• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.281-299
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• 1995

The purpose of this study was to evaluate the degree of occlusal contact under the fixed implant prosthesis of partially edentulous patients which was hased on occlusal concept of implant prosthesis. From the patients who have free-standing implant supported prosthesis of unilateral partially edentulous area, occlusal and occlusal contact point of th enatural tooth side and implant side of light closure and heavy closure were analyzed by T-scan system throuht pre-and post-adjustment and the degree of occlusal contact was estimated by Shimstock. The following results were obtained : 1. The occlusal force of natural tooth side(NF) from mid-sagittal axis was relatively constant at light and heavy closure through pre-and post-adjustment, but the occlusal force of implant side(IF) was decreased significantly at light closure(P<0.01) and heavy closure(P<0.05) of post-adjustment. 2. Natural tooth side-implant side moment(MIMoment) fo occlusal force from mid-sagittal axis was significant(p<0.05) through pre-and post-adjustment and the deviation from mid-sagittal axis was increased at light closure of post-adjustment, but was decreased at heavy closure of post-adjustment. 3. Comparing the NF and IF, IF was greater at heavy closure of pre-adjustment, and NF was greater at light closure of post-adjustment, and the NF and IF was relatively equally distributed at light closure of pre-adjustment and at heavy closure of post-adjustment. 4. The number of occlusal contact point of natural tooth side(NC) was relatively constant through pre-and post-adjustment, but the number of occlusal contact point of implant side(IC) was significantly decreased(P<0.05) at light closure of post-adjustment, and was not significant but was lesser at heavy closure of post-adjustment. 5. Difference of the NC and IC was greater at light closure of post-adjustment, but it was less at heavy closure of post-adjustment, and therefore occlusal contact point of natural tooth side and implant side was relatively equally distributed at heavy closure of postadjustment. 6. When bilaterally distribution of occlusal force and occlusal contact point was established, degree of occlusal contact of implant suporoted prosthesis with opoosing teeth at light clousre was $34.13{\pm}21.69{\mu}m$.

• Speech Sciences
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• v.11 no.4
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• pp.223-232
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• 2004

This study investigated and compared the acoustic characteristics of the Korean stop sound [k'] in three different phonological environments: the tensified lenis stop [k'] as observed in /prek+kaci/, the fortis stop /k'/ as in /pre+k'aci/, and the fortis stop /k'/ following an obstruent as in /prek+k'aci/. The specific research question was whether or not the tensified lenis stop shares all the acoustic features with the other two kinds of fortis stops. The acoustic measures adopted in this study were H1*-H2*, VOT, length of stop closure, and $F_0$. The major findings were that the three stops showed no significant difference in all the acoustic measures except the length of stop closure. The fortis stop /k'/ following an obstruent showed significantly longer duration of stop closure than the other two stops, both of which showed no significant difference. Based on these phonetic results, this study argued that, for the proper phonological description of post-obstruent tensification, the phonological feature [slack vocal folds] of a lenis stop should be changed into [stiff vocal folds, constricted glottis] that the fortis stops should have.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.530-545
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• 2023

As an alternative to conventional management options for a lot of concrete waste from decommissioning of nuclear power plants, a set of scenarios for controlled recycling of decommissioning concrete waste as engineered barriers of a radioactive waste repository was proposed, and a comprehensive safety assessment model and framework covering both pre-and post-closure phases was newly developed. The new methodology was applied to a reference vault-type repository, and the ratios of derived concentration limits to unconditional clearance levels of eighteen radionuclides for controlled recycling were provided for three sets of dose criteria (0.01, 1, and 20 mSv/y for the pre-closure and 0.01 mSv/y for the post-closure phases). It turns out that decommissioning concrete waste whose concentration is much higher than the unconditional clearance level can be recycled even when the dose criterion 0.01 mSv/y is applied. Moreover, a case study on ABWR bio-shield shows that the fraction of recyclable concrete waste increases significantly by increasing the dose criterion for the radiation worker in the pre-closure phase or the duration of storage prior to recycling. The results of this study are expected to contribute to demonstrating the feasibility of controlled recycling of a lot of decommissioning concrete waste within nuclear sectors.

• Journal of Soil and Groundwater Environment
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• v.24 no.4
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• pp.11-19
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• 2019

This paper examines an assessment method for terminating the post-closure maintenance of a landfill using a simplified landfill gas model. The case study site is the Sudokwon Landfill in Incheon city, which was closed in 2000. The deviations of the results obtained by the regular model and the simplified model were both slightly over 10% from the measured data. Also, the deviation of the simplified model from the regular model has been less than 5% since 2005. Thus, the simplified model could be applied to other landfills that have been closed for at least 5 years. Additionally, the results of the mass balance analysis using the simplified landfill gas model indicated that 39% of the organic carbon was discharged, leading to organic carbon and organic matter content of 7.2 and 17.6%, respectively, in the landfill by the end of 2018.

• Speech Sciences
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• v.14 no.4
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• pp.25-39
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• 2007

The present study investigated some perceptual phonetic attributes of two Korean stop types, aspirated and lax, in medial position of an accentual phrase. The intonational pattern across syllables (Jun, 1993) is argued to depend on the type of stop (aspirated vs. lax) only in the initial position of an accentual phrase. In Kang & Dilley (2007), we showed that significant differences between aspirated and lax stops in medial position of an accentual phrase exist in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. In the present perception experiment, we investigated whether these phonetic attributes contribute to the perception of these two types of stops: The closure durations and/or F0's of post-stop vowels on accentual-phrase medial words were altered and twenty native Korean speakers then judged these words as beginning with an aspirated or lax stop. Both closure duration and F0 significantly affected judgments of stop identity. These results indicate that a wider range of acoustic cues that distinguish aspirated and lax Korean stops in production also plays a role in perception. To account for these results we suggest some phonetic and phonological models of consonant-tone interactions for Korean.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.79-83
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• 2010

As bolus enters the pharynx during the swallow, laryngeal closure takes place by approximating the epiglottis to the arytenoid Laryngeal Closure Duration(LCD) is the duration of contact between the arytenoids and the epiglottis from the first contact to the last(Logemann et al, 2000). Epiglottic inversion continues pharyngeal swallow stage is completed in order to protect the airway. The purpose of this study is to measure layrngeal closure duration (LCD) in three groups of subjects: a) 10 stroke patients who aspirate before and during the swallow(aspirators), b) 10 stroke patients who do not aspirate during the swallow c)10 normal control subjects. Means and standard deviation of LCD was analyzed in both 5ml and 10 ml thin liquids using 100msec timer in videoflouroscopic swallowing examination. The mean for each group was 0.15 seconds shorter from aspirators to control group. There was a significant difference between aspirators and normal subjects for laryngeal closure duration during the swallow. Laryngeal closure duration after a stroke lead to aspiration. However, only one of this temporal problem may not be enough to aspiration.

• Journal of Soil and Groundwater Environment
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• v.22 no.4
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• pp.33-48
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• 2017

An optimum disposal plan of disused sealed radioactive sources (DSRSs) should be established to ensure long-term disposal safety at the low- and intermediate-level radioactive waste (LILW) disposal facility in Gyeongju. In this study, an optimum disposal system was suggested and preliminary post-closure safety assessment was performed. The DSRSs disposal system was composed of a rock cavern and near surface disposal facilities at the Gyeongju LILW disposal facility. The assessment was conducted using GoldSim program, and probabilistic assessment and sensitivity analysis were implemented to evaluate the uncertainties in the input parameters of natural barriers. Deterministic and probabilistic calculations indicated that the maximum dose was below the regulatory limits ($0.1mSvyr^{-1}$ for the normal scenario, $1mSvyr^{-1}$ for the well scenario). It was concluded that the DSRSs disposal system would maintain environmental safety over a long-time. Moreover, the partition coefficient of Np in host rock, Darcy velocity in host rock, and density of the host rock were the most sensitive parameters in predicting exposure dose in the safety assessment.

• Speech Sciences
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• v.5 no.2
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• pp.17-26
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• 1999

It has been claimed that Korean mid-vocalic voiceless unaspirated lax stops are phonetically realized with voicing throughout the oral closure phase. Acoustic measurements were undertaken to examine the claim with four Korean native speakers using /$V_1CV_2$/ words where the vowel ($V_1\;=\;V_2$) was /i, a, u/ and the C was voiceless unaspirated lax stops /p, t, k/. Findings: (1) During mid-vocalic stops /k/ and /p/ the vowel /u/ was accompanied generally by a significant increase in voice cessation time as percentage of the oral closure interval (PCT) than the vowel /a/, regardless of subjects, whereas in mid-vocalic alveolar stop /t/ the effects of vowels on PCT were subject-dependent, (2) The effects of vowels on PCT were significantly greater in mid-vocalic /k/ than /p/, regardless of subjects, (3) The mean PCT, averaged across six tokens, ranged from 17% to100%, giving overall mean 61% in which the standard deviation was ${\pm}30$, and (4) Overall % of the total of mid-vocalic unaspirated lax stops were produced with a substantial period of devocing and voicing lag. Considering these results, it is difficult to agree with the existing claims that Korean voiceless unaspirated lax stops are phonetically realized with voicing throughout the oral closure phase. Other phonetic variables, including the durations of pre/post-stop vowels, voice onset time, voice cessation time, and the duration of oral closure, were measured.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.230-233
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• 2007

In the literature on the tense consonants in Korean, it has been proposed that this consonant is underlyingly represented by a single consonant (the singleton hypothesis) and that it is represented by a sequence of two lenis consonants (the geminate hypothesis). One piece of the empirical evidence supporting the geminate hypothesis is that the closure duration of tense consonants in intervocalic position is more than twice as long in comparison with their lenis counterparts. In this paper, we report on the closure duration of three types of plosives in various phonotactically permitted contexts in Korean. The results of the measurement show that the duration of the tense consonants in post-sonorant contexts is reduced by a third in comparison with that of the intervocalic ones. These temporal differences suggest that the measurement of closure durations in intervocalic position alone is not sufficient to sustain the geminate hypothesis.

• Journal of Chest Surgery
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• v.26 no.11
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• pp.845-850
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• 1993

Post-Pneumonectomy Empyema[PPE] is a relatively uncommon but serious complication. And the management of it remains a disturbing and controversial area in the field of general thoracic surgery. Many methods have described and have had varying degrees of success. For the purpose of providing the guideline for management of post-pneumonectomy empyema, we reviewed our experiences of treatment of PPE from January 1985. to December 1992. There were 17 cases, which consist 7.9% of all pneumonectomy cases for that period. There were 13 male and 4 female patients with mean age of 47.1$\pm$ 16.2 yrs old. Both chest has the same incidence. The most common disease for prior pneumonectomy was tuberculosis, but the PPE was the most frequently occurred in empyema. The duration between pneumonectomy and PPE was 44.7 $\pm$81.1 months, where 58.8% of patients occurred within 1 month. Fever was the most frequent complaint and wound dischrge was detected in less than half of patients. There were 2 in-hospital mortalities.Mostly, in 13 cases, we did Eloesser operation. Five of them could finish second Clagett procedure, but one had recurrence. Four bronchopleural fistular patients underwent 3 single stage muscle flap closure and 1 direct closure with modified Clagett procedure. None had recurrence. Mean follow-up duration is 30.9\ulcorner22.3 months. There was 1 late death which was not related to PPE but to Malignancy recurrence.