• Geomechanics and Engineering
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• v.37 no.3
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• pp.293-306
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• 2024

Influenced by the alternating effects of dynamic and static pressure during the mining process of close range coal seams, the surrounding rock support of cross mining roadway is difficult and the deformation mechanism is complex, which has become an important problem affecting the safe and efficient production of coal mines. The paper takes the inclined longwall mining of the 10304 working face of Zhongheng coal mine as the engineering background, analyzes the key strata fracture mechanism of the large inclined right-angle trapezoidal mining field, explores the stress distribution characteristics and transmission law of the surrounding rock of the roadway affected by the mining of the inclined coal seam, and proposes a segmented and hierarchical support method for the cross mining roadway affected by the mining of the close range coal seam group. The research results indicate that based on the derived expressions for shear and tensile fracture of key strata, the ultimate pushing distance and ultimate suspended area of a right angle trapezoidal mining area can be calculated and obtained. Within the cross mining section, along the horizontal direction of the coal wall of the working face, the peak shear stress is located near the middle of the boundary. The cracks on the floor of the cross mining roadway gradually develop in an elliptical funnel shape from the shallow to the deep. The dual coupling support system composed of active anchor rod support and passive U-shaped steel shed support proposed in this article achieves effective control of the stability of cross mining roadways, which achieves effective control of floor by coupling active support and preventive passive support to improve the strength of the surrounding rock itself. The research results are of great significance for guiding the layout, support control, and safe mining of cross mining roadways, and to some extent, can further enrich and improve the relevant theories of roof movement and control.

• Journal of Powder Materials
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• v.13 no.5 s.58
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• pp.327-335
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• 2006

In the development of new hydrogen absorbing materials for a next generation of metal hydride electrodes for rechargeable batteries, metastable Mg-Ni-based compounds find currently special attention. Amor phous-nanocrystalline $Mg_{63}Ni_{30}Y_7$ and $Mg_{50}Ni_{30}Y_{20}$ alloys were produced by mechanical alloying and melt-spinning and characterized by means of XRD, TEM and DSC. On basis of mechanically alloyed Mg-Ni-Y powders, complex hydride electrodes were fabricated and their electrochemical behaviour in 6M KOH (pH=14,8) was investigated. The electrodes made from $Mg_{63}Ni_{30}Y_7$ powders, which were prepared under use of a SPEX shaker mill, with a major fraction of nanocrystalline phase reveal a higher electrochemical activity far hydrogen reduction and a higher maximum discharge capacity (247 mAh/g) than the electrodes from alloy powder with predominantly amorphous microstructure (216 mAh/g) obtained when using a Retsch planetary ball mill at low temperatures. Those discharge capacities are higher that those fur nanocrystalline $Mg_2Ni$ electrodes. However, the cyclic stability of those alloy powder electrodes was low. Therefore, fundamental stability studies were performed on $Mg_{63}Ni_{30}Y_7$ and $Mg_{50}Ni_{30}Y_{20}$ ribbon samples in the as-quenched state and after cathodic hydrogen charging by means of anodic and cathodic polarisation measurements. Gradual oxidation and dissolution of nickel governs the anodic behaviour before a passive state is attained. A stabilizing effect of higher fractions of yttrium in the alloy on the passivation was detected. During the cathodic hydrogen charging process the alloys exhibit a change in the surface state chemistry, i.e. an enrichment of nickel-species, causing preferential oxidation and dissolution during subsequent anodization. The effect of chemical pre-treatments in 1% HF and in $10\;mg/l\;YCl_3/1%\;H_2O_2$ solution on the surface degradation processes was investigated. A HF treatment can improve their anodic passivation behavior by inhibiting a preferential nickel oxidation-dissolution at low polarisation, whereas a $YCl_3/H_2O_2$ treatment has the opposite effect. Both pre-treatment methods lead to an enhancement of cathodically induced surface degradation processes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.6
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• pp.569-576
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• 2012

In general, aluminum alloys forms the passive film($Al_2O_3$, $Al_2O_3{\cdot}3H_2O$) in neutral solution. However, the passive film created on the surface will be destroyed by chloride ions contained in sea water so the corrosion will occur. In this study, in order to solve the problem of corrosion under a seawater environment, potentiostatic protection techniques were applied to Al-4.5%Mg-0.6%Mn aluminum alloy in seawater. At polarization experiments, active state were observed at anodic polarization and concentration polarization by reduction of dissolves oxygen and activation polarization were found at anodic polarization. As a results of potentiostatic experiment, calcareous deposit were created much more as applying time increase from the turning point of the concentration polarization and activation polarization and crevice corrosion was partially observed between calcareous deposit and surface of base metal. Overall potentiostatic anodic polarization experiment was difficult to apply potentiostatic corrosion protection technology by occurrence of active state, whereas potentiostatic cathodic polarization experiment examined optimum corrosion protection condition of -1.1 V~-0.75 V within the range of concentration polarization considered various applying time.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.2
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• pp.141-150
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• 2001

Manufacturing conb'ol applications consist of concurrent active components such as robots, AGV's (Automatic Guided Vehicles), and conveyors. Running of manufacturing control programs is interactions among those components. We can enhance the productivity and extendability of manufacturing control applications by using the object-oriented teclmology that models those components as reusable objects. But the objects in current object-oriented technology that encapsulate state and behavior infonnation are passive in a sense that those respond only when messages are sent to them. In this paper, we introduce the Distributed Active Object Systems (DAGS) approach that SUPPOltS active objects. Since active objects encapsulate control infonnation in addition to state and behavior information under COREA/Java-based distributed environment, they can represent manufacturing control components better than the objects in ordimuy object-oriented technology. TIus control infonnation provides an object with a featme that can monitor its own status as well as other object's status connected by intelface valiables. Active objects can initiate a behavior according to the change of those status. Therefore, we can sb-uctmally assemble self-initiating active objects by using intelface variables to construct a system without describing bow to control distributed objects by using message passing. As the DAOS approach supports object composability, we can enhal1ce the productivity and extendability of disbibuted manufactming control applications even better than the ordil1alY object-oriented approach. Also, the DAOS approach supports better component reusability with active objects that encapsulate control information .

• Fashion & Textile Research Journal
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• v.6 no.1
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• pp.32-40
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• 2004

This study is done to assist in the limit of stage dress design research considering the sense of the times and the sympathy of spectators for actual stage. For the base research, to visualize the image which the spectators are feeling from Shakespeare's Hamlet, the evaluators had to analyze the whole image and color tone of the figures. First of all, 2 clothing for Hamlet, Gertrude and Ophelia had to be designed, and following conclusion has drawn. Hamlet A corresponds with passive looks which is a combination of loneliness, sadness and the unstable mental state of not adapting to and hiding from the reality. Hamlet B has more of matured looks which make Hamlet more free and comfortable from life and death as he overcame a crisis of death. Gertrude A corresponds with the image of coming right out of the funeral of late king. Gertrude B shows more of her sadness as she hears of her son Hamlet's despair and resentment and her maternal return degradation which is a special situations emphasizing her unstable and dizzy image. Ophelia A shows her usual and normal looks of a livelihood and femininity. She congratulates the wedding and coronation, and falls in love with Hamlet which shows a lot of her girlish image. Ophelia B shows dismantled rationality and violated virginity which is a very complex and unstable state showing a completely different image. Based on the above research. It was proposed their clothing through the next study of the characters, and personally make them for 2003 Yeonheedan Street Group's performance Hamlet.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.358-370
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• 2017

This thesis discusses the emerging system of value and structure of feeling in today's Chinese society through analyzing Chinese main theme TV series. The 2000s' Chinese main theme TV series represents Chinese's anger and nervousness into the structure of narrative, and they try to form a bond of sympathy with the audience by various characters which represent the common people. Main characters are no longer revolutionists who internalize ideas of socialism and collectivism, but they put emphasis on individuals' thoughts, tastes, and values, and freely express them. Individualism, which was negatively represented and excluded in main theme TV series before 2000s, are compromised and included in today's Chinese dramas. Even though dramas represent the superiority of communism, individuals' choice of various value and faith is positively and flexibly considered. There is a new phenomenon where female figures are no longer passive and dependent, but they are portrayed with given with unique roles and status. Although main theme TV series are directed under the state and government's supervision, they exist in the relation where market, state, drama text, and audience interact.

• KIEE International Transactions on Power Engineering
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• v.3A no.1
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• pp.27-34
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• 2003

In this paper, the power conditioner composed of the stand-alone single-phase squirrel cage rotor type self-excited induction generator (SEIG) driven by prime movers such as a wind turbine and a micro gas turbine (MGT) is presented by using the steady-state circuit analysis based on the two nodal admittance approaches using the per-unit frequency in addition to a new state variable defined by the per-unit slip frequency along with its performance evaluations for the stand-alone energy utilizations. The stande-alone single-phase SEIG operating performances in unregulated voltage control loop are then evaluated on line under the conditions of the speed change transients of the prime mover and the stand-alone electrical passive load power variations with the simple theoretical analysis and the efficient computation processing procedures described in the part I of this paper. In addition, a feasuible PI controlled feedback closed-loop voltage regulation scheme of the stande-alone single-phase SEIG is designed on the basis of the static VAR compensate. (SVC) and discussed in experiment for the promising stand-alone power conditioner. The experimental operating performance results are illustrated and give good agreements with the simulation ones. The simulation and experimental results of the stand-alone single-phase SEIG with the simple SVC controller for its stabilized voltage regulation prove the practical effectiveness of the additional SVC control loop scheme including the PI controller with fast response characteristics and steady-sate performance improvements.

• Corrosion Science and Technology
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• v.6 no.6
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• pp.291-296
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• 2007

The corrosion of metals and alloys in flowing liquids can be classified into uniform corrosion and localized corrosion which may be categorized as follows. (1) Localized corrosion of the erosion-corrosion type: the protective oxide layer is assumed to be removed from the metal surface by shear stress or turbulence of the fluid flow. A macro-cell may be defined as a situation in which the bare surface is the macro-anode and the other surface covered with the oxide layer is the macro-cathode. (2) Localized corrosion of the differential flow-velocity corrosion type: at a location of lower fluid velocity, a thin and coarse oxide layer with poor protective qualities may be produced because of an insufficient supply of oxygen. A macro-cell may be defined as a situation in which this surface is the macro-anode and the other surface covered with a dense and stable oxide layer is the macro-cathode. (3) Localized corrosion of the active/passive-cell type: on a metal surface a macro-cell may be defined as a situation in which a part of it is in a passivation state and another in an active dissolution state. This situation may arise from differences in temperature as well as in the supply of the dissolved oxygen. Compared to uniform corrosion, localized corrosion tends to involve a higher wall thinning rate (corrosion rate) due to the macro-cell current as well as to the ratio of the surface area of the macro-anode to that of the macro-cathode, which may be rationalized using potential vs. current density diagrams. The three types of localized corrosion described above can be reproduced in a Jet-in-slit test by changing the flow direction of the test liquid and arranging environmental conditions in an appropriate manner.

• Tribology and Lubricants
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• v.31 no.3
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• pp.79-85
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• 2015

RC delay is a critical issue for achieving high performance of ULSI devices. In order to minimize the RC delay time, we uses the CMP process to introduce high-conductivity Cu and low-k materials on the damascene. The low-k materials are generally soft and fragile, resulting in structure collapse during the conventional high-pressure CMP process. One troubleshooting method is electrochemical mechanical polishing (ECMP) which has the advantages of high removal rate, and low polishing pressure, resulting in a well-polished surface because of high removal rate, low polishing pressure, and well-polished surface, due to the electrochemical acceleration of the copper dissolution. This study analyzes an electrochemical state (active, passive, transpassive state) on a potentiodynamic curve using a three-electrode cell consisting of a working electrode (WE), counter electrode (CE), and reference electrode (RE) in a potentiostat to verify an electrochemical removal mechanism. This study also tries to find optimum conditions for ECMP through experimentation. Furthermore, during the low-pressure ECMP process, we investigate the effect of current density on surface roughness and removal rate through anodic oxidation, dissolution, and reaction with a chelating agent. In addition, according to the Faraday’s law, as the current density increases, the amount of oxidized and dissolved copper increases. Finally, we confirm that the surface roughness improves with polishing time, and the current decreases in this process.

• Journal of Korea Game Society
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• v.14 no.6
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• pp.7-18
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• 2014

People generally think that negative effects of violent game contents are more serious in active playing behavior than passive watching video. This research examined the negative emotions which could arise out of playing violent games as fear, anxiety, hate, state-anger, hostility, and depression and performed an experiment methodology to assess those emotion effects between playing and watching violent game. The results of this research found that the watching group of violent video game showed a stronger internal negative feeling such as hate and depression, but the playing group of violent game had a deeper state-anger and hostility as external negative feeling than watching group. This research concludes that each media delivers different negative feelings, and there is little difference in the intensity of negative effects between playing and watching violent game.