and 8mM $H_2SeO_3$ at the electrodeposition potential of -0.6 to -1.0 V(SCE) and pH of 1.8. The best chemical composition of $Cu_{1.05}In_{0.8}Ga_{0.13}Se_2$ was found to be achieved at -0.7 V(SCE). The precursor Cu-In-Ga-Se films were annealed for crystallization to chalcopyrite structure at temperatures of 100-$500^{\circ}C$ under Ar gas atmosphere. The chemical compositions, microstructures, surface morphologies, and crystallographic structures of the annealed films were analyzed by EPMA, FE-SEM, AFM, and XRD, respectively. The precursor Cu-In-Ga-Se grains were grown sparsely on the Mo-back contact and also had very rough surfaces. However, after annealing treatment beginning at $200^{\circ}C$, the empty spaces between grains were removed and the grains showed well developed columnar shapes with smooth surfaces. The precursor Cu-In-Ga-Se films were also annealed at the temperature of $500^{\circ}C$ for 60 min under Se gas atmosphere to suppress the Se volatilization. The Se amount on the CIGS film after selenization annealing increased above the Se amount of the electrodeposited state and the $MoSe_2$ phase occurred, resulting from the diffusion of Se through the CIGS film and interaction with Mo back electrode. However, the selenization-annealed films showed higher crystallinity values than did the films annealed under Ar atmosphere with a chemical composition closer to that of the electrodeposited state.