• Journal of Korean Association for Spatial Structures
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• v.23 no.2
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• pp.19-28
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• 2023

Timber structures are susceptible to moisture, contamination, and pest infestation, which can compromise their integrity and pose a significant fire hazard. Despite these drawbacks, timber's lightweight properties, eco-friendliness, and alignment with current architectural trends emphasizing sustainability make it an attractive option for construction. Moreover, timber structures offer economic benefits and provide a natural aesthetic that regulates building temperature and humidity. In recent years, timber domes have gained popularity due to their high recyclability, lightness, and improved fire resistance. Researchers are exploring hybrid timber and steel domes to enhance stability and rigidity. However, shallow dome structures still face challenges related to structural instability. This study investigates stability problems associated with timber domes, the behavior of timber and steel hybrid domes, and the impact of timber member positioning on dome stability and critical load levels. The paper analyzes unstable buckling in single-layer lattice domes using an incremental analysis method. The critical buckling load of the domes is examined based on the arrangement of timber members in the inclined and horizontal directions. The analysis shows that nodal snapping is observed in the case of a concentrated load, whereas snap-back is also observed in the case of a uniform load. Furthermore, the use of inclined timber and horizontal steel members in the lattice dome design provides adequate stability.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.7
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• pp.530-532
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• 1999

A new lateral device entitled SB-DCEST(segmented p-base dual-channel emitter switched thyristor), which suppresses the snapback is proposed and successfully fabricated. The proposed device effectively suppressed the snapback phenomenon by employing the gigh resistance in self-aligned segmented p-base when compared with the conventional DCEST. The experimental results show that the SB-DCEST has the low forward voltage drop of 4.3 V at anode current of $150 A/cm^2$ with the eliminated snap-back regime, while conventional DCEST exhibits higher forward voltage drop of 5.3 V.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.2
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• pp.57-59
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• 2001

We investigated the maximum controllable current characteristics of the CB-BRT (Corrugated p-Base-Base Resistance Controlled Thyristor), which suppresses the snap-back effectively and increases the maximum controllable current(MCC) by employing the corrugated p-base. Experimental result shows that, when compared with conventional BRT, the MCC of the CB-BRT exhibits good stability on various process parameters. The MCC of the CB-BRT is larger than that of the conventional BRT by 50%, and the variation of the MCC in CB-BRT, caused by variation of the process parameters, is only 20% of that of the conventional BRT.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.3
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• pp.183-189
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• 2010

In this paper, the trench gate emitter switched thyristor(EST) withl trench gate electrode is proposed for improving snap-back effect which leads to a lot of problems in device applications. The parasitic thyristor which is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The dual trench gate allows homogenous current distribution in the EST and preserves the unique feature of the gate controlled current saturation of the thyristor current. The characteristics of the 1700 V forward blocking EST obtained from two-dimensional numerical simulations (MEDICI) is described and compared with that of a conventional EST. we carried out layout, design and process of EST devices.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.3
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• pp.167-172
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• 1999

The device characteristics of the base resistance controlled thyristor with self-align corrugated p-base is demonstrated for the first time with varying the n+ cathode width and the temperature form room temperature to $125^{\circ}C$. The experimental results show that the snap-back in the CB-BRT is significantly suppressed irrespective of the various n+ cathode width and the temperature as compared with that of the conventional BRT. The maximum controllable current of the CB-BRT is uniformly higher when compared with that of the conventional BRT over the temperature range from room temperature to $125^{\circ}C$.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.2
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• pp.113-115
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• 2000

The gradual hole injection LIGBT (GI-LIGBT) which employs the dual gate and the p+ injector, was fabricated for eliminating a negative resistance regime and reducing a forward voltage drop in SA-LIGBT. The elimination of the negative resistance regime is successfully achieved by initiating the hole injection gradually. Furthermore, the experimental results show that the forward voltage drop of GI-LIGBT decreases by lV at the current density of 200 $A/cm^2$, when compared with that of the conventional SA-LIGBT. It is also found that the improvement in the on-state characteristics can be obtained without sacrificing the inherent fast switching characteristics of SA-LIGBT.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.9
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• pp.736-742
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• 1991

N$^{+}$poly gate NMOSFETs and p$^{+}$ poly gate (surface type) PMOSFETs with three different gate oxides(SiO2, NO, and ONO) were fabricated. The rapid thermal nitridation and reoxidation techniques have been applied to gate oxide formation. The current drivability of the ONO NMOSFET shows larger values than that of the SiO2 NMOSFET. The snap-back occurs at a lower drain voltage for SiO$_2$ cases for ONO NMOSFET. Under the maximum substrate current bias conditions, hot-carrier effects inducting threshold voltage shift and transconductance degradation were investigated. The results indicate that ONO films exhibit less degradation in terms of threshold voltage shift. It was confirmed that the ONO samples achieve good improvement of hot-carrier immunity. In a SiO$_2$ SC-PMOSFET, with significant boron penetration, it becomes a depletion type (normally-on). But ONO films show excellent impurity barrier properties to boron penetration from the gate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.8
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• pp.587-595
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• 1998

Transient thermal analysis simulations are carried out using a modeling program to understand the human body model HBM ESD. The devices were simulated a one-dimensional device subjected to ESD stress by solving Poison's equation, the continuity equation, and heat flow equation. A ramp rise with peak ESD voltage during rise time is applied to the device under test and then discharged exponentially through the device. LDD and NMOS structures were studied to evaluate ESD performance, snap back voltages, device heating. Junction heating results in the necessity for increased electron concentration in the space charge region to carry the current by the ESD HBM circuit. The doping profile adihacent to junction determines the amount of charge density and magnitude of the electric field, potential drop, and device heating. Shallow slopes of LDD tend to collect the negative charge and higher potential drops and device heating.

• Fashion & Textile Research Journal
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• v.13 no.1
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• pp.17-24
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• 2011

This study aims to provide basic materials for adaptive-clothing development for disabled seniors by considering the characteristics of design with both functionality and beauty, which is displayed to overseas functional clothing for disabled seniors. After 341 photographs from 15 overseas websites which sold adaptive-clothing for disabled seniors were collected, their designs were analyzed. The content analysis and frequency analysis using the descriptive statistics were performed as the analytical methods for this study. The results are as follows; first, the design of buttons uses snap fasteners, zippers, Velcro fasteners and rubber bands so as to attach easily and keep fasteners unseen. Second, the used open system is the Back open, the Side open, the Front open and the Hip open. Third, in terms of design, the change follows easy and loose silhouette in order to act comfortably outdoors as well as indoors by making the design of onepiece dresses, jackets and cardigans similar to ordinaries. From the details aspect, a few trimmings such as color, patterns, ruffles around edge, laces and smooth shirring do not stand in the way and give mental please.

• Journal of the Korean Society of Costume
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• v.61 no.7
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• pp.67-79
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• 2011

This study is to design a ball-jointed doll costume with historical research in clay female doll's costume from Hwangsung-dong tomb of the Silla Dynasty[新羅] in 7C. This clay female doll's costume was characterized by slim silhouette, long sleeves, no neckline, side slit, high waistline, and bun on the back neck of representative of the early era. According to literature of 7-8C and textile relics, it is presumed that she wore short Jeogori[短衣, Dan-eui] with long sleeves and two layered skirt, and Dan-ryeong(團領) could be added as attachment that is reflective of the time era. For making design costume, Ra[羅, silk gauze] was used for long Dan-ryeong, plain silk and brocade[錦, Geum] for Dan-eui and skirt as a special textile of this period. Waist dart and small snap were added to the costume of ball-jointed doll because of hardness and curvy shape of doll's body, without contradicting traditional value. For better use of this study and cost reduction purposes, development of production system for traditional doll costumes should be considered.