• The Journal of the Petrological Society of Korea
• /
• v.7 no.1
• /
• pp.1-14
• /
• 1998

Dangsanbong volcano, which is located on the coast of the western promontory of Cheju Island, occurs in such a regular pattern on the sequences which represent an excellent example of an eruptive cycle. The volcano comprises a horseshoe-shaped tuff cone and a younger nested cinder cone on the crater floor, which are overlain by a lava cap at the top of the cinder cone, and wide lava plateau in the moat between two cones and in the northern part. The volcanic sequences suggest volcanic processes that start with Surtseyan eruption, progress through Strombolian eruption and end with Hawaiian eruption, and then are followed by rock fall from sea cliff of the tuff cone and by air fall from another crater. It is thought that the eruptive environments of the tuff cone could be mainly emergent because the present cone is located on the coast, and standing body of sea water could play a great role. It is thought that the now emergent part of the tuff cone was costructed subaerially because there is no evidence of marine reworking. The emergent tuff cone is characterized by distinctive steam-explosivity that results primarily from a bulk interaction between rapidly ascending magma and external water. The sea water gets into the vent by flooding accross or through the top or breach of northern tephra cone. Dangsanbong tuff cone was constructed from Surtseyan eruption which went into with tephra finger jetting explosion in the early stage, late interspersed with continuous upruch activities, and from ultra-Surtseyan jetting explosions producting base surges in the last. When the enclosure of the vent by a long-lived tephra barrier would prevent the flooding and thus allow the vent to dry out, the phreatomagmatic activities ceased to transmit into magmatic activity of Strombolian eruption, which constructed a cinder cone on the crater floor of the tuff cone Strombolian eruption ceased when magma in the conduit gradually became depleted in gas. In the Dangsanbong volcano, the last magmatic activity was Hawaiian eruption which went into with foundation and effusion of basalt lava.

• The KIPS Transactions:PartD
• /
• v.15D no.1
• /
• pp.61-72
• /
• 2008

One of the most significant tasks of software development project is to know how much it will be the software development cost in the early stage of software development cycle. The software development environment and technology are changing very rapidly. For accuracy, we should apply those to the software cost estimation. And it is important that we select the suitable adjustment factor and the value of a suitable adjustment factor. For that, this paper have applied the method of AHP. And we have also analyzed the sensitivity of the adjustment factor which is influenced by decision metrics. In conclusion, the value of the application type adjustment factor is responded more sensitively to the data complexity and the control complexity than processing complexity. And the value of the language adjustment factor is responded more sensitively to the supplying manpower and the time of the coding than the time of the debugging. In the future, we will research the selection of an additional adjustment factor and a suitable value of the adjustment factor which are influenced by the environment and the technology of the domestic software development. And then, in the language adjustment factor, we will try to calculate the value about the individual programming language.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.1
• /
• pp.109-115
• /
• 2019

In arc-welding applying to the present automobile part manufacturing process, a wrist-hollow type arc welding robot can shorten the welding cycle time, because feedability of a welding wire is not affected by a robot posture and thus facilitates high-quality arc welding, based on stable feeding with no entanglement. In this paper, we will propose the optimization of wrist design for a wrist-hollow type 6-Axis articulated robot. Specifically, we will perform the investigation on the optimized design of inner diameter of hollow arms (Axis 4 and Axis 6) and width of the upper arm by using the simulation of robot motion characteristics, using a Genetic Algorithm (i.e., GA). Our simulations are based on $SolidWorks^{(R)}$ for robot modeling, $MATLAB^{(R)}$ for GA optimization, and $RecurDyn^{(R)}$ for analyzing dynamic characteristics of a robot. Especially $RecurDyn^{(R)}$ is incorporated in the GA module of $MATLAB^{(R)}$ for the optimization process. The results of the simulations will be verified by using $RecurDyn^{(R)}$ to show that the driving torque of each axis of the writs-hollow 6-axis robot with the optimized wrist design should be smaller than the rated output torque of each joint servomotor. Our paper will be a guide for improving the wrist-hollow design by optimizing the wrist shape at a detail design stage when the driving torque of each joint for the wrist-hollow 6-axis robot (to being developed) is not matched with the servomotor specifications.

• Journal of the Korean Electrochemical Society
• /
• v.26 no.1
• /
• pp.11-18
• /
• 2023

As the use of lithium-ion secondary batteries is rapidly increasing due to the rapid growth of the electric vehicle market, the disposal and recycling of spent batteries after use has been raised as a serious problem. Since stored energy must be removed in order to recycle the spent batteries, an effective discharging process is required. In this study, graphite and NCM622 were used as active materials to manufacture coin-type half cells and full cells, and the electrochemical behavior occurring during overdischarge was analyzed. When the positive and negative electrodes are overdischarged respectively using a half-cell, a conversion reaction in which transition metal oxide is reduced to metal occurs first in the positive electrode, and a side reaction in which Cu, the current collector, is corroded following decomposition of the SEI film occurs in the negative electrode. In addition, a side reaction during overdischarge is difficult to occur because a large polarization at the initial stage is required. When the full cell is overdischarged, the cell reaches 0 V and the overdischarge ends with almost no side reaction due to this large polarization. However, if the full cell whose capacity is degraded due to the cycle is overdischarged, corrosion of the Cu current collector occurs in the negative electrode. Therefore, cycled cell requires an appropriate treatment process because its electrochemical behavior during overdischarge is different from that of a fresh cell.

• KIPS Transactions on Computer and Communication Systems
• /
• v.11 no.6
• /
• pp.193-204
• /
• 2022

In a smart factory environment in a small and medium-sized enterprise (SME) environment, sensors and actuators operating on actual manufacturing lines, programmable logic controllers (PLCs) to manage them, human-machine interface (HMI) to control and manage such PLCs, and consists of operational technology server to manage PLCs and HMI again. PLC and HMI, which are in charge of control automation, perform direct connection with OT servers, application systems for factory operation, robots for on-site automation, and production facilities, so the development of security technology in a smart factory environment is demanded. However, smart factories in the SME environment are often composed of systems that used to operate in closed environments in the past, so there exist a vulnerable part to security in the current environment where they operate in conjunction with the outside through the Internet. In order to achieve the internalization of smart factory security in this SME environment, it is necessary to establish a process according to the IEC 62443-4-1 Secure Product Development Life cycle at the stage of smart factory SW and HW development. In addition, it is necessary to introduce a suitable development methodology that considers IEC 62443-4-2 Component security requirements and IEC 62443-3 System security requirements. Therefore, this paper proposes an application plan for the IEC 62443 based development security process to provide security internalization to smart factories in an SME environment.

• Clinical and Experimental Reproductive Medicine
• /
• v.37 no.2
• /
• pp.143-151
• /
• 2010

Objective: The aim of this study was to compare day 3 embryo transfer (D3ET) with day 5 ET (D5ET) in fresh in vitro fertilization (IVF) cycle on pregnancy outcomes. Methods: We conducted a retrospective matched case control study that included 90 women with D3ET and 90 women with D5ET from January 2007 to June 2009. Subjects were matched for reproductive profiles and IVF cycle characteristics. Two good quality embryos were transferred in both groups. Pregnancy rates (PR), implantation rate, and multiple PR were compared. Results: Demographics, stimulation parameters and embryological data were comparable in both groups. Main pregnancy outcomes with D3ET and D5ET groups were not statistically different: implantation rate (39.4% vs. 32.8%), positive PR (57.8% vs. 46.7%), clinical PR (53.3% vs. 45.6%), ongoing PR (50.0% vs. 42.2%), respectively. Both groups showed high multiple PR (37.5% vs. 34.1). Conclusion: D5ET may not be beneficial and necessary in comparison with D3ET on pregnancy outcomes, and elective single ET should be considered to decrease multiple pregnancies in women with favorable conditions and good quality embryos undergoing IVF.

• Clinical and Experimental Reproductive Medicine
• /
• v.37 no.1
• /
• pp.65-72
• /
• 2010

Objective: To compare the respective pregnancy outcomes of cycles undergoing elective two cleavage-stage embryos transfer (2ET) and three cleavage-stage embryos transfer (3ET) in fresh in vitro fertilization and embryo transfer (IVF-ET) program. Methods: We conducted a retrospective matched case control study that included 100 women with 2ET and 100 women with 3ET from January 2007 to June 2009. Subjects were matched for reproductive profiles and cycle characteristics. All of transferred embryos in both groups had good qualities. Pregnancy rates (PR), implantation rate, and multiple PR were compared. Results: Demographics, stimulation parameters and embryological data were comparable in both groups. Main pregnancy outcomes with 2ET and 3ET groups were not statistically different; implantation rate (41.0% vs. 35.3%), positive pregnancy rate (58.0% vs. 60.0%), clinical PR (55.0% vs. 59.0%), ongoing PR (51.0% vs. 55.0%), respectively. However, the 3ET group showed significantly higher multiple pregnancy and triplet pregnancy rates (30.9% vs. 50.8%, p=0.031; 1.8% vs. 11.9%, p=0.036, respectively). Conclusion: In women with favorable conditions and good quality embryos undergoing IVF, 2ET can get pregnancy outcomes comparable to those of 3ET and reduce multiple pregnancy (especially, triplet pregnancy).

• Journal of Aquaculture
• /
• v.5 no.1
• /
• pp.29-67
• /
• 1992

Life cycle and seed production of the freshwater prawn, Macrobrachium nipponense, were studied and the results are as follows : 1. Larval development : Embryos hatched out as zoea larvae of 2.06 mm in mean body length. The larvae passed through 9 zoea stages in $15{\~}20$ days and then metamorphosed into postlarvae measuring 5.68 mm in mean body length. Each zoea stage can be identified based on the shapes of the first and second antennae, exo- and endopodites of the first and second pereiopods, telson and maxillae. 2. Environmental requirements of zoea larvae : Zoea larvae grew healthy when fed with Artemia nauplii. Metamorphosing rate was $65{\~}72{\%}$ at $26{\~}28\%$ and $7.85{\~}8.28\%_{\circ}Cl.$. The relationship between the zoeal period (Y in days) and water temperature (X in $^{\circ}C$) is expressed as Y=46.0900-0.9673X. Zoeas showed best survival in a water temperature range of $26{\~}32^{\circ}C$ (optimum temperature $28^{\circ}C$), at which the metamorphosing rate into postlarvae was $54{\~}72\%$ The zoeas survived more successfully in chlorinity range of $4.12{\~}14.08{\%_{\circ}}Cl.$, (optimum chlorinity $7.6{\~}11.6\;{\%_{\circ}}Cl.$.), at which the metamorphosing rate was $42{\~}76{\%}$. The whole zoeal stages tended to be longer in proportion as the chlorinity deviated from the optimum range and particularly toward high chlorinity. Zoeas at all stages could not tolerate in the freshwater. 3. Environmental requirements of postlarvae and juveniles : Postlarvae showed normal growth at water temperatures between $24{\~}32^{\circ}C$ (optimun temperature $26{\~}28^{\circ}$. The survival rate up to the juvenile stage was $41{\~}63{\%}$. Water temperatures below $24^{\circ}C$ and above $32^{\circ}$ resulted in lower growth, and postlarvae scarcely grew at below $17^{\circ}C$. Cannibalism tended to occur more frequently under optimum range of temperatures. The range of chlorinity for normal growth of postlarvae and juveniles was from 0.00 (freshwater) to $11.24{\%_{\circ}}Cl.$, at which the survival rate was $32{\~}35\%$. The postlarvae grew more successfully in low chlorinities, and the best growth was found at $0.00\~2.21{\%_{\circ}}Cl.$. The postlarvae and juveniles showed better growth in freshwater but did not survive in normal sea water. 4. Feeding effect of diet on zoea Ilarvae : Zoea larvae were successfully survived and metamorposed into postlarvae when fed commercial artificial plankton, rotifers, and Artemia nauplii in the aquaria. However, the zoea larvae that were fed Artemia nauplii and reared in Chlorella mixed green water showed better results. The rate of metamorphosis was $68\~{\%}75$. The larvae fed cow live powder, egg powder, and Chlorella alone did not survive. 5. Diets of postlarvae, juveniles and adults : Artemia nauplii and/or copepods were good food for postlarvae. Juveniles and adults were successfully fed fish or shellfish flesh, annelids, corn grain, pelleted feed along with viscera of domestic animals or fruits. 6. Growth of postlarvae, juveniles and adults : Under favorable conditions, postlarvae molted every five or six days and attained to the juvenile stage within two months and they reached 1.78 cm in body length and 0.17 g in body weight. The juveniles grew to 3.52 cm in body length and 1.07 g in body weight in about four months. Their sexes became determinable based on the appearance of male's rudimental processes (a secondary sex character) on the endopodites of second pereiopods of males. The males commonly reached sexual maturity in seven months after attaining the postlarvae stage and they grew to 5.65 cm in body length and 3.41 g in body weight. Whereas the females attained sexual maturity within six to seven months, when they measured 4.93 cm in body length and 2.43 g in body weight. Nine or ten months after hatching, the males grew $6.62{\~}7.14$ cm in body length and $6.68{\~}8.36$ g in body weight, while females became $5.58{\~}6.08$ cm and $4.04{\~}5.54$ g. 7. Stocking density : The maximum stocking density in aquaria for successful survival and growth was $60{\~}100$ individuals/$\ell$ for zoeas in 30-days rearing (survival rate to postlarvae, $73{\~}80{\%}$) ; $100{\~}300$ individuals/$m^2$ for postlarvae of 0.57 cm in body length (survival rate for 120 days, $78{\~}85{\%}$) ; $40{\~}60$ individuals/$m^2$ for juveniles of 2.72 cm in body length (survival rate for 120 days, $63{\~}90{\%}$) : $20{\~}40$ individuals/$m^2$ for young prawns of 5.2 cm in body length (survival rate for 120 days, $62\~90{\%}$) ; and $10\~30$ individuals/$m^2$ for adults of 6.1 cm in body length (survival rate for 60 days, $73\~100{\%}$). The stocking density of juveniles, youngs and adults could be increased up to twice by providing shelters.

• Journal of Sericultural and Entomological Science
• /
• v.52 no.2
• /
• pp.110-116
• /
• 2014

Recently the number of the butterflies, Mellicta ambigua, had been decreasing rapidly, and already disappeared at many habitat. In this studies, we investigated ecological environment of Mellicta ambigua for preparing of primary research data recovering habitat, and studied on bionomical characteristics. Two different habitat, Jindo and Inje, were selected for investigation of ecological environment. We investigated four times during 3-month, from June to August in 2012. In Jindo, we observed more than 100 butterflies and a lot of host plants, Melampyrum roseum var. japonicum. But only 5 butterflies and only a few host plants, Veronicastrum sibiricum were observed in Inje. We could not observe the eggs, the larva and pupa on the host plants at all. For finding of bionomical characteritics, we reared butterflies at natural conditions. Collected 3-female butterflies from Jindo laid 465 eggs on the leaves of 3-host plants, Veronicastrum sibiricum. 120 ~ 186 eggs per each female were laid in the shape of cluster. An egg was globular shape, 0.6 mm diameter and 0.7 mm height. The egg periods were $9.96{\pm}0.4days$ after ovipositioning, and the hatchability was 95.% at natural condition. The larval periods were $4.1{\pm}0.6days$ (1st instar), $2.1{\pm}1.0days$ (2nd), $8.1{\pm}0.7days$ (3rd), $239.2{\pm}10.9days$ (4th), $12.3{\pm}1.3days$ (5th), $17.1{\pm}1.1days$ (6th), $10.5{\pm}1.0days$ (7th) each other. The larva of 4th instar overwintered in the nest that had been made into the leaf of host plant with secreted thread as a group until early March next year. In the early March next year, overwintered larva went around their nest in search of host plants, and went to other host plants, Veronica persica and Plantago asiatica, sometimes. The overwintered larva of Mellicta ambigua could grow up on two other host plants normally. In the following experiment, the butterflies of Mellicta ambigua laid eggs on the leaves of Plantago asiatica, but the 1st instar larva from eggs died all. The headwidth of each developmental larval stage were $0.28{\pm}0.02mm$ (1st), $0.45{\pm}0.02mm$ (2nd), $0.58{\pm}0.02mm$ (3rd), $0.75{\pm}0.03mm$ (4th), $0.89{\pm}0.05mm$ (5th), $1.23{\pm}0.06mm$ (6th), $2.13{\pm}0.11mm$ (7th). The pupal ratio was 92.0%. The pupal period were $9.1{\pm}1.6days$, and the emergence rate was 88.6%. As a result we determined that Mellicta ambigua can rear at natural conditions. But indoor-rearing is considered to be difficult and not useful industrially, because they have long term larval stage and only one life cycle per an year.

• Korean Journal of Animal Reproduction
• /
• v.23 no.2
• /
• pp.105-111
• /
• 1999

The effects of exogenous spleen cells on the progesterone and insulin like-growth factor-I (IGF-I) secretions in luteal cells were studied by using in vitro luteal cell culture system in the Hanwoo luteal cells. The corpora lutea(CL) were collected and pooled from the Korean native cattle(Hanwoo) ovaries from a local slaughter house. After enzymatic dissociation, combined large and small luteal cells(LLC and SLC)(1.0$\times$10$^{6}$ cells/$m\ell$) were incubated in D-MEM media containing antibiotics and 10% FCS. Spleen cells (1.0$\times$10$^{6}$ cells/$m\ell$) obtained from castrated adult male Hanwoo were added to luteal cells and co-cultured for 24 h in the absence or presence of luteinizing hormone (LH) (100 ng). Progesterone contents from luteal tissues were increased at CL-3 stage during each stage of estrous cycle. Progesterone secretion from luteal cell culture by the presence of LH (100 ng/$m\ell$) was positively stimulated compared with control. However, progesterone secretion was not changed by the addition of 5, 10 and 20% of spleen cells in the absence of LH. Co-culture of luteal cells with 10% of spleen cells in the presence of LH(l00ng/$m\ell$) significantly. enhanced after 24 h of culture. IGF-Isecretion from in vitro luteal cells co-culture by the addition of spleen cells (5%, 10% and 20%) was not significantly effected. Besides, in the presence of LH (100ng/$m\ell$), IGF-Isecretions from luteal cells by addition of spleen cells were higher than control media. However, LH alone significantly increased IGF-I secretion at 24 h of culture. These data provide the demonstrate that spleen cells can enhance LH action so as to stimulate progesterone secretion from Hanwoo luteal cells but have no effect to stimulate IGF-I secretion.