• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.9-15
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• 2021

Miniaturization of semiconductor devices has recently faced a physical limitation. To overcome this, 3D packaging in which semiconductor devices are vertically stacked has been actively developed. 3D packaging requires three unit processes of TSV, wafer grinding, and bonding, and among these, copper bonding is becoming very important for high performance and fine-pitch in 3D packaging. In this study, the effects of Ti nanolayer on the antioxidation of copper surface and low-temperature Cu bonding was investigated. The diffusion rate of Ti into Cu is faster than Cu into Ti in the temperature ranging from room temperature to 200℃, which shows that the titanium nanolayer can be effective for low-temperature copper bonding. The 12nm-thick titanium layer was uniformly deposited on the copper surface, and the surface roughness (R_q) was lowered from 4.1 nm to 3.2 nm. Cu bonding using Ti nanolayer was carried out at 200℃ for 1 hour, and then annealing at the same temperature and time. The average shear strength measured after bonding was 13.2 MPa.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.91-97
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• 2022

The wettability and rheological properties of solder paste with the size of the solder powder were evaluated. To formulate the solder paste, three types of solder powder were used: T4 (20~28 ㎛), T5 (15~25 ㎛), and T6 (5~15 ㎛). The viscosities of the T4, T5, and T6 solder pastes at 10 RPM were 155, 263, and 418 Pa·s, respectively. After 7 days, the viscosity of the T4 solder paste slightly increased by 2.6% and that of T5 was increased by 20.6%. The viscosity of the T6 solder paste after 7 days could not be measured due to high viscosity. The viscosity variation with solder particle size also affected on the printability of the solder. In the case of the T4 solder paste, printability, slump, bridging, and soldering properties were excellent. On the other hand, T5 showed slight dewetting and solder ball defects. Especially, T6, which the smallest powder size, showed poor printability and dewetting at the edge of solder.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.359-365
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• 2023

In order to satisfy the requirements of dynamic X-ray imaging with high frame rate and low image lag, minimizing parasitic capacitance in photodiode and overlapped electrodes in pixels is critically required. This study presents duoPIX^TM dynamic X-ray imaging sensor composing of readout thin film transistor, reset thin film transistor and photodiode in a pixel. Furthermore, dynamic X-ray detector using duoPIX^TM imaging sensor was manufactured and evaluated its X-ray imaging performances such as frame rate, sensitivity, noise, MTF and image lag. duoPIX^TM dynamic X-ray detector has 150 × 150 mm² imaging area, 73 um pixel pitch, 2048 × 2048 matrix resolution(4.2M pixels) and maximum 50 frames per second. By means of comparison with conventional dynamic X-ray detector, duoPIX^TM dynamic X-ray detector showed overall better performances than conventional dynamic X-ray detector as shown in the previous study.

• Phonetics and Speech Sciences
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• v.15 no.3
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• pp.53-58
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• 2023

After thyroidectomy, some patients who show normal vocal cord movement still complain of subjective voice problems, which could lead to a decrease in quality of life related to communication. This study aims to investigate the effectiveness of a newly designed voice therapy applying neck exercise and semi-occluded vocal tract exercise (SOVTE) to improve voice problems after thyroidectomy without neurological injury. For this purpose, voice therapy was randomly assigned to 10 women who received thyroidectomy. Acoustic analysis [fundamental frequency, jitter, shimmer, noise-to-harmonics ratio, min Voice Range Profile (VRP), max VRP, VRP] was performed before and after surgery and immediately after voice therapy to compare voice changes. The study showed a statistically significant increase in max VRP and VRP after voice therapy compared to before surgery. These results suggest that the voice therapy methods in this study effectively improve a major symptom of voice problems after thyroidectomy, specifically the reduction in the high-frequency range. However, this study was limited in the number of s participants and did not control for the type of surgery. Therefore, further research utilizing larger sample sizes and controlled variables is needed to investigate the long-term effects of voice therapy.

• Korean Journal of Culture and Social Issue
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• v.12 no.2
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• pp.101-114
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• 2006

This study was examined the effective nonverbal behavior cues of detecting suspects' lies in the investigation scene. In order to search the suspects who drank the alcohol liquor without a permission, 18 soldiers were interviewed. 8 solders had drunken alcohol and had lied when was asked(lie group). The other 10 soldiers hadn't drunken alcohol and had told the truth(truth group). The mean frequencies of nonverbal behaviors were compared lie group with truth group. The following behaviors were measured by frequency: vocal characteristics (high pitch of voice, speech hesitations, speech error, frequency of pauses, period of pauses, latency period), facial characteristics (gaze, smile, touching face, blinking, facial micro-expression), body movement (illustrators, hand and finger movement, leg and foot movement, head movement, trunk movement, shifting position). As results, this study found that deception cues were periods and frequencies of pause, micro-expression, head movements. The lie group had less periods and frequencies of pause, and more micro-expression, head movements than truth group. But, this study didn't found Othello's error cues.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.965-972
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• 2022

This is a basic study to establish marine activity criteria based on the seakeeping performance of less than 10-tons fishing vessels. These vessels account for approximately 95% of Korea's currently registered fishing vessels, and accidents and loss of life are also occurring during marine activities such as navigation, and fishing. Accordingly, the Ministry of Oceans and Fisheries has set a regulation of vessel traf ic control to restrict the operation of fishing vessels when the high seas watch takes effect, but it is applied equally without criteria according to the ship ton level and wave height; therefore, many differences may exist in ship fluctuations. Because the fluctuation of the ship owing to the wave height can be a factor in marine accidents by reducing the sense of boarding and performance of equipment, the seakeeping performance must be reviewed during waves to secure safe marine activities such as navigation and fishing. However, the review for the fishing vessel of established marine activity criteria based on the seakeeping performance is insufficient. Accordingly, the seakeeping performance was evaluated for a 10-ton class (G/T 9.77 tons) fishing vessel in Korea, and the level of marine activity according to the significant wave height and ship speed was interpreted by applying the operation and survival of the established seakeeping performance criteria. The analysis results indicated that the roll of the ship exceeded the operation criteria from 0.4m and the survival criteria from 2.2m. The pitch of the ship exceeded the operation criteria from 1.7m and did not exceed the survival criteria until 3.0m. However, the rolling exceeding the survival criteria from 2.2m may not be safe. Therefore, fishing vessels with less than 10-tons can leave before the high seas watch takes effect. However, they did not satisfy the criteria for evaluating the performance of the sea in relation to marine activities. Although this study was limitedly evaluated for 10-ton fishing vessels, it is expected to be of great help in preparing marine activity criteria.

• Journal of the Korean Wood Science and Technology
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• v.39 no.4
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• pp.318-325
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• 2011

Pitch pine (Pinus rigida Miller) retaining walls using Steel bar, of which the constructability and strength performance are good at the construction site, were manufactured and their strength properties were evaluated. The wooden retaining wall using Steel bar was piled into four stories stretcher and three stories header, which is 770 mm high, 2,890 mm length and 782 mm width. Retaining wall was made by inserting stretchers into Steel bar after making 18 mm diameter of holes at top and bottom stretcher, and then stacking other stretchers and headers which have a slit of 66 mm depth and 18 mm width. The strength properties of retaining walls were investigated by horizontal loading test, and the deformation of structure by image processing (AlCON 3D OPA-PRO system). Joint (Type-A) made with a single long stretcher and two headers, and joint (Type-B) made with two short stretchers connected with half lap joint and two headers were in the retaining wall using Steel bar. The compressive shear strength of joint was tested. Three replicates were used in each test. In horizontal loading test the strength was 1.6 times stronger in wooden retaining wall using Steel bar than in wooden retaining wall using square timber. The timber and joints were not fractured in the test. When testing compressive shear strength, the maximum load of type-A and Type-B was 130.13 kN and 130.6 kN, respectively. Constructability and strength were better in the wooden retaining wall using Steel bar than in wooden retaining wall using square timber.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.115-122
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• 2015

Purpose : The aim of this study, evaluate the accuracy of HeaxPOD evo RT system using the non-coplanar beam. Materials and Methods : 13 treatment plans are used which applied non-coplanar beams and 10 treatment plans which coplanar beams are used. the correction value what adjust to 6D couch is determined by each patient's setup errors only rotation direction. The study executed followings. first, Applying the correction value, measure the point dose and calculate the ${\gamma}$-index(${\gamma}=3%$ / 3 mm, ${\gamma}=2%$ / 2 mm). second, acquire data as previous methods without correction by HexaPOD. Results : For comparing the two results, we find out the more precise applying HexaPOD by point dose 0.2% in coplanar and non-coplanar. in the case of ${\gamma}$-index<1(${\gamma}=3%$ / 3 mm), more precise 2.2% in coplanar and 7% in Non-coplanar. Particularly, ${\gamma}$-index<1(2% / 2 mm) show the difference 9.2% in coplanar and 15.1% non-coplanar between apply HexaPOD and dose not apply HexaPOD. Conclusion : Using the HexaPOD is more precise than without HexaPOD. It suggests that HexaPOD evo RT system is very useful for precise and high dose delivery.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.2
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• pp.113-122
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• 2007

Purpose: We proposed the method using dose-volume Histogram index to compare prospective plan trials in tomotherapy planning optimization. Materials and Methods: For 3 patients in cranial region, thorax and abdominal region, we acquired computed tomography images with PQ 5000 in each case. Then we delineated target structure and normal organ contour with pinnacle Ver 7.6c, after transferred each data to tomotherapy planning system (hi-art system Ver 2.0), we optimized 3 plan trials in each case that used differ from beam width, pitch, importance. We analyzed 3 plan trials in each region with isodose distribution, dose-volume histogram and dose statistics. Also we verified 3 plan trials with specialized DVH-indexes that is dose homogeneity index in target organ, conformity index around target structure and dose gradient index in non-target structures. Results: We compared with the similarity of results that the one is decide the best plan trial using isodose distribution, dose volume histogram and dose statistics, and the another is using DVH-indexes. They all decided the same plan trial to better result in each case. Conclusion: In some of case, it was appeared a little difference of results that used to DVH-index for comparison of plan trial in tomotherapy by special goal in it. But because DVH-index represented both dose distribution in target structure and high dose risk about normal tissue, it will be reasonable method for comparison of many plan trials before the tomotherapy treatments.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.246-246
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• 1996

Purpose: Some of the properties of the prosodic phrasing and some acoustic and phonological effects of contrastive focus on the tonal pattern of Seoul Korean is explored based on a brief experiment of analyzing the fundamental frequency(=FO) contour of the speech of the author. Data Base and Analysis Procedures: The examples were chosen to contain mostly nasal and liquid consonants, since it is difficult to track down the formants in stops and fricatives during their corresponding consonantal intervals and stops may yield an effect of unwanted increase in the FO value due to their burst into the following vowel. All examples were recorded three times and the spectrum of the most stable repetition was generated, from which the FO contour of each sentence was obtained, the peaks with a value higher than 250Hz being interpreted as a high tone (=H). The result is then discussed within the prosodic hierarchy framework of Selkirk (1986) and compared with the tonal pattern of the Northern Kyungsang dialect of Korean reported in Kenstowicz & Sohn (1996). Prosodic Phrasing: In N.K. Korean, H never appears both on the object and on the verb in a neutral sentence, which indicates the object and the verb form a single Phonological Phrase ($={\phi}$), given that there is only one pitch peak for each $={\phi}$. However, Seoul Korean shows that both the object and the verb have H of their own, indicating that they are not contained in one $={\phi}$. This violates the Optimality constraint of Wrap-XP (=Enclose a lexical head and its arguments in one $={\phi}$), while N.K. Korean obeys the constraint by grouping a VP in a single $={\phi}$. This asymmetry can be resolved through a constraint that favors the separate grouping of each lexical category and is ranked higher than Wrap-XP in Seoul Korean but vice versa in N.K. Korean; $Align-x^{lex}$ (=Align the left edge of a lexical category with that of a $={\phi}$). (1) nuna-ka manll-ll mEk-nIn-ta ('sister-NOM garlic-ACC eat-PRES-DECL') a. (LLH) (LLH) (HLL) ----Seoul Korean b. (LLH) (LLL LHL) ----N.K. Korean Focus and Phrasing: Two major effects of contrastive focus on phonological phrasing are found in Seoul Korean: (a) the peak of an Intonatioanl Phrase (=IP) falls on the focused element; and (b) focus has the effect of deleting all the following prosodic structures. A focused element always attracts the peak of IP, showing an increase of approximately 30Hz compared with the peak of a non-focused IP. When a subject is focused, no H appears either on the object or on the verb and a focused object is never followed by a verb with H. The post-focus deletion of prosodic boundaries is forced through the interaction of StressFocus (=If F is a focus and DF is its semantic domain, the highest prominence in DF will be within F) and Rightmost-IP (=The peak of an IP projects from the rightmost $={\phi}$). First Stress-F requires the peak of IP to fall on the focused element. Then to avoid violating Rightmost-IP, all the boundaries after the focused element should delete, minimizing the number of $={\phi}$'s intervening from the right edge of IP. (2) (omitted) Conclusion: In general, there seems to be no direct alignment constraints between the syntactically focused element and the edge of $={\phi}$ determined in phonology; all the alignment effects come from a single requirement that the peak of IP projects from the rightmost $={\phi}$ as proposed in Truckenbrodt (1995).