• Journal of Astronomy and Space Sciences
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• v.25 no.2
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• pp.71-76
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• 2008

Study of terrestrial impact craters is important not only in the field of the solar system formation and evolution but also of the Galactic astronomy. The terrestrial impact cratering record recently has been examined, providing short- and intermediate-term periodicities, such as, ${\sim}26$ Myrs, ${\sim}37$ Myrs. The existence of such a periodicity has an implication in the Galactic dynamics, since the terrestrial impact cratering is usually interpreted as a result of the environmental variation during solar orbiting in the Galactic plane. The aim of this paper is to search for a long-term periodicity with a novel method since no attempt has been made so far in searching a long-term periodicity in this research field in spite of its great importance. We apply the cepstrum analysis method to the terrestrial impact cratering record for the first time. As a result of the analysis we have found noticeable peaks in the Fourier power spectrum appear ing at periods of ${\sim}300$ Myrs and ${\sim}100$ Myrs, which seem in a simple resonance with the revolution period of the Sun around the Galactic center. Finally we briefly discuss its implications and suggest theoretical study be pursued to explain such a long-term periodicity.

• Human Ecology Research
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• v.55 no.3
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• pp.303-319
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• 2017

This study explored the sandplay therapy case of a middle-aged woman having difficulty with interpersonal relationships and wanting to increase her self-identity. The goal of the therapy was to change her relationships with others by self-examination and becoming conscious of her negative animus and femininity in a free and protected space provided by sandplay therapy. Forty-five therapy sessions were held. The client exhibited her lonesomeness and fantasies by making sandtrays of a house she would like to live in, a park she would like to relax at and dreams she would like to fulfill in the initial phase of therapy (1~8, Who am I?). In the intermediate phase of therapy (9~33, Meeting myself), she displayed scenes of her negative self and breaking away from her negative self by making sandtrays of shadows, deaths, creations, a soaring scene and a disappearing alligator. In the final phase of therapy (34~45, Discovery of the real Self), she showed scenes of her meeting a positive self by making sandtrays of hope, coexistence, start, harmony and community. This study showed the effectiveness of sandplay therapy since the client' relationships with others were improved through her self-awareness by sandplay therapy in the free and protected space.

• ETRI Journal
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• v.30 no.6
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• pp.790-798
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• 2008

Recently, NAND flash memory has emerged as a next generation storage device because it has several advantages, such as low power consumption, shock resistance, and so on. However, it is necessary to use a flash translation layer (FTL) to intermediate between NAND flash memory and conventional file systems because of the unique hardware characteristics of flash memory. This paper proposes a new clustered FTL (CFTL) that uses clustered hash tables and a two-level software cache technique. The CFTL can anticipate consecutive addresses from the host because the clustered hash table uses the locality of reference in a large address space. It also adaptively switches logical addresses to physical addresses in the flash memory by using block mapping, page mapping, and a two-level software cache technique. Furthermore, anticipatory I/O management using continuity counters and a prefetch scheme enables fast address translation. Experimental results show that the proposed address translation mechanism for CFTL provides better performance in address translation and memory space usage than the well-known NAND FTL (NFTL) and adaptive FTL (AFTL).

• Journal of Families and Better Life
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• v.32 no.6
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• pp.1-18
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• 2014

This study explored the sandplay therapy case of a middle school-aged boy having severe conflicts with his mother, from the viewpoints of initiation. The goal of the therapy was to lessen the boy's conflicts with his mother within the free and protected space in sandplay therapy. Thirty-seven therapy sessions were held. The client showed the scene of having fun in the water in the most unconscious part of the tray in the initial phase of therapy (1, descending into the unconscious). In the intermediate phase of therapy (2~33, a period of suffering, confrontation with death and trials), he showed suffering, was confronted with death and underwent trials. In the final phase of therapy (34~37, seeking masculine principles and rebirth), he began to seek masculine principles instead of having conflicts with his mother and was reborn. Using sandplay therapy in a free and protected space, this study showed the effectiveness of sandplay therapy since the boy's severe conflicts with his mother were lessened. This study also confirmed the existence of an archetypal pattern in the male adolescent's psyche.

• International Journal of Aeronautical and Space Sciences
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• v.10 no.1
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• pp.67-74
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• 2009

In general, the lunar landing stage can be divided into two distinct phases: de-orbit and descent, and the descent phase usually comprises two sub-phases: braking and approach. And many optimization problems of minimal energy are usually focused on descent phases. In these approaches, the energy of de-orbit burning is not considered. Therefore, a possible low perilune altitude can be chosen to save fuel for the descent phase. Perilune altitude is typically specified between 10 and 15km because of the mountainous lunar terrain and possible guidance errors. However, it requires more de-orbit burning energy for the lower perilune altitude. Therefore, in this paper, the perilune altitude of the intermediate orbit is also considered with optimal thrust programming for minimal energy. Furthermore, the perilune altitude and optimal thrust programming can be expressed by a function of the radius of a parking orbit by using continuation method and co-state estimator.

• Journal of Astronomy and Space Sciences
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• v.11 no.1
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• pp.115-130
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• 1994

In the framework of Thomas-Fermi equation, we have examined the properties of neutron star by assuming the existence of a new intermediate force which is composition dependent. We have found that the structure, size and mass of neutron star are affected by the strength and range of this new force. In the ultrarelativistic limit, we have also confirmed that Chandraseknar mass, $M_{ch}\simeq(1-\alpha)^{-3/2}{m_{pl}}^3/m^2$ is determined by the constants of classical physical laws, which take part in the selfgravitating processes on neutron star as well as the constant of hypothetical fifth force. In the experimental limits of the fifth force, the changes of size and mass of a neutron star are in the order of strength parameter $\alpha$.

• Korean Journal of Child Studies
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• v.36 no.1
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• pp.19-45
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• 2015

This study explored the sandplay therapy case of an elementary school-aged girl living in a home in which there exist severe conflicts between her mother and older brother. This study focused heavily on fairy tales. The goal of the therapy was to encourage appropriate adjustments with the girl's situation within the free and protected space of sandplay therapy. Forty-four therapy sessions were held. The client exhibited evidence of feelings of being abandoned and of becoming lethargic in the initial phase of therapy (1~10, forsakenness/sleeping family). In the intermediate phase of therapy (11~38, regression, opposition and purification/growth), as she displayed signs of regression, princess play, the opposition of goodness and badness and purification, she grew psychologically. In the final phase of therapy (39~44, redemption/rebirth of new consciousness), she was redeemed and reborn with a new sense of consciousness. Using sandplay therapy in a free and protected space, this study showed the various motives of fairy tales in the psyche of a pre-adolescence girl and the effectiveness of sandplay therapy.

• Human Ecology Research
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• v.56 no.4
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• pp.331-345
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• 2018

This study explored the sandplay therapy case of a woman with a negative mother complex who wants to be free from family life. The goal of the therapy was to make her free from family life by expressing repressed emotions for getting out of a negative mother complex under a free and protected space in sandplay therapy. Twenty-three therapy sessions were held. The client exhibited a singing woman in a gorgeous dress and things she wanted to do in the initial phase of therapy (1-4, forgotten myself). In the intermediate phase of therapy (5-15, differentiation and integration), she displayed the scenes of differentiation and integration by emotionally getting rid of a begging boy and making mandalas. In the final phase of therapy (16-23, recovered myself), she showed scenes of rebirth, upgrading and singing songs again in front of family members and many people. Through sandplay therapy in the free and protected space, this study showed the effectiveness of sandplay therapy since the client achieved individuation by showing rebirth, having a new personality.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.514-517
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• 1996

In solving multi-level knapsack problems, conventional heuristic approaches often assume a short-sighted plan within a static decision enviornment to find a near optimal solution. These conventional approaches are inflexible, and lack the ability to adapt to different problem structures. This research approaches the problem from a totally different viewpoint, and a new method is designed and implemented. This method performs intelligent actions based on memories of historic data and learning. These actions are developed not only by observing the attributes of the optimal solution, the solution space, and its corresponding path to the optimal solution, but also by applying human intelligence, experience, and intuition with respect to the search strategies. The method intensifies, or diversifies the search process appropriately in time and space. In order to create a good neighborhood structure, this method uses two powerful choice rules that emphasize the impact of candidate variables on the current solution with respect to their profit contribution. A side effect of so-called "pseudo moves", similar to "aspirations", supports these choice rules during the evaluation process. For the purpose of visiting as many relevant points as possible, strategic oscillation between feasible and infeasible solutions around the boundary is applied for intensification. To avoid redundant moves, short-term (tabu-lists), intermediate-term (cycle detection), and long-term (recording frequency and significant solutions for diversification) memories are used. Test results show that among the 45 generated problems (these problems pose significant or insurmountable challenges to exact methods) the approach produces the optimal solutions in 39 cases.lutions in 39 cases.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.2
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• pp.17-25
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• 2003

In this paper, a processor architecture is proposed based on the state space implementation technique for real time processing of 2-D discrete wavelet transform(DWT). It conducts 2-D DWT operations in consideration of row and column direction simultaneously, thus can reduce latency due to memory access for storing intermediate results. It is a VLSI architecture suitable for real time processing. The proposed architecture includes only four multipliers and four adders, and NK-N internal memory storage, where K denotes the length of filter. It has a small hardware complexity. Therefore it is very suitable architecture for real time, embedded applications such as web camera server. Since the processor is easily extended to array structure, it can be applied to various image processing applications.